Showing 23 of 23 total issues
Similar blocks of code found in 2 locations. Consider refactoring. Open
getKwhDay(count = 1, db) {
return this.getRangeFromEnd(count, 'days', db)
.then(values => this.transformCountToKwh(values, 'perHour'))
.then(values => this.getCalculatedKwhSummary(values))
.then(summary => {
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 199.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Similar blocks of code found in 2 locations. Consider refactoring. Open
getKwhWeek(count = 1, db) {
return this.getRangeFromEnd(count, 'weeks', db)
.then(values => this.transformCountToKwh(values, 'perDay'))
.then(values => this.getCalculatedKwhSummary(values))
.then(summary => {
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 199.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Similar blocks of code found in 2 locations. Consider refactoring. Open
return this.getRangeFromEnd(count, 'hours', db)
.then(values => {
const summary = this.getCalculatedKwhSummary(values);
summary.description = 'kWh consumption per hour for ' + count + ' hours.';
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 127.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Similar blocks of code found in 2 locations. Consider refactoring. Open
return this.getRangeFromEnd(count, 'months', db)
.then(values => values.map(item => {
item.perDay = util.pulsesToKwh(item.perDay);
return item;
}))
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 127.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
File power-meter-kwh.js
has 340 lines of code (exceeds 250 allowed). Consider refactoring. Open
/**
* Power Meter API controller object.
*
* Power meter app. An express frontend to reading a power meter with a
Similar blocks of code found in 2 locations. Consider refactoring. Open
kwh.handleDay(req, res, redis)
.then(data => {
res.setHeader('Cache-Control', 'public, max-age=864000');
res.json(data);
})
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 70.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Similar blocks of code found in 2 locations. Consider refactoring. Open
kwh.handleDateMonth(req, res, redis)
.then(data => {
data.version = util.version;
data.description = (
`kWh usage for ${util.monthName(req.params.month)}, ${req.params.year}.`
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 70.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Function getKwhSeconds
has 40 lines of code (exceeds 25 allowed). Consider refactoring. Open
getKwhSeconds(count, db) {
return this.getSecondsRangeFromEnd(count, db)
.then(values => {
const summary = {kwh: {}, watts: {}};
Function putMeterTotal
has 35 lines of code (exceeds 25 allowed). Consider refactoring. Open
putMeterTotal(value, db) {
debug('starting ctrl.meter.total.put: ', value);
if (typeof value !== 'number' || isNaN(value)) {
throw new TypeError(
`Value (${value}) passed as argument must be a valid Integer or Float.`
Function handleDay
has 28 lines of code (exceeds 25 allowed). Consider refactoring. Open
handleDay(req, res, redis) {
const opts = req.params;
this.assertYear(opts.year);
this.assertMonth(opts.year, opts.month);
Missing JSDoc for parameter 'db'. Open
/**
- Read upRead up
- Exclude checks
enforce valid JSDoc comments (valid-jsdoc)
JSDoc generates application programming interface (API) documentation from specially-formatted comments in JavaScript code. For example, this is a JSDoc comment for a function:
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
If comments are invalid because of typing mistakes, then documentation will be incomplete.
If comments are inconsistent because they are not updated when function definitions are modified, then readers might become confused.
Rule Details
This rule enforces valid and consistent JSDoc comments. It reports any of the following problems:
- missing parameter tag:
@arg
,@argument
, or@param
- inconsistent order of parameter names in a comment compared to the function or method
- missing return tag:
@return
or@returns
- missing parameter or return type
- missing parameter or return description
- syntax error
This rule does not report missing JSDoc comments for classes, functions, or methods.
Note: This rule does not support all of the Google Closure documentation tool's use cases. As such, some code such as (/**number*/ n => n * 2);
will be flagged as missing appropriate function JSDoc comments even though /**number*/
is intended to be a type hint and not a documentation block for the function. We don't recommend using this rule if you use type hints in this way.
Examples of incorrect code for this rule:
/*eslint valid-jsdoc: "error"*/
// expected @param tag for parameter num1 but found num instead
// missing @param tag for parameter num2
// missing return type
/**
* Add two numbers.
* @param {number} num The first number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// missing brace
// missing @returns tag
/**
* @param {string name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
// missing parameter type for num1
// missing parameter description for num2
/**
* Represents a sum.
* @constructor
* @param num1 The first number.
* @param {number} num2
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
Examples of correct code for this rule:
/*eslint valid-jsdoc: "error"*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// default options allow missing function description
// return type `void` means the function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
// @constructor tag allows missing @returns tag
/**
* Represents a sum.
* @constructor
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
// class constructor allows missing @returns tag
/**
* Represents a sum.
*/
class Sum {
/**
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
constructor(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
}
// @abstract tag allows @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
// @override tag allows missing @param and @returns tags
class WonderfulWidget extends Widget {
/**
* @override
*/
mustRender (state) {
return state !== this.state; // shallow comparison
}
}
Options
This rule has an object option:
-
"prefer"
enforces consistent documentation tags specified by an object whose properties mean instead of key use value (for example,"return": "returns"
means instead of@return
use@returns
) -
"preferType"
enforces consistent type strings specified by an object whose properties mean instead of key use value (for example,"object": "Object"
means instead ofobject
useObject
) -
"requireReturn"
requires a return tag:-
true
(default) even if the function or method does not have areturn
statement (this option value does not apply to constructors) -
false
if and only if the function or method has areturn
statement (this option value does apply to constructors)
-
-
"requireReturnType": false
allows missing type in return tags -
"matchDescription"
specifies (as a string) a regular expression to match the description in each JSDoc comment (for example,".+"
requires a description; this option does not apply to descriptions in parameter or return tags) -
"requireParamDescription": false
allows missing description in parameter tags -
"requireReturnDescription": false
allows missing description in return tags
prefer
Examples of additional incorrect code for this rule with sample "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" }
options:
/*eslint valid-jsdoc: ["error", { "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @arg {int} num1 The first number.
* @arg {int} num2 The second number.
* @return {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Represents a sum.
* @class
* @argument {number} num1 The first number.
* @argument {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @virtual
* @argument {Object} state The new state of the widget.
* @return {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
preferType
Examples of additional incorrect code for this rule with sample "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" }
options:
/*eslint valid-jsdoc: ["error", { "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {Number} num1 The first number.
* @param {Number} num2 The second number.
* @returns {Number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Output a greeting as a side effect.
* @param {String} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {object} state The new state of the widget.
* @returns {Boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
requireReturn
Examples of additional incorrect code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
// unexpected @returns tag because function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {string} The greeting.
*/
function greet(name) {
console.log("Hello " + name);
}
// add @abstract tag to allow @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
Example of additional correct code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
/**
* @param {string} name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
requireReturnType
Example of additional correct code for this rule with the "requireReturnType": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnType": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
matchDescription
Example of additional incorrect code for this rule with a sample "matchDescription": ".+"
option:
/*eslint valid-jsdoc: ["error", { "matchDescription": ".+" }]*/
// missing function description
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
requireParamDescription
Example of additional correct code for this rule with the "requireParamDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireParamDescription": false }]*/
/**
* Add two numbers.
* @param {int} num1
* @param {int} num2
* @returns {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
requireReturnDescription
Example of additional correct code for this rule with the "requireReturnDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnDescription": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number}
*/
function add(num1, num2) {
return num1 + num2;
}
When Not To Use It
If you aren't using JSDoc, then you can safely turn this rule off.
Further Reading
Related Rules
- [require-jsdoc](require-jsdoc.md) Source: http://eslint.org/docs/rules/
Missing JSDoc for parameter 'db'. Open
/**
- Read upRead up
- Exclude checks
enforce valid JSDoc comments (valid-jsdoc)
JSDoc generates application programming interface (API) documentation from specially-formatted comments in JavaScript code. For example, this is a JSDoc comment for a function:
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
If comments are invalid because of typing mistakes, then documentation will be incomplete.
If comments are inconsistent because they are not updated when function definitions are modified, then readers might become confused.
Rule Details
This rule enforces valid and consistent JSDoc comments. It reports any of the following problems:
- missing parameter tag:
@arg
,@argument
, or@param
- inconsistent order of parameter names in a comment compared to the function or method
- missing return tag:
@return
or@returns
- missing parameter or return type
- missing parameter or return description
- syntax error
This rule does not report missing JSDoc comments for classes, functions, or methods.
Note: This rule does not support all of the Google Closure documentation tool's use cases. As such, some code such as (/**number*/ n => n * 2);
will be flagged as missing appropriate function JSDoc comments even though /**number*/
is intended to be a type hint and not a documentation block for the function. We don't recommend using this rule if you use type hints in this way.
Examples of incorrect code for this rule:
/*eslint valid-jsdoc: "error"*/
// expected @param tag for parameter num1 but found num instead
// missing @param tag for parameter num2
// missing return type
/**
* Add two numbers.
* @param {number} num The first number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// missing brace
// missing @returns tag
/**
* @param {string name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
// missing parameter type for num1
// missing parameter description for num2
/**
* Represents a sum.
* @constructor
* @param num1 The first number.
* @param {number} num2
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
Examples of correct code for this rule:
/*eslint valid-jsdoc: "error"*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// default options allow missing function description
// return type `void` means the function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
// @constructor tag allows missing @returns tag
/**
* Represents a sum.
* @constructor
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
// class constructor allows missing @returns tag
/**
* Represents a sum.
*/
class Sum {
/**
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
constructor(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
}
// @abstract tag allows @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
// @override tag allows missing @param and @returns tags
class WonderfulWidget extends Widget {
/**
* @override
*/
mustRender (state) {
return state !== this.state; // shallow comparison
}
}
Options
This rule has an object option:
-
"prefer"
enforces consistent documentation tags specified by an object whose properties mean instead of key use value (for example,"return": "returns"
means instead of@return
use@returns
) -
"preferType"
enforces consistent type strings specified by an object whose properties mean instead of key use value (for example,"object": "Object"
means instead ofobject
useObject
) -
"requireReturn"
requires a return tag:-
true
(default) even if the function or method does not have areturn
statement (this option value does not apply to constructors) -
false
if and only if the function or method has areturn
statement (this option value does apply to constructors)
-
-
"requireReturnType": false
allows missing type in return tags -
"matchDescription"
specifies (as a string) a regular expression to match the description in each JSDoc comment (for example,".+"
requires a description; this option does not apply to descriptions in parameter or return tags) -
"requireParamDescription": false
allows missing description in parameter tags -
"requireReturnDescription": false
allows missing description in return tags
prefer
Examples of additional incorrect code for this rule with sample "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" }
options:
/*eslint valid-jsdoc: ["error", { "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @arg {int} num1 The first number.
* @arg {int} num2 The second number.
* @return {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Represents a sum.
* @class
* @argument {number} num1 The first number.
* @argument {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @virtual
* @argument {Object} state The new state of the widget.
* @return {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
preferType
Examples of additional incorrect code for this rule with sample "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" }
options:
/*eslint valid-jsdoc: ["error", { "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {Number} num1 The first number.
* @param {Number} num2 The second number.
* @returns {Number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Output a greeting as a side effect.
* @param {String} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {object} state The new state of the widget.
* @returns {Boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
requireReturn
Examples of additional incorrect code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
// unexpected @returns tag because function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {string} The greeting.
*/
function greet(name) {
console.log("Hello " + name);
}
// add @abstract tag to allow @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
Example of additional correct code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
/**
* @param {string} name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
requireReturnType
Example of additional correct code for this rule with the "requireReturnType": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnType": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
matchDescription
Example of additional incorrect code for this rule with a sample "matchDescription": ".+"
option:
/*eslint valid-jsdoc: ["error", { "matchDescription": ".+" }]*/
// missing function description
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
requireParamDescription
Example of additional correct code for this rule with the "requireParamDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireParamDescription": false }]*/
/**
* Add two numbers.
* @param {int} num1
* @param {int} num2
* @returns {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
requireReturnDescription
Example of additional correct code for this rule with the "requireReturnDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnDescription": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number}
*/
function add(num1, num2) {
return num1 + num2;
}
When Not To Use It
If you aren't using JSDoc, then you can safely turn this rule off.
Further Reading
Related Rules
- [require-jsdoc](require-jsdoc.md) Source: http://eslint.org/docs/rules/
Trailing spaces not allowed. Open
* GET /power/kwh/month
- Read upRead up
- Exclude checks
disallow trailing whitespace at the end of lines (no-trailing-spaces)
Sometimes in the course of editing files, you can end up with extra whitespace at the end of lines. These whitespace differences can be picked up by source control systems and flagged as diffs, causing frustration for developers. While this extra whitespace causes no functional issues, many code conventions require that trailing spaces be removed before check-in.
Rule Details
This rule disallows trailing whitespace (spaces, tabs, and other Unicode whitespace characters) at the end of lines.
Examples of incorrect code for this rule:
/*eslint no-trailing-spaces: "error"*/
var foo = 0;//•••••
var baz = 5;//••
//•••••
Examples of correct code for this rule:
/*eslint no-trailing-spaces: "error"*/
var foo = 0;
var baz = 5;
Options
This rule has an object option:
-
"skipBlankLines": false
(default) disallows trailing whitespace on empty lines -
"skipBlankLines": true
allows trailing whitespace on empty lines
skipBlankLines
Examples of correct code for this rule with the { "skipBlankLines": true }
option:
/*eslint no-trailing-spaces: ["error", { "skipBlankLines": true }]*/
var foo = 0;
var baz = 5;
//•••••
Source: http://eslint.org/docs/rules/
'next' is defined but never used. Open
route.get('/kwh/:type/:count?', (req, res, next) => {
- Read upRead up
- Exclude checks
Disallow Unused Variables (no-unused-vars)
Variables that are declared and not used anywhere in the code are most likely an error due to incomplete refactoring. Such variables take up space in the code and can lead to confusion by readers.
Rule Details
This rule is aimed at eliminating unused variables, functions, and parameters of functions.
A variable is considered to be used if any of the following are true:
- It represents a function that is called (
doSomething()
) - It is read (
var y = x
) - It is passed into a function as an argument (
doSomething(x)
) - It is read inside of a function that is passed to another function (
doSomething(function() { foo(); })
)
A variable is not considered to be used if it is only ever assigned to (var x = 5
) or declared.
Examples of incorrect code for this rule:
/*eslint no-unused-vars: "error"*/
/*global some_unused_var*/
// It checks variables you have defined as global
some_unused_var = 42;
var x;
// Write-only variables are not considered as used.
var y = 10;
y = 5;
// A read for a modification of itself is not considered as used.
var z = 0;
z = z + 1;
// By default, unused arguments cause warnings.
(function(foo) {
return 5;
})();
// Unused recursive functions also cause warnings.
function fact(n) {
if (n < 2) return 1;
return n * fact(n - 1);
}
// When a function definition destructures an array, unused entries from the array also cause warnings.
function getY([x, y]) {
return y;
}
Examples of correct code for this rule:
/*eslint no-unused-vars: "error"*/
var x = 10;
alert(x);
// foo is considered used here
myFunc(function foo() {
// ...
}.bind(this));
(function(foo) {
return foo;
})();
var myFunc;
myFunc = setTimeout(function() {
// myFunc is considered used
myFunc();
}, 50);
// Only the second argument from the descructured array is used.
function getY([, y]) {
return y;
}
exported
In environments outside of CommonJS or ECMAScript modules, you may use var
to create a global variable that may be used by other scripts. You can use the /* exported variableName */
comment block to indicate that this variable is being exported and therefore should not be considered unused.
Note that /* exported */
has no effect for any of the following:
- when the environment is
node
orcommonjs
- when
parserOptions.sourceType
ismodule
- when
ecmaFeatures.globalReturn
istrue
The line comment // exported variableName
will not work as exported
is not line-specific.
Examples of correct code for /* exported variableName */
operation:
/* exported global_var */
var global_var = 42;
Options
This rule takes one argument which can be a string or an object. The string settings are the same as those of the vars
property (explained below).
By default this rule is enabled with all
option for variables and after-used
for arguments.
{
"rules": {
"no-unused-vars": ["error", { "vars": "all", "args": "after-used", "ignoreRestSiblings": false }]
}
}
vars
The vars
option has two settings:
-
all
checks all variables for usage, including those in the global scope. This is the default setting. -
local
checks only that locally-declared variables are used but will allow global variables to be unused.
vars: local
Examples of correct code for the { "vars": "local" }
option:
/*eslint no-unused-vars: ["error", { "vars": "local" }]*/
/*global some_unused_var */
some_unused_var = 42;
varsIgnorePattern
The varsIgnorePattern
option specifies exceptions not to check for usage: variables whose names match a regexp pattern. For example, variables whose names contain ignored
or Ignored
.
Examples of correct code for the { "varsIgnorePattern": "[iI]gnored" }
option:
/*eslint no-unused-vars: ["error", { "varsIgnorePattern": "[iI]gnored" }]*/
var firstVarIgnored = 1;
var secondVar = 2;
console.log(secondVar);
args
The args
option has three settings:
-
after-used
- only the last argument must be used. This allows you, for instance, to have two named parameters to a function and as long as you use the second argument, ESLint will not warn you about the first. This is the default setting. -
all
- all named arguments must be used. -
none
- do not check arguments.
args: after-used
Examples of incorrect code for the default { "args": "after-used" }
option:
/*eslint no-unused-vars: ["error", { "args": "after-used" }]*/
// 1 error
// "baz" is defined but never used
(function(foo, bar, baz) {
return bar;
})();
Examples of correct code for the default { "args": "after-used" }
option:
/*eslint no-unused-vars: ["error", {"args": "after-used"}]*/
(function(foo, bar, baz) {
return baz;
})();
args: all
Examples of incorrect code for the { "args": "all" }
option:
/*eslint no-unused-vars: ["error", { "args": "all" }]*/
// 2 errors
// "foo" is defined but never used
// "baz" is defined but never used
(function(foo, bar, baz) {
return bar;
})();
args: none
Examples of correct code for the { "args": "none" }
option:
/*eslint no-unused-vars: ["error", { "args": "none" }]*/
(function(foo, bar, baz) {
return bar;
})();
ignoreRestSiblings
The ignoreRestSiblings
option is a boolean (default: false
). Using a Rest Property it is possible to "omit" properties from an object, but by default the sibling properties are marked as "unused". With this option enabled the rest property's siblings are ignored.
Examples of correct code for the { "ignoreRestSiblings": true }
option:
/*eslint no-unused-vars: ["error", { "ignoreRestSiblings": true }]*/
// 'type' is ignored because it has a rest property sibling.
var { type, ...coords } = data;
argsIgnorePattern
The argsIgnorePattern
option specifies exceptions not to check for usage: arguments whose names match a regexp pattern. For example, variables whose names begin with an underscore.
Examples of correct code for the { "argsIgnorePattern": "^_" }
option:
/*eslint no-unused-vars: ["error", { "argsIgnorePattern": "^_" }]*/
function foo(x, _y) {
return x + 1;
}
foo();
caughtErrors
The caughtErrors
option is used for catch
block arguments validation.
It has two settings:
-
none
- do not check error objects. This is the default setting. -
all
- all named arguments must be used.
caughtErrors: none
Not specifying this rule is equivalent of assigning it to none
.
Examples of correct code for the { "caughtErrors": "none" }
option:
/*eslint no-unused-vars: ["error", { "caughtErrors": "none" }]*/
try {
//...
} catch (err) {
console.error("errors");
}
caughtErrors: all
Examples of incorrect code for the { "caughtErrors": "all" }
option:
/*eslint no-unused-vars: ["error", { "caughtErrors": "all" }]*/
// 1 error
// "err" is defined but never used
try {
//...
} catch (err) {
console.error("errors");
}
caughtErrorsIgnorePattern
The caughtErrorsIgnorePattern
option specifies exceptions not to check for usage: catch arguments whose names match a regexp pattern. For example, variables whose names begin with a string 'ignore'.
Examples of correct code for the { "caughtErrorsIgnorePattern": "^ignore" }
option:
/*eslint no-unused-vars: ["error", { "caughtErrorsIgnorePattern": "^ignore" }]*/
try {
//...
} catch (ignoreErr) {
console.error("errors");
}
When Not To Use It
If you don't want to be notified about unused variables or function arguments, you can safely turn this rule off. Source: http://eslint.org/docs/rules/
Missing semicolon. Open
}
- Read upRead up
- Exclude checks
require or disallow semicolons instead of ASI (semi)
JavaScript is unique amongst the C-like languages in that it doesn't require semicolons at the end of each statement. In many cases, the JavaScript engine can determine that a semicolon should be in a certain spot and will automatically add it. This feature is known as automatic semicolon insertion (ASI) and is considered one of the more controversial features of JavaScript. For example, the following lines are both valid:
var name = "ESLint"
var website = "eslint.org";
On the first line, the JavaScript engine will automatically insert a semicolon, so this is not considered a syntax error. The JavaScript engine still knows how to interpret the line and knows that the line end indicates the end of the statement.
In the debate over ASI, there are generally two schools of thought. The first is that we should treat ASI as if it didn't exist and always include semicolons manually. The rationale is that it's easier to always include semicolons than to try to remember when they are or are not required, and thus decreases the possibility of introducing an error.
However, the ASI mechanism can sometimes be tricky to people who are using semicolons. For example, consider this code:
return
{
name: "ESLint"
};
This may look like a return
statement that returns an object literal, however, the JavaScript engine will interpret this code as:
return;
{
name: "ESLint";
}
Effectively, a semicolon is inserted after the return
statement, causing the code below it (a labeled literal inside a block) to be unreachable. This rule and the [no-unreachable](no-unreachable.md) rule will protect your code from such cases.
On the other side of the argument are those who says that since semicolons are inserted automatically, they are optional and do not need to be inserted manually. However, the ASI mechanism can also be tricky to people who don't use semicolons. For example, consider this code:
var globalCounter = { }
(function () {
var n = 0
globalCounter.increment = function () {
return ++n
}
})()
In this example, a semicolon will not be inserted after the first line, causing a run-time error (because an empty object is called as if it's a function). The [no-unexpected-multiline](no-unexpected-multiline.md) rule can protect your code from such cases.
Although ASI allows for more freedom over your coding style, it can also make your code behave in an unexpected way, whether you use semicolons or not. Therefore, it is best to know when ASI takes place and when it does not, and have ESLint protect your code from these potentially unexpected cases. In short, as once described by Isaac Schlueter, a \n
character always ends a statement (just like a semicolon) unless one of the following is true:
- The statement has an unclosed paren, array literal, or object literal or ends in some other way that is not a valid way to end a statement. (For instance, ending with
.
or,
.) - The line is
--
or++
(in which case it will decrement/increment the next token.) - It is a
for()
,while()
,do
,if()
, orelse
, and there is no{
- The next line starts with
[
,(
,+
,*
,/
,-
,,
,.
, or some other binary operator that can only be found between two tokens in a single expression.
Rule Details
This rule enforces consistent use of semicolons.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires semicolons at the end of statements -
"never"
disallows semicolons as the end of statements (except to disambiguate statements beginning with[
,(
,/
,+
, or-
)
Object option:
-
"omitLastInOneLineBlock": true
ignores the last semicolon in a block in which its braces (and therefore the content of the block) are in the same line
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint semi: ["error", "always"]*/
var name = "ESLint"
object.method = function() {
// ...
}
Examples of correct code for this rule with the default "always"
option:
/*eslint semi: "error"*/
var name = "ESLint";
object.method = function() {
// ...
};
never
Examples of incorrect code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint";
object.method = function() {
// ...
};
Examples of correct code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint"
object.method = function() {
// ...
}
var name = "ESLint"
;(function() {
// ...
})()
omitLastInOneLineBlock
Examples of additional correct code for this rule with the "always", { "omitLastInOneLineBlock": true }
options:
/*eslint semi: ["error", "always", { "omitLastInOneLineBlock": true}] */
if (foo) { bar() }
if (foo) { bar(); baz() }
When Not To Use It
If you do not want to enforce semicolon usage (or omission) in any particular way, then you can turn this rule off.
Further Reading
Related Rules
- [no-extra-semi](no-extra-semi.md)
- [no-unexpected-multiline](no-unexpected-multiline.md)
- [semi-spacing](semi-spacing.md) Source: http://eslint.org/docs/rules/
Missing JSDoc for parameter 'db'. Open
/**
- Read upRead up
- Exclude checks
enforce valid JSDoc comments (valid-jsdoc)
JSDoc generates application programming interface (API) documentation from specially-formatted comments in JavaScript code. For example, this is a JSDoc comment for a function:
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
If comments are invalid because of typing mistakes, then documentation will be incomplete.
If comments are inconsistent because they are not updated when function definitions are modified, then readers might become confused.
Rule Details
This rule enforces valid and consistent JSDoc comments. It reports any of the following problems:
- missing parameter tag:
@arg
,@argument
, or@param
- inconsistent order of parameter names in a comment compared to the function or method
- missing return tag:
@return
or@returns
- missing parameter or return type
- missing parameter or return description
- syntax error
This rule does not report missing JSDoc comments for classes, functions, or methods.
Note: This rule does not support all of the Google Closure documentation tool's use cases. As such, some code such as (/**number*/ n => n * 2);
will be flagged as missing appropriate function JSDoc comments even though /**number*/
is intended to be a type hint and not a documentation block for the function. We don't recommend using this rule if you use type hints in this way.
Examples of incorrect code for this rule:
/*eslint valid-jsdoc: "error"*/
// expected @param tag for parameter num1 but found num instead
// missing @param tag for parameter num2
// missing return type
/**
* Add two numbers.
* @param {number} num The first number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// missing brace
// missing @returns tag
/**
* @param {string name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
// missing parameter type for num1
// missing parameter description for num2
/**
* Represents a sum.
* @constructor
* @param num1 The first number.
* @param {number} num2
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
Examples of correct code for this rule:
/*eslint valid-jsdoc: "error"*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// default options allow missing function description
// return type `void` means the function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
// @constructor tag allows missing @returns tag
/**
* Represents a sum.
* @constructor
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
// class constructor allows missing @returns tag
/**
* Represents a sum.
*/
class Sum {
/**
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
constructor(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
}
// @abstract tag allows @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
// @override tag allows missing @param and @returns tags
class WonderfulWidget extends Widget {
/**
* @override
*/
mustRender (state) {
return state !== this.state; // shallow comparison
}
}
Options
This rule has an object option:
-
"prefer"
enforces consistent documentation tags specified by an object whose properties mean instead of key use value (for example,"return": "returns"
means instead of@return
use@returns
) -
"preferType"
enforces consistent type strings specified by an object whose properties mean instead of key use value (for example,"object": "Object"
means instead ofobject
useObject
) -
"requireReturn"
requires a return tag:-
true
(default) even if the function or method does not have areturn
statement (this option value does not apply to constructors) -
false
if and only if the function or method has areturn
statement (this option value does apply to constructors)
-
-
"requireReturnType": false
allows missing type in return tags -
"matchDescription"
specifies (as a string) a regular expression to match the description in each JSDoc comment (for example,".+"
requires a description; this option does not apply to descriptions in parameter or return tags) -
"requireParamDescription": false
allows missing description in parameter tags -
"requireReturnDescription": false
allows missing description in return tags
prefer
Examples of additional incorrect code for this rule with sample "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" }
options:
/*eslint valid-jsdoc: ["error", { "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @arg {int} num1 The first number.
* @arg {int} num2 The second number.
* @return {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Represents a sum.
* @class
* @argument {number} num1 The first number.
* @argument {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @virtual
* @argument {Object} state The new state of the widget.
* @return {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
preferType
Examples of additional incorrect code for this rule with sample "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" }
options:
/*eslint valid-jsdoc: ["error", { "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {Number} num1 The first number.
* @param {Number} num2 The second number.
* @returns {Number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Output a greeting as a side effect.
* @param {String} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {object} state The new state of the widget.
* @returns {Boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
requireReturn
Examples of additional incorrect code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
// unexpected @returns tag because function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {string} The greeting.
*/
function greet(name) {
console.log("Hello " + name);
}
// add @abstract tag to allow @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
Example of additional correct code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
/**
* @param {string} name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
requireReturnType
Example of additional correct code for this rule with the "requireReturnType": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnType": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
matchDescription
Example of additional incorrect code for this rule with a sample "matchDescription": ".+"
option:
/*eslint valid-jsdoc: ["error", { "matchDescription": ".+" }]*/
// missing function description
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
requireParamDescription
Example of additional correct code for this rule with the "requireParamDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireParamDescription": false }]*/
/**
* Add two numbers.
* @param {int} num1
* @param {int} num2
* @returns {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
requireReturnDescription
Example of additional correct code for this rule with the "requireReturnDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnDescription": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number}
*/
function add(num1, num2) {
return num1 + num2;
}
When Not To Use It
If you aren't using JSDoc, then you can safely turn this rule off.
Further Reading
Related Rules
- [require-jsdoc](require-jsdoc.md) Source: http://eslint.org/docs/rules/
Missing JSDoc for parameter 'db'. Open
/**
- Read upRead up
- Exclude checks
enforce valid JSDoc comments (valid-jsdoc)
JSDoc generates application programming interface (API) documentation from specially-formatted comments in JavaScript code. For example, this is a JSDoc comment for a function:
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
If comments are invalid because of typing mistakes, then documentation will be incomplete.
If comments are inconsistent because they are not updated when function definitions are modified, then readers might become confused.
Rule Details
This rule enforces valid and consistent JSDoc comments. It reports any of the following problems:
- missing parameter tag:
@arg
,@argument
, or@param
- inconsistent order of parameter names in a comment compared to the function or method
- missing return tag:
@return
or@returns
- missing parameter or return type
- missing parameter or return description
- syntax error
This rule does not report missing JSDoc comments for classes, functions, or methods.
Note: This rule does not support all of the Google Closure documentation tool's use cases. As such, some code such as (/**number*/ n => n * 2);
will be flagged as missing appropriate function JSDoc comments even though /**number*/
is intended to be a type hint and not a documentation block for the function. We don't recommend using this rule if you use type hints in this way.
Examples of incorrect code for this rule:
/*eslint valid-jsdoc: "error"*/
// expected @param tag for parameter num1 but found num instead
// missing @param tag for parameter num2
// missing return type
/**
* Add two numbers.
* @param {number} num The first number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// missing brace
// missing @returns tag
/**
* @param {string name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
// missing parameter type for num1
// missing parameter description for num2
/**
* Represents a sum.
* @constructor
* @param num1 The first number.
* @param {number} num2
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
Examples of correct code for this rule:
/*eslint valid-jsdoc: "error"*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// default options allow missing function description
// return type `void` means the function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
// @constructor tag allows missing @returns tag
/**
* Represents a sum.
* @constructor
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
// class constructor allows missing @returns tag
/**
* Represents a sum.
*/
class Sum {
/**
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
constructor(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
}
// @abstract tag allows @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
// @override tag allows missing @param and @returns tags
class WonderfulWidget extends Widget {
/**
* @override
*/
mustRender (state) {
return state !== this.state; // shallow comparison
}
}
Options
This rule has an object option:
-
"prefer"
enforces consistent documentation tags specified by an object whose properties mean instead of key use value (for example,"return": "returns"
means instead of@return
use@returns
) -
"preferType"
enforces consistent type strings specified by an object whose properties mean instead of key use value (for example,"object": "Object"
means instead ofobject
useObject
) -
"requireReturn"
requires a return tag:-
true
(default) even if the function or method does not have areturn
statement (this option value does not apply to constructors) -
false
if and only if the function or method has areturn
statement (this option value does apply to constructors)
-
-
"requireReturnType": false
allows missing type in return tags -
"matchDescription"
specifies (as a string) a regular expression to match the description in each JSDoc comment (for example,".+"
requires a description; this option does not apply to descriptions in parameter or return tags) -
"requireParamDescription": false
allows missing description in parameter tags -
"requireReturnDescription": false
allows missing description in return tags
prefer
Examples of additional incorrect code for this rule with sample "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" }
options:
/*eslint valid-jsdoc: ["error", { "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @arg {int} num1 The first number.
* @arg {int} num2 The second number.
* @return {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Represents a sum.
* @class
* @argument {number} num1 The first number.
* @argument {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @virtual
* @argument {Object} state The new state of the widget.
* @return {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
preferType
Examples of additional incorrect code for this rule with sample "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" }
options:
/*eslint valid-jsdoc: ["error", { "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {Number} num1 The first number.
* @param {Number} num2 The second number.
* @returns {Number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Output a greeting as a side effect.
* @param {String} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {object} state The new state of the widget.
* @returns {Boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
requireReturn
Examples of additional incorrect code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
// unexpected @returns tag because function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {string} The greeting.
*/
function greet(name) {
console.log("Hello " + name);
}
// add @abstract tag to allow @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
Example of additional correct code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
/**
* @param {string} name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
requireReturnType
Example of additional correct code for this rule with the "requireReturnType": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnType": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
matchDescription
Example of additional incorrect code for this rule with a sample "matchDescription": ".+"
option:
/*eslint valid-jsdoc: ["error", { "matchDescription": ".+" }]*/
// missing function description
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
requireParamDescription
Example of additional correct code for this rule with the "requireParamDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireParamDescription": false }]*/
/**
* Add two numbers.
* @param {int} num1
* @param {int} num2
* @returns {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
requireReturnDescription
Example of additional correct code for this rule with the "requireReturnDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnDescription": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number}
*/
function add(num1, num2) {
return num1 + num2;
}
When Not To Use It
If you aren't using JSDoc, then you can safely turn this rule off.
Further Reading
Related Rules
- [require-jsdoc](require-jsdoc.md) Source: http://eslint.org/docs/rules/
Missing JSDoc for parameter 'db'. Open
/**
- Read upRead up
- Exclude checks
enforce valid JSDoc comments (valid-jsdoc)
JSDoc generates application programming interface (API) documentation from specially-formatted comments in JavaScript code. For example, this is a JSDoc comment for a function:
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
If comments are invalid because of typing mistakes, then documentation will be incomplete.
If comments are inconsistent because they are not updated when function definitions are modified, then readers might become confused.
Rule Details
This rule enforces valid and consistent JSDoc comments. It reports any of the following problems:
- missing parameter tag:
@arg
,@argument
, or@param
- inconsistent order of parameter names in a comment compared to the function or method
- missing return tag:
@return
or@returns
- missing parameter or return type
- missing parameter or return description
- syntax error
This rule does not report missing JSDoc comments for classes, functions, or methods.
Note: This rule does not support all of the Google Closure documentation tool's use cases. As such, some code such as (/**number*/ n => n * 2);
will be flagged as missing appropriate function JSDoc comments even though /**number*/
is intended to be a type hint and not a documentation block for the function. We don't recommend using this rule if you use type hints in this way.
Examples of incorrect code for this rule:
/*eslint valid-jsdoc: "error"*/
// expected @param tag for parameter num1 but found num instead
// missing @param tag for parameter num2
// missing return type
/**
* Add two numbers.
* @param {number} num The first number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// missing brace
// missing @returns tag
/**
* @param {string name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
// missing parameter type for num1
// missing parameter description for num2
/**
* Represents a sum.
* @constructor
* @param num1 The first number.
* @param {number} num2
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
Examples of correct code for this rule:
/*eslint valid-jsdoc: "error"*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// default options allow missing function description
// return type `void` means the function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
// @constructor tag allows missing @returns tag
/**
* Represents a sum.
* @constructor
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
// class constructor allows missing @returns tag
/**
* Represents a sum.
*/
class Sum {
/**
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
constructor(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
}
// @abstract tag allows @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
// @override tag allows missing @param and @returns tags
class WonderfulWidget extends Widget {
/**
* @override
*/
mustRender (state) {
return state !== this.state; // shallow comparison
}
}
Options
This rule has an object option:
-
"prefer"
enforces consistent documentation tags specified by an object whose properties mean instead of key use value (for example,"return": "returns"
means instead of@return
use@returns
) -
"preferType"
enforces consistent type strings specified by an object whose properties mean instead of key use value (for example,"object": "Object"
means instead ofobject
useObject
) -
"requireReturn"
requires a return tag:-
true
(default) even if the function or method does not have areturn
statement (this option value does not apply to constructors) -
false
if and only if the function or method has areturn
statement (this option value does apply to constructors)
-
-
"requireReturnType": false
allows missing type in return tags -
"matchDescription"
specifies (as a string) a regular expression to match the description in each JSDoc comment (for example,".+"
requires a description; this option does not apply to descriptions in parameter or return tags) -
"requireParamDescription": false
allows missing description in parameter tags -
"requireReturnDescription": false
allows missing description in return tags
prefer
Examples of additional incorrect code for this rule with sample "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" }
options:
/*eslint valid-jsdoc: ["error", { "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @arg {int} num1 The first number.
* @arg {int} num2 The second number.
* @return {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Represents a sum.
* @class
* @argument {number} num1 The first number.
* @argument {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @virtual
* @argument {Object} state The new state of the widget.
* @return {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
preferType
Examples of additional incorrect code for this rule with sample "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" }
options:
/*eslint valid-jsdoc: ["error", { "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {Number} num1 The first number.
* @param {Number} num2 The second number.
* @returns {Number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Output a greeting as a side effect.
* @param {String} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {object} state The new state of the widget.
* @returns {Boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
requireReturn
Examples of additional incorrect code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
// unexpected @returns tag because function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {string} The greeting.
*/
function greet(name) {
console.log("Hello " + name);
}
// add @abstract tag to allow @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
Example of additional correct code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
/**
* @param {string} name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
requireReturnType
Example of additional correct code for this rule with the "requireReturnType": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnType": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
matchDescription
Example of additional incorrect code for this rule with a sample "matchDescription": ".+"
option:
/*eslint valid-jsdoc: ["error", { "matchDescription": ".+" }]*/
// missing function description
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
requireParamDescription
Example of additional correct code for this rule with the "requireParamDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireParamDescription": false }]*/
/**
* Add two numbers.
* @param {int} num1
* @param {int} num2
* @returns {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
requireReturnDescription
Example of additional correct code for this rule with the "requireReturnDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnDescription": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number}
*/
function add(num1, num2) {
return num1 + num2;
}
When Not To Use It
If you aren't using JSDoc, then you can safely turn this rule off.
Further Reading
Related Rules
- [require-jsdoc](require-jsdoc.md) Source: http://eslint.org/docs/rules/
Missing JSDoc for parameter 'db'. Open
/**
- Read upRead up
- Exclude checks
enforce valid JSDoc comments (valid-jsdoc)
JSDoc generates application programming interface (API) documentation from specially-formatted comments in JavaScript code. For example, this is a JSDoc comment for a function:
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
If comments are invalid because of typing mistakes, then documentation will be incomplete.
If comments are inconsistent because they are not updated when function definitions are modified, then readers might become confused.
Rule Details
This rule enforces valid and consistent JSDoc comments. It reports any of the following problems:
- missing parameter tag:
@arg
,@argument
, or@param
- inconsistent order of parameter names in a comment compared to the function or method
- missing return tag:
@return
or@returns
- missing parameter or return type
- missing parameter or return description
- syntax error
This rule does not report missing JSDoc comments for classes, functions, or methods.
Note: This rule does not support all of the Google Closure documentation tool's use cases. As such, some code such as (/**number*/ n => n * 2);
will be flagged as missing appropriate function JSDoc comments even though /**number*/
is intended to be a type hint and not a documentation block for the function. We don't recommend using this rule if you use type hints in this way.
Examples of incorrect code for this rule:
/*eslint valid-jsdoc: "error"*/
// expected @param tag for parameter num1 but found num instead
// missing @param tag for parameter num2
// missing return type
/**
* Add two numbers.
* @param {number} num The first number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// missing brace
// missing @returns tag
/**
* @param {string name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
// missing parameter type for num1
// missing parameter description for num2
/**
* Represents a sum.
* @constructor
* @param num1 The first number.
* @param {number} num2
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
Examples of correct code for this rule:
/*eslint valid-jsdoc: "error"*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// default options allow missing function description
// return type `void` means the function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
// @constructor tag allows missing @returns tag
/**
* Represents a sum.
* @constructor
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
// class constructor allows missing @returns tag
/**
* Represents a sum.
*/
class Sum {
/**
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
constructor(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
}
// @abstract tag allows @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
// @override tag allows missing @param and @returns tags
class WonderfulWidget extends Widget {
/**
* @override
*/
mustRender (state) {
return state !== this.state; // shallow comparison
}
}
Options
This rule has an object option:
-
"prefer"
enforces consistent documentation tags specified by an object whose properties mean instead of key use value (for example,"return": "returns"
means instead of@return
use@returns
) -
"preferType"
enforces consistent type strings specified by an object whose properties mean instead of key use value (for example,"object": "Object"
means instead ofobject
useObject
) -
"requireReturn"
requires a return tag:-
true
(default) even if the function or method does not have areturn
statement (this option value does not apply to constructors) -
false
if and only if the function or method has areturn
statement (this option value does apply to constructors)
-
-
"requireReturnType": false
allows missing type in return tags -
"matchDescription"
specifies (as a string) a regular expression to match the description in each JSDoc comment (for example,".+"
requires a description; this option does not apply to descriptions in parameter or return tags) -
"requireParamDescription": false
allows missing description in parameter tags -
"requireReturnDescription": false
allows missing description in return tags
prefer
Examples of additional incorrect code for this rule with sample "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" }
options:
/*eslint valid-jsdoc: ["error", { "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @arg {int} num1 The first number.
* @arg {int} num2 The second number.
* @return {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Represents a sum.
* @class
* @argument {number} num1 The first number.
* @argument {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @virtual
* @argument {Object} state The new state of the widget.
* @return {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
preferType
Examples of additional incorrect code for this rule with sample "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" }
options:
/*eslint valid-jsdoc: ["error", { "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {Number} num1 The first number.
* @param {Number} num2 The second number.
* @returns {Number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Output a greeting as a side effect.
* @param {String} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {object} state The new state of the widget.
* @returns {Boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
requireReturn
Examples of additional incorrect code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
// unexpected @returns tag because function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {string} The greeting.
*/
function greet(name) {
console.log("Hello " + name);
}
// add @abstract tag to allow @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
Example of additional correct code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
/**
* @param {string} name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
requireReturnType
Example of additional correct code for this rule with the "requireReturnType": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnType": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
matchDescription
Example of additional incorrect code for this rule with a sample "matchDescription": ".+"
option:
/*eslint valid-jsdoc: ["error", { "matchDescription": ".+" }]*/
// missing function description
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
requireParamDescription
Example of additional correct code for this rule with the "requireParamDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireParamDescription": false }]*/
/**
* Add two numbers.
* @param {int} num1
* @param {int} num2
* @returns {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
requireReturnDescription
Example of additional correct code for this rule with the "requireReturnDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnDescription": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number}
*/
function add(num1, num2) {
return num1 + num2;
}
When Not To Use It
If you aren't using JSDoc, then you can safely turn this rule off.
Further Reading
Related Rules
- [require-jsdoc](require-jsdoc.md) Source: http://eslint.org/docs/rules/
Missing JSDoc for parameter 'db'. Open
/**
- Read upRead up
- Exclude checks
enforce valid JSDoc comments (valid-jsdoc)
JSDoc generates application programming interface (API) documentation from specially-formatted comments in JavaScript code. For example, this is a JSDoc comment for a function:
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
If comments are invalid because of typing mistakes, then documentation will be incomplete.
If comments are inconsistent because they are not updated when function definitions are modified, then readers might become confused.
Rule Details
This rule enforces valid and consistent JSDoc comments. It reports any of the following problems:
- missing parameter tag:
@arg
,@argument
, or@param
- inconsistent order of parameter names in a comment compared to the function or method
- missing return tag:
@return
or@returns
- missing parameter or return type
- missing parameter or return description
- syntax error
This rule does not report missing JSDoc comments for classes, functions, or methods.
Note: This rule does not support all of the Google Closure documentation tool's use cases. As such, some code such as (/**number*/ n => n * 2);
will be flagged as missing appropriate function JSDoc comments even though /**number*/
is intended to be a type hint and not a documentation block for the function. We don't recommend using this rule if you use type hints in this way.
Examples of incorrect code for this rule:
/*eslint valid-jsdoc: "error"*/
// expected @param tag for parameter num1 but found num instead
// missing @param tag for parameter num2
// missing return type
/**
* Add two numbers.
* @param {number} num The first number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// missing brace
// missing @returns tag
/**
* @param {string name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
// missing parameter type for num1
// missing parameter description for num2
/**
* Represents a sum.
* @constructor
* @param num1 The first number.
* @param {number} num2
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
Examples of correct code for this rule:
/*eslint valid-jsdoc: "error"*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
// default options allow missing function description
// return type `void` means the function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
// @constructor tag allows missing @returns tag
/**
* Represents a sum.
* @constructor
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
// class constructor allows missing @returns tag
/**
* Represents a sum.
*/
class Sum {
/**
* @param {number} num1 The first number.
* @param {number} num2 The second number.
*/
constructor(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
}
// @abstract tag allows @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
// @override tag allows missing @param and @returns tags
class WonderfulWidget extends Widget {
/**
* @override
*/
mustRender (state) {
return state !== this.state; // shallow comparison
}
}
Options
This rule has an object option:
-
"prefer"
enforces consistent documentation tags specified by an object whose properties mean instead of key use value (for example,"return": "returns"
means instead of@return
use@returns
) -
"preferType"
enforces consistent type strings specified by an object whose properties mean instead of key use value (for example,"object": "Object"
means instead ofobject
useObject
) -
"requireReturn"
requires a return tag:-
true
(default) even if the function or method does not have areturn
statement (this option value does not apply to constructors) -
false
if and only if the function or method has areturn
statement (this option value does apply to constructors)
-
-
"requireReturnType": false
allows missing type in return tags -
"matchDescription"
specifies (as a string) a regular expression to match the description in each JSDoc comment (for example,".+"
requires a description; this option does not apply to descriptions in parameter or return tags) -
"requireParamDescription": false
allows missing description in parameter tags -
"requireReturnDescription": false
allows missing description in return tags
prefer
Examples of additional incorrect code for this rule with sample "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" }
options:
/*eslint valid-jsdoc: ["error", { "prefer": { "arg": "param", "argument": "param", "class": "constructor", "return": "returns", "virtual": "abstract" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @arg {int} num1 The first number.
* @arg {int} num2 The second number.
* @return {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Represents a sum.
* @class
* @argument {number} num1 The first number.
* @argument {number} num2 The second number.
*/
function sum(num1, num2) {
this.num1 = num1;
this.num2 = num2;
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @virtual
* @argument {Object} state The new state of the widget.
* @return {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
preferType
Examples of additional incorrect code for this rule with sample "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" }
options:
/*eslint valid-jsdoc: ["error", { "preferType": { "Boolean": "boolean", "Number": "number", "object": "Object", "String": "string" } }]*/
/*eslint-env es6*/
/**
* Add two numbers.
* @param {Number} num1 The first number.
* @param {Number} num2 The second number.
* @returns {Number} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
/**
* Output a greeting as a side effect.
* @param {String} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @abstract
* @param {object} state The new state of the widget.
* @returns {Boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
requireReturn
Examples of additional incorrect code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
// unexpected @returns tag because function has no `return` statement
/**
* @param {string} name Whom to greet.
* @returns {string} The greeting.
*/
function greet(name) {
console.log("Hello " + name);
}
// add @abstract tag to allow @returns tag without `return` statement
class Widget {
/**
* When the state changes, does it affect the rendered appearance?
* @param {Object} state The new state of the widget.
* @returns {boolean} Is current appearance inconsistent with new state?
*/
mustRender (state) {
throw new Error("Widget subclass did not implement mustRender");
}
}
Example of additional correct code for this rule with the "requireReturn": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturn": false }]*/
/**
* @param {string} name Whom to greet.
*/
function greet(name) {
console.log("Hello " + name);
}
requireReturnType
Example of additional correct code for this rule with the "requireReturnType": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnType": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
matchDescription
Example of additional incorrect code for this rule with a sample "matchDescription": ".+"
option:
/*eslint valid-jsdoc: ["error", { "matchDescription": ".+" }]*/
// missing function description
/**
* @param {string} name Whom to greet.
* @returns {void}
*/
function greet(name) {
console.log("Hello " + name);
}
requireParamDescription
Example of additional correct code for this rule with the "requireParamDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireParamDescription": false }]*/
/**
* Add two numbers.
* @param {int} num1
* @param {int} num2
* @returns {int} The sum of the two numbers.
*/
function add(num1, num2) {
return num1 + num2;
}
requireReturnDescription
Example of additional correct code for this rule with the "requireReturnDescription": false
option:
/*eslint valid-jsdoc: ["error", { "requireReturnDescription": false }]*/
/**
* Add two numbers.
* @param {number} num1 The first number.
* @param {number} num2 The second number.
* @returns {number}
*/
function add(num1, num2) {
return num1 + num2;
}
When Not To Use It
If you aren't using JSDoc, then you can safely turn this rule off.
Further Reading
Related Rules
- [require-jsdoc](require-jsdoc.md) Source: http://eslint.org/docs/rules/