Function generateCommandDocumentation
has a Cognitive Complexity of 27 (exceeds 5 allowed). Consider refactoring. Open
export default function generateCommandDocumentation(settings, metaSettings, metaCommands, command, name, parents) {
const rows = [];
rows.push(`Usage: ${name} ${parents.concat(command).join(' ')}` +
getCommandArgumentsAsString(metaCommands[command]));
rows.push('');
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Function generateCommandDocumentation
has 89 lines of code (exceeds 25 allowed). Consider refactoring. Open
export default function generateCommandDocumentation(settings, metaSettings, metaCommands, command, name, parents) {
const rows = [];
rows.push(`Usage: ${name} ${parents.concat(command).join(' ')}` +
getCommandArgumentsAsString(metaCommands[command]));
rows.push('');
Function generateCommandDocumentation
has 6 arguments (exceeds 4 allowed). Consider refactoring. Open
export default function generateCommandDocumentation(settings, metaSettings, metaCommands, command, name, parents) {
Function createDescription
has a Cognitive Complexity of 7 (exceeds 5 allowed). Consider refactoring. Open
function createDescription(param) {
const infoObject = getInfoObject(param.validator);
return `${(param.description && param.description + ' ') || ''}` +
`${(infoObject.required && green('Required') + ' ') || ''}` +
`${(param.default !== undefined && cyan(JSON.stringify(param.default)) + ' ') || ''}` +
- Read upRead up
Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Unexpected parentheses around single function argument having a body with no curly braces Open
const objects = objectToArray(metaCommands[command].options).sort(onProperty('name')).map((option) => (
- Read upRead up
- Exclude checks
Require parens in arrow function arguments (arrow-parens)
Arrow functions can omit parentheses when they have exactly one parameter. In all other cases the parameter(s) must be wrapped in parentheses. This rule enforces the consistent use of parentheses in arrow functions.
Rule Details
This rule enforces parentheses around arrow function parameters regardless of arity. For example:
/*eslint-env es6*/
// Bad
a => {}
// Good
(a) => {}
Following this style will help you find arrow functions (=>
) which may be mistakenly included in a condition
when a comparison such as >=
was the intent.
/*eslint-env es6*/
// Bad
if (a => 2) {
}
// Good
if (a >= 2) {
}
The rule can also be configured to discourage the use of parens when they are not required:
/*eslint-env es6*/
// Bad
(a) => {}
// Good
a => {}
Options
This rule has a string option and an object one.
String options are:
-
"always"
(default) requires parens around arguments in all cases. -
"as-needed"
allows omitting parens when there is only one argument.
Object properties for variants of the "as-needed"
option:
-
"requireForBlockBody": true
modifies the as-needed rule in order to require parens if the function body is in an instructions block (surrounded by braces).
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint arrow-parens: ["error", "always"]*/
/*eslint-env es6*/
a => {};
a => a;
a => {'\n'};
a.then(foo => {});
a.then(foo => a);
a(foo => { if (true) {} });
Examples of correct code for this rule with the default "always"
option:
/*eslint arrow-parens: ["error", "always"]*/
/*eslint-env es6*/
() => {};
(a) => {};
(a) => a;
(a) => {'\n'}
a.then((foo) => {});
a.then((foo) => { if (true) {} });
If Statements
One of benefits of this option is that it prevents the incorrect use of arrow functions in conditionals:
/*eslint-env es6*/
var a = 1;
var b = 2;
// ...
if (a => b) {
console.log('bigger');
} else {
console.log('smaller');
}
// outputs 'bigger', not smaller as expected
The contents of the if
statement is an arrow function, not a comparison.
If the arrow function is intentional, it should be wrapped in parens to remove ambiguity.
/*eslint-env es6*/
var a = 1;
var b = 0;
// ...
if ((a) => b) {
console.log('truthy value returned');
} else {
console.log('falsey value returned');
}
// outputs 'truthy value returned'
The following is another example of this behavior:
/*eslint-env es6*/
var a = 1, b = 2, c = 3, d = 4;
var f = a => b ? c: d;
// f = ?
f
is an arrow function which takes a
as an argument and returns the result of b ? c: d
.
This should be rewritten like so:
/*eslint-env es6*/
var a = 1, b = 2, c = 3, d = 4;
var f = (a) => b ? c: d;
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint arrow-parens: ["error", "as-needed"]*/
/*eslint-env es6*/
(a) => {};
(a) => a;
(a) => {'\n'};
a.then((foo) => {});
a.then((foo) => a);
a((foo) => { if (true) {} });
Examples of correct code for this rule with the "as-needed"
option:
/*eslint arrow-parens: ["error", "as-needed"]*/
/*eslint-env es6*/
() => {};
a => {};
a => a;
a => {'\n'};
a.then(foo => {});
a.then(foo => { if (true) {} });
(a, b, c) => a;
(a = 10) => a;
([a, b]) => a;
({a, b}) => a;
requireForBlockBody
Examples of incorrect code for the { "requireForBlockBody": true }
option:
/*eslint arrow-parens: [2, "as-needed", { "requireForBlockBody": true }]*/
/*eslint-env es6*/
(a) => a;
a => {};
a => {'\n'};
a.map((x) => x * x);
a.map(x => {
return x * x;
});
a.then(foo => {});
Examples of correct code for the { "requireForBlockBody": true }
option:
/*eslint arrow-parens: [2, "as-needed", { "requireForBlockBody": true }]*/
/*eslint-env es6*/
(a) => {};
(a) => {'\n'};
a => ({});
() => {};
a => a;
a.then((foo) => {});
a.then((foo) => { if (true) {} });
a((foo) => { if (true) {} });
(a, b, c) => a;
(a = 10) => a;
([a, b]) => a;
({a, b}) => a;
Further Reading
- The
"as-needed", { "requireForBlockBody": true }
rule is directly inspired by the Airbnb JS Style Guide. Source: http://eslint.org/docs/rules/
Unexpected string concatenation. Open
rows.push(`Usage: ${name} ${parents.concat(command).join(' ')}` +
- Read upRead up
- Exclude checks
Suggest using template literals instead of string concatenation. (prefer-template)
In ES2015 (ES6), we can use template literals instead of string concatenation.
var str = "Hello, " + name + "!";
/*eslint-env es6*/
var str = `Hello, ${name}!`;
Rule Details
This rule is aimed to flag usage of +
operators with strings.
Examples
Examples of incorrect code for this rule:
/*eslint prefer-template: "error"*/
var str = "Hello, " + name + "!";
var str = "Time: " + (12 * 60 * 60 * 1000);
Examples of correct code for this rule:
/*eslint prefer-template: "error"*/
/*eslint-env es6*/
var str = "Hello World!";
var str = `Hello, ${name}!`;
var str = `Time: ${12 * 60 * 60 * 1000}`;
// This is reported by `no-useless-concat`.
var str = "Hello, " + "World!";
When Not To Use It
This rule should not be used in ES3/5 environments.
In ES2015 (ES6) or later, if you don't want to be notified about string concatenation, you can safely disable this rule.
Related Rules
- [no-useless-concat](no-useless-concat.md)
- [quotes](quotes.md) Source: http://eslint.org/docs/rules/
Unexpected parentheses around single function argument having a body with no curly braces Open
const objects = objectToArray(metaCommands[command].arguments).map((argument) => (
- Read upRead up
- Exclude checks
Require parens in arrow function arguments (arrow-parens)
Arrow functions can omit parentheses when they have exactly one parameter. In all other cases the parameter(s) must be wrapped in parentheses. This rule enforces the consistent use of parentheses in arrow functions.
Rule Details
This rule enforces parentheses around arrow function parameters regardless of arity. For example:
/*eslint-env es6*/
// Bad
a => {}
// Good
(a) => {}
Following this style will help you find arrow functions (=>
) which may be mistakenly included in a condition
when a comparison such as >=
was the intent.
/*eslint-env es6*/
// Bad
if (a => 2) {
}
// Good
if (a >= 2) {
}
The rule can also be configured to discourage the use of parens when they are not required:
/*eslint-env es6*/
// Bad
(a) => {}
// Good
a => {}
Options
This rule has a string option and an object one.
String options are:
-
"always"
(default) requires parens around arguments in all cases. -
"as-needed"
allows omitting parens when there is only one argument.
Object properties for variants of the "as-needed"
option:
-
"requireForBlockBody": true
modifies the as-needed rule in order to require parens if the function body is in an instructions block (surrounded by braces).
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint arrow-parens: ["error", "always"]*/
/*eslint-env es6*/
a => {};
a => a;
a => {'\n'};
a.then(foo => {});
a.then(foo => a);
a(foo => { if (true) {} });
Examples of correct code for this rule with the default "always"
option:
/*eslint arrow-parens: ["error", "always"]*/
/*eslint-env es6*/
() => {};
(a) => {};
(a) => a;
(a) => {'\n'}
a.then((foo) => {});
a.then((foo) => { if (true) {} });
If Statements
One of benefits of this option is that it prevents the incorrect use of arrow functions in conditionals:
/*eslint-env es6*/
var a = 1;
var b = 2;
// ...
if (a => b) {
console.log('bigger');
} else {
console.log('smaller');
}
// outputs 'bigger', not smaller as expected
The contents of the if
statement is an arrow function, not a comparison.
If the arrow function is intentional, it should be wrapped in parens to remove ambiguity.
/*eslint-env es6*/
var a = 1;
var b = 0;
// ...
if ((a) => b) {
console.log('truthy value returned');
} else {
console.log('falsey value returned');
}
// outputs 'truthy value returned'
The following is another example of this behavior:
/*eslint-env es6*/
var a = 1, b = 2, c = 3, d = 4;
var f = a => b ? c: d;
// f = ?
f
is an arrow function which takes a
as an argument and returns the result of b ? c: d
.
This should be rewritten like so:
/*eslint-env es6*/
var a = 1, b = 2, c = 3, d = 4;
var f = (a) => b ? c: d;
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint arrow-parens: ["error", "as-needed"]*/
/*eslint-env es6*/
(a) => {};
(a) => a;
(a) => {'\n'};
a.then((foo) => {});
a.then((foo) => a);
a((foo) => { if (true) {} });
Examples of correct code for this rule with the "as-needed"
option:
/*eslint arrow-parens: ["error", "as-needed"]*/
/*eslint-env es6*/
() => {};
a => {};
a => a;
a => {'\n'};
a.then(foo => {});
a.then(foo => { if (true) {} });
(a, b, c) => a;
(a = 10) => a;
([a, b]) => a;
({a, b}) => a;
requireForBlockBody
Examples of incorrect code for the { "requireForBlockBody": true }
option:
/*eslint arrow-parens: [2, "as-needed", { "requireForBlockBody": true }]*/
/*eslint-env es6*/
(a) => a;
a => {};
a => {'\n'};
a.map((x) => x * x);
a.map(x => {
return x * x;
});
a.then(foo => {});
Examples of correct code for the { "requireForBlockBody": true }
option:
/*eslint arrow-parens: [2, "as-needed", { "requireForBlockBody": true }]*/
/*eslint-env es6*/
(a) => {};
(a) => {'\n'};
a => ({});
() => {};
a => a;
a.then((foo) => {});
a.then((foo) => { if (true) {} });
a((foo) => { if (true) {} });
(a, b, c) => a;
(a = 10) => a;
([a, b]) => a;
({a, b}) => a;
Further Reading
- The
"as-needed", { "requireForBlockBody": true }
rule is directly inspired by the Airbnb JS Style Guide. Source: http://eslint.org/docs/rules/
Unexpected string concatenation. Open
`${(param.default !== undefined && cyan(JSON.stringify(param.default)) + ' ') || ''}` +
- Read upRead up
- Exclude checks
Suggest using template literals instead of string concatenation. (prefer-template)
In ES2015 (ES6), we can use template literals instead of string concatenation.
var str = "Hello, " + name + "!";
/*eslint-env es6*/
var str = `Hello, ${name}!`;
Rule Details
This rule is aimed to flag usage of +
operators with strings.
Examples
Examples of incorrect code for this rule:
/*eslint prefer-template: "error"*/
var str = "Hello, " + name + "!";
var str = "Time: " + (12 * 60 * 60 * 1000);
Examples of correct code for this rule:
/*eslint prefer-template: "error"*/
/*eslint-env es6*/
var str = "Hello World!";
var str = `Hello, ${name}!`;
var str = `Time: ${12 * 60 * 60 * 1000}`;
// This is reported by `no-useless-concat`.
var str = "Hello, " + "World!";
When Not To Use It
This rule should not be used in ES3/5 environments.
In ES2015 (ES6) or later, if you don't want to be notified about string concatenation, you can safely disable this rule.
Related Rules
- [no-useless-concat](no-useless-concat.md)
- [quotes](quotes.md) Source: http://eslint.org/docs/rules/
Unexpected string concatenation. Open
dim('(' + infoObject.type + ')') :
- Read upRead up
- Exclude checks
Suggest using template literals instead of string concatenation. (prefer-template)
In ES2015 (ES6), we can use template literals instead of string concatenation.
var str = "Hello, " + name + "!";
/*eslint-env es6*/
var str = `Hello, ${name}!`;
Rule Details
This rule is aimed to flag usage of +
operators with strings.
Examples
Examples of incorrect code for this rule:
/*eslint prefer-template: "error"*/
var str = "Hello, " + name + "!";
var str = "Time: " + (12 * 60 * 60 * 1000);
Examples of correct code for this rule:
/*eslint prefer-template: "error"*/
/*eslint-env es6*/
var str = "Hello World!";
var str = `Hello, ${name}!`;
var str = `Time: ${12 * 60 * 60 * 1000}`;
// This is reported by `no-useless-concat`.
var str = "Hello, " + "World!";
When Not To Use It
This rule should not be used in ES3/5 environments.
In ES2015 (ES6) or later, if you don't want to be notified about string concatenation, you can safely disable this rule.
Related Rules
- [no-useless-concat](no-useless-concat.md)
- [quotes](quotes.md) Source: http://eslint.org/docs/rules/
Unexpected string concatenation. Open
`${(infoObject.required && green('Required') + ' ') || ''}` +
- Read upRead up
- Exclude checks
Suggest using template literals instead of string concatenation. (prefer-template)
In ES2015 (ES6), we can use template literals instead of string concatenation.
var str = "Hello, " + name + "!";
/*eslint-env es6*/
var str = `Hello, ${name}!`;
Rule Details
This rule is aimed to flag usage of +
operators with strings.
Examples
Examples of incorrect code for this rule:
/*eslint prefer-template: "error"*/
var str = "Hello, " + name + "!";
var str = "Time: " + (12 * 60 * 60 * 1000);
Examples of correct code for this rule:
/*eslint prefer-template: "error"*/
/*eslint-env es6*/
var str = "Hello World!";
var str = `Hello, ${name}!`;
var str = `Time: ${12 * 60 * 60 * 1000}`;
// This is reported by `no-useless-concat`.
var str = "Hello, " + "World!";
When Not To Use It
This rule should not be used in ES3/5 environments.
In ES2015 (ES6) or later, if you don't want to be notified about string concatenation, you can safely disable this rule.
Related Rules
- [no-useless-concat](no-useless-concat.md)
- [quotes](quotes.md) Source: http://eslint.org/docs/rules/
Unexpected string concatenation. Open
return `${(param.description && param.description + ' ') || ''}` +
- Read upRead up
- Exclude checks
Suggest using template literals instead of string concatenation. (prefer-template)
In ES2015 (ES6), we can use template literals instead of string concatenation.
var str = "Hello, " + name + "!";
/*eslint-env es6*/
var str = `Hello, ${name}!`;
Rule Details
This rule is aimed to flag usage of +
operators with strings.
Examples
Examples of incorrect code for this rule:
/*eslint prefer-template: "error"*/
var str = "Hello, " + name + "!";
var str = "Time: " + (12 * 60 * 60 * 1000);
Examples of correct code for this rule:
/*eslint prefer-template: "error"*/
/*eslint-env es6*/
var str = "Hello World!";
var str = `Hello, ${name}!`;
var str = `Time: ${12 * 60 * 60 * 1000}`;
// This is reported by `no-useless-concat`.
var str = "Hello, " + "World!";
When Not To Use It
This rule should not be used in ES3/5 environments.
In ES2015 (ES6) or later, if you don't want to be notified about string concatenation, you can safely disable this rule.
Related Rules
- [no-useless-concat](no-useless-concat.md)
- [quotes](quotes.md) Source: http://eslint.org/docs/rules/
Similar blocks of code found in 2 locations. Consider refactoring. Open
cli: option.alias ? `-${option.alias}, --${option.name}` : `--${option.name}`,
- 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 49.
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
if (objects.length > 0) {
body = body.concat({
name: 'Command options',
level: 0,
objects,
- 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 46.
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