Sign upLogin

bondden/esf-puml

View on GitHub
Star

Showing 116 of 116 total issues

Unexpected space before opening brace.
Open

      customCwd: function customCwd(buf, cwd) {
Severity: Minor
Found in index.js by eslint

Require Or Disallow Space Before Blocks (space-before-blocks)

Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.

Rule Details

This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.

  • This rule ignores spacing which is between => and a block. The spacing is handled by the arrow-spacing rule.
  • This rule ignores spacing which is between a keyword and a block. The spacing is handled by the keyword-spacing rule.

Options

This rule takes one argument. If it is "always" then blocks must always have at least one preceding space. If "never" then all blocks should never have any preceding space. If different spacing is desired for function blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to configure the cases separately.

( e.g. { "functions": "never", "keywords": "always", "classes": "always" } )

The default is "always".

"always"

Examples of incorrect code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try {} catch(a){}

class Foo{
  constructor(){}
}

Examples of correct code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a) {
    b();
}

if (a) {
    b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
    c();
}


function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

"never"

Examples of incorrect code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a) {
    b();
}

function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

Examples of correct code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try{} catch(a){}

class Foo{
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

function a() {}

try {} catch(a){}

class Foo{
  constructor() {}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

for (;;) {
  // ...
}

describe(function(){
  // ...
});

class Foo {
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

function a(){}

try {} catch(a) {}

class Foo {
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

if (a){
  b();
}

var a = function() {}

class Foo{
  constructor() {}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo{
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo {
  constructor(){}
}

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing before blocks.

Related Rules

'a' is defined but never used.
Open

          m.forEach((v, i, a) => {
Severity: Minor
Found in index.js by eslint

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 or commonjs
  • when parserOptions.sourceType is module
  • when ecmaFeatures.globalReturn is true

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/

Unexpected space before opening brace.
Open

      createQryStr: function createQryStr(inpStr, outFile) {
Severity: Minor
Found in index.js by eslint

Require Or Disallow Space Before Blocks (space-before-blocks)

Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.

Rule Details

This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.

  • This rule ignores spacing which is between => and a block. The spacing is handled by the arrow-spacing rule.
  • This rule ignores spacing which is between a keyword and a block. The spacing is handled by the keyword-spacing rule.

Options

This rule takes one argument. If it is "always" then blocks must always have at least one preceding space. If "never" then all blocks should never have any preceding space. If different spacing is desired for function blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to configure the cases separately.

( e.g. { "functions": "never", "keywords": "always", "classes": "always" } )

The default is "always".

"always"

Examples of incorrect code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try {} catch(a){}

class Foo{
  constructor(){}
}

Examples of correct code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a) {
    b();
}

if (a) {
    b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
    c();
}


function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

"never"

Examples of incorrect code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a) {
    b();
}

function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

Examples of correct code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try{} catch(a){}

class Foo{
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

function a() {}

try {} catch(a){}

class Foo{
  constructor() {}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

for (;;) {
  // ...
}

describe(function(){
  // ...
});

class Foo {
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

function a(){}

try {} catch(a) {}

class Foo {
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

if (a){
  b();
}

var a = function() {}

class Foo{
  constructor() {}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo{
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo {
  constructor(){}
}

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing before blocks.

Related Rules

Unexpected space before opening brace.
Open

      createQryStm: function createQryStm() {
Severity: Minor
Found in index.js by eslint

Require Or Disallow Space Before Blocks (space-before-blocks)

Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.

Rule Details

This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.

  • This rule ignores spacing which is between => and a block. The spacing is handled by the arrow-spacing rule.
  • This rule ignores spacing which is between a keyword and a block. The spacing is handled by the keyword-spacing rule.

Options

This rule takes one argument. If it is "always" then blocks must always have at least one preceding space. If "never" then all blocks should never have any preceding space. If different spacing is desired for function blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to configure the cases separately.

( e.g. { "functions": "never", "keywords": "always", "classes": "always" } )

The default is "always".

"always"

Examples of incorrect code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try {} catch(a){}

class Foo{
  constructor(){}
}

Examples of correct code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a) {
    b();
}

if (a) {
    b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
    c();
}


function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

"never"

Examples of incorrect code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a) {
    b();
}

function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

Examples of correct code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try{} catch(a){}

class Foo{
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

function a() {}

try {} catch(a){}

class Foo{
  constructor() {}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

for (;;) {
  // ...
}

describe(function(){
  // ...
});

class Foo {
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

function a(){}

try {} catch(a) {}

class Foo {
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

if (a){
  b();
}

var a = function() {}

class Foo{
  constructor() {}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo{
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo {
  constructor(){}
}

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing before blocks.

Related Rules

'test' is not defined.
Open

    test('renderFile to png',done=>{
Severity: Minor
Found in tst/index.js by eslint

Disallow Undeclared Variables (no-undef)

This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var keyword in a for loop initializer).

Rule Details

Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/ comment.

Examples of incorrect code for this rule:

/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

Examples of correct code for this rule with global declaration:

/*global someFunction b:true*/
/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

The b:true syntax in /*global */ indicates that assignment to b is correct.

Examples of incorrect code for this rule with global declaration:

/*global b*/
/*eslint no-undef: "error"*/

b = 10;

By default, variables declared in /*global */ are read-only, therefore assignment is incorrect.

Options

  • typeof set to true will warn for variables used inside typeof check (Default false).

typeof

Examples of correct code for the default { "typeof": false } option:

/*eslint no-undef: "error"*/

if (typeof UndefinedIdentifier === "undefined") {
    // do something ...
}

You can use this option if you want to prevent typeof check on a variable which has not been declared.

Examples of incorrect code for the { "typeof": true } option:

/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Examples of correct code for the { "typeof": true } option with global declaration:

/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Environments

For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.

browser

Examples of correct code for this rule with browser environment:

/*eslint no-undef: "error"*/
/*eslint-env browser*/

setTimeout(function() {
    alert("Hello");
});

node

Examples of correct code for this rule with node environment:

/*eslint no-undef: "error"*/
/*eslint-env node*/

var fs = require("fs");
module.exports = function() {
    console.log(fs);
};

When Not To Use It

If explicit declaration of global variables is not to your taste.

Compatibility

This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/

'r' is defined but never used.
Open

      ).then((r)=>{
Severity: Minor
Found in tst/index.js by eslint

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 or commonjs
  • when parserOptions.sourceType is module
  • when ecmaFeatures.globalReturn is true

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/

'test' is not defined.
Open

    test('renderString',done=>{
Severity: Minor
Found in tst/index.js by eslint

Disallow Undeclared Variables (no-undef)

This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var keyword in a for loop initializer).

Rule Details

Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/ comment.

Examples of incorrect code for this rule:

/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

Examples of correct code for this rule with global declaration:

/*global someFunction b:true*/
/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

The b:true syntax in /*global */ indicates that assignment to b is correct.

Examples of incorrect code for this rule with global declaration:

/*global b*/
/*eslint no-undef: "error"*/

b = 10;

By default, variables declared in /*global */ are read-only, therefore assignment is incorrect.

Options

  • typeof set to true will warn for variables used inside typeof check (Default false).

typeof

Examples of correct code for the default { "typeof": false } option:

/*eslint no-undef: "error"*/

if (typeof UndefinedIdentifier === "undefined") {
    // do something ...
}

You can use this option if you want to prevent typeof check on a variable which has not been declared.

Examples of incorrect code for the { "typeof": true } option:

/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Examples of correct code for the { "typeof": true } option with global declaration:

/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Environments

For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.

browser

Examples of correct code for this rule with browser environment:

/*eslint no-undef: "error"*/
/*eslint-env browser*/

setTimeout(function() {
    alert("Hello");
});

node

Examples of correct code for this rule with node environment:

/*eslint no-undef: "error"*/
/*eslint-env node*/

var fs = require("fs");
module.exports = function() {
    console.log(fs);
};

When Not To Use It

If explicit declaration of global variables is not to your taste.

Compatibility

This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/

'r' is defined but never used.
Open

      ).then((r)=>{
Severity: Minor
Found in tst/index.js by eslint

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 or commonjs
  • when parserOptions.sourceType is module
  • when ecmaFeatures.globalReturn is true

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/

Unexpected space before opening brace.
Open

  renderDir(inpDir, outDir) {
Severity: Minor
Found in index.js by eslint

Require Or Disallow Space Before Blocks (space-before-blocks)

Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.

Rule Details

This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.

  • This rule ignores spacing which is between => and a block. The spacing is handled by the arrow-spacing rule.
  • This rule ignores spacing which is between a keyword and a block. The spacing is handled by the keyword-spacing rule.

Options

This rule takes one argument. If it is "always" then blocks must always have at least one preceding space. If "never" then all blocks should never have any preceding space. If different spacing is desired for function blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to configure the cases separately.

( e.g. { "functions": "never", "keywords": "always", "classes": "always" } )

The default is "always".

"always"

Examples of incorrect code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try {} catch(a){}

class Foo{
  constructor(){}
}

Examples of correct code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a) {
    b();
}

if (a) {
    b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
    c();
}


function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

"never"

Examples of incorrect code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a) {
    b();
}

function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

Examples of correct code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try{} catch(a){}

class Foo{
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

function a() {}

try {} catch(a){}

class Foo{
  constructor() {}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

for (;;) {
  // ...
}

describe(function(){
  // ...
});

class Foo {
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

function a(){}

try {} catch(a) {}

class Foo {
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

if (a){
  b();
}

var a = function() {}

class Foo{
  constructor() {}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo{
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo {
  constructor(){}
}

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing before blocks.

Related Rules

Unexpected function expression.
Open

suite('ESF-PUML Suite',function(){
Severity: Minor
Found in tst/index.js by eslint

Suggest using arrow functions as callbacks. (prefer-arrow-callback)

Arrow functions are suited to callbacks, because:

  • this keywords in arrow functions bind to the upper scope's.
  • The notation of the arrow function is shorter than function expression's.

Rule Details

This rule is aimed to flag usage of function expressions in an argument list.

The following patterns are considered problems:

/*eslint prefer-arrow-callback: "error"*/

foo(function(a) { return a; });
foo(function() { return this.a; }.bind(this));

The following patterns are not considered problems:

/*eslint prefer-arrow-callback: "error"*/
/*eslint-env es6*/

foo(a => a);
foo(function*() { yield; });

// this is not a callback.
var foo = function foo(a) { return a; };

// using `this` without `.bind(this)`.
foo(function() { return this.a; });

// recursively.
foo(function bar(n) { return n && n + bar(n - 1); });

Options

This rule takes one optional argument, an object which is an options object.

allowNamedFunctions

This is a boolean option and it is false by default. When set to true, the rule doesn't warn on named functions used as callbacks.

Examples of correct code for the { "allowNamedFunctions": true } option:

/*eslint prefer-arrow-callback: ["error", { "allowNamedFunctions": true }]*/

foo(function bar() {});

allowUnboundThis

This is a boolean option and it is true by default. When set to false, this option allows the use of this without restriction and checks for dynamically assigned this values such as when using Array.prototype.map with a context argument. Normally, the rule will flag the use of this whenever a function does not use bind() to specify the value of this constantly.

Examples of incorrect code for the { "allowUnboundThis": false } option:

/*eslint prefer-arrow-callback: ["error", { "allowUnboundThis": false }]*/
/*eslint-env es6*/

foo(function() { this.a; });

foo(function() { (() => this); });

someArray.map(function (itm) { return this.doSomething(itm); }, someObject);

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 function expressions in an argument list, you can safely disable this rule. Source: http://eslint.org/docs/rules/

'test' is not defined.
Open

    test('relative include path with custom cwd set',done=>{
Severity: Minor
Found in tst/index.js by eslint

Disallow Undeclared Variables (no-undef)

This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var keyword in a for loop initializer).

Rule Details

Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/ comment.

Examples of incorrect code for this rule:

/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

Examples of correct code for this rule with global declaration:

/*global someFunction b:true*/
/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

The b:true syntax in /*global */ indicates that assignment to b is correct.

Examples of incorrect code for this rule with global declaration:

/*global b*/
/*eslint no-undef: "error"*/

b = 10;

By default, variables declared in /*global */ are read-only, therefore assignment is incorrect.

Options

  • typeof set to true will warn for variables used inside typeof check (Default false).

typeof

Examples of correct code for the default { "typeof": false } option:

/*eslint no-undef: "error"*/

if (typeof UndefinedIdentifier === "undefined") {
    // do something ...
}

You can use this option if you want to prevent typeof check on a variable which has not been declared.

Examples of incorrect code for the { "typeof": true } option:

/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Examples of correct code for the { "typeof": true } option with global declaration:

/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Environments

For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.

browser

Examples of correct code for this rule with browser environment:

/*eslint no-undef: "error"*/
/*eslint-env browser*/

setTimeout(function() {
    alert("Hello");
});

node

Examples of correct code for this rule with node environment:

/*eslint no-undef: "error"*/
/*eslint-env node*/

var fs = require("fs");
module.exports = function() {
    console.log(fs);
};

When Not To Use It

If explicit declaration of global variables is not to your taste.

Compatibility

This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/

Unexpected space between function name and paren.
Open

        var rs=fs.createReadStream ( inpFile,{encoding:'utf8', autoClose: true} );
Severity: Minor
Found in tst/index.js by eslint

disallow spacing between function identifiers and their applications (no-spaced-func)

This rule was deprecated in ESLint v3.3.0 and replaced by the [func-call-spacing](func-call-spacing.md) rule.

While it's possible to have whitespace between the name of a function and the parentheses that execute it, such patterns tend to look more like errors.

Rule Details

This rule disallows spacing between function identifiers and their applications.

Examples of incorrect code for this rule:

/*eslint no-spaced-func: "error"*/

fn ()

fn
()

Examples of correct code for this rule:

/*eslint no-spaced-func: "error"*/

fn()

Source: http://eslint.org/docs/rules/

Unexpected space before opening brace.
Open

          if (!r2) {
Severity: Minor
Found in index.js by eslint

Require Or Disallow Space Before Blocks (space-before-blocks)

Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.

Rule Details

This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.

  • This rule ignores spacing which is between => and a block. The spacing is handled by the arrow-spacing rule.
  • This rule ignores spacing which is between a keyword and a block. The spacing is handled by the keyword-spacing rule.

Options

This rule takes one argument. If it is "always" then blocks must always have at least one preceding space. If "never" then all blocks should never have any preceding space. If different spacing is desired for function blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to configure the cases separately.

( e.g. { "functions": "never", "keywords": "always", "classes": "always" } )

The default is "always".

"always"

Examples of incorrect code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try {} catch(a){}

class Foo{
  constructor(){}
}

Examples of correct code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a) {
    b();
}

if (a) {
    b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
    c();
}


function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

"never"

Examples of incorrect code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a) {
    b();
}

function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

Examples of correct code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try{} catch(a){}

class Foo{
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

function a() {}

try {} catch(a){}

class Foo{
  constructor() {}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

for (;;) {
  // ...
}

describe(function(){
  // ...
});

class Foo {
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

function a(){}

try {} catch(a) {}

class Foo {
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

if (a){
  b();
}

var a = function() {}

class Foo{
  constructor() {}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo{
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo {
  constructor(){}
}

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing before blocks.

Related Rules

Unexpected space before opening brace.
Open

  renderString(strIn, fileOut) {
Severity: Minor
Found in index.js by eslint

Require Or Disallow Space Before Blocks (space-before-blocks)

Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.

Rule Details

This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.

  • This rule ignores spacing which is between => and a block. The spacing is handled by the arrow-spacing rule.
  • This rule ignores spacing which is between a keyword and a block. The spacing is handled by the keyword-spacing rule.

Options

This rule takes one argument. If it is "always" then blocks must always have at least one preceding space. If "never" then all blocks should never have any preceding space. If different spacing is desired for function blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to configure the cases separately.

( e.g. { "functions": "never", "keywords": "always", "classes": "always" } )

The default is "always".

"always"

Examples of incorrect code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try {} catch(a){}

class Foo{
  constructor(){}
}

Examples of correct code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a) {
    b();
}

if (a) {
    b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
    c();
}


function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

"never"

Examples of incorrect code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a) {
    b();
}

function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

Examples of correct code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try{} catch(a){}

class Foo{
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

function a() {}

try {} catch(a){}

class Foo{
  constructor() {}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

for (;;) {
  // ...
}

describe(function(){
  // ...
});

class Foo {
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

function a(){}

try {} catch(a) {}

class Foo {
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

if (a){
  b();
}

var a = function() {}

class Foo{
  constructor() {}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo{
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo {
  constructor(){}
}

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing before blocks.

Related Rules

Unexpected space before opening brace.
Open

      write: function write(d, encoding, next) {
Severity: Minor
Found in index.js by eslint

Require Or Disallow Space Before Blocks (space-before-blocks)

Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.

Rule Details

This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.

  • This rule ignores spacing which is between => and a block. The spacing is handled by the arrow-spacing rule.
  • This rule ignores spacing which is between a keyword and a block. The spacing is handled by the keyword-spacing rule.

Options

This rule takes one argument. If it is "always" then blocks must always have at least one preceding space. If "never" then all blocks should never have any preceding space. If different spacing is desired for function blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to configure the cases separately.

( e.g. { "functions": "never", "keywords": "always", "classes": "always" } )

The default is "always".

"always"

Examples of incorrect code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try {} catch(a){}

class Foo{
  constructor(){}
}

Examples of correct code for this rule with the "always" option:

/*eslint space-before-blocks: "error"*/

if (a) {
    b();
}

if (a) {
    b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
    c();
}


function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

"never"

Examples of incorrect code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a) {
    b();
}

function a() {}

for (;;) {
    b();
}

try {} catch(a) {}

Examples of correct code for this rule with the "never" option:

/*eslint space-before-blocks: ["error", "never"]*/

if (a){
    b();
}

function a(){}

for (;;){
    b();
}

try{} catch(a){}

class Foo{
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

function a() {}

try {} catch(a){}

class Foo{
  constructor() {}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/

for (;;) {
  // ...
}

describe(function(){
  // ...
});

class Foo {
  constructor(){}
}

Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

function a(){}

try {} catch(a) {}

class Foo {
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }:

/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/

if (a){
  b();
}

var a = function() {}

class Foo{
  constructor() {}
}

Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo{
  constructor(){}
}

Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }:

/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/

class Foo {
  constructor(){}
}

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing before blocks.

Related Rules

Properties shouldn't be quoted as all quotes are redundant.
Open

  "rt" :path.resolve(__dirname+'/d')
Severity: Minor
Found in tst/index.js by eslint

require quotes around object literal property names (quote-props)

Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:

var object1 = {
    property: true
};

var object2 = {
    "property": true
};

In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.

There are, however, some occasions when you must use quotes:

  1. If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as if) as a property name. This restriction was removed in ECMAScript 5.
  2. You want to use a non-identifier character in your property name, such as having a property with a space like "one two".

Another example where quotes do matter is when using numeric literals as property keys:

var object = {
    1e2: 1,
    100: 2
};

This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2 and 100 are coerced into strings before getting used as the property name. Both String(1e2) and String(100) happen to be equal to "100", which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.

Rule Details

This rule requires quotes around object literal property names.

Options

This rule has two options, a string option and an object option.

String option:

  • "always" (default) requires quotes around all object literal property names
  • "as-needed" disallows quotes around object literal property names that are not strictly required
  • "consistent" enforces a consistent quote style requires quotes around object literal property names
  • "consistent-as-needed" requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names

Object option:

  • "keywords": true requires quotes around language keywords used as object property names (only applies when using as-needed or consistent-as-needed)
  • "unnecessary": true (default) disallows quotes around object literal property names that are not strictly required (only applies when using as-needed)
  • "unnecessary": false allows quotes around object literal property names that are not strictly required (only applies when using as-needed)
  • "numbers": true requires quotes around numbers used as object property names (only applies when using as-needed)

always

Examples of incorrect code for this rule with the default "always" option:

/*eslint quote-props: ["error", "always"]*/

var object = {
    foo: "bar",
    baz: 42,
    "qux-lorem": true
};

Examples of correct code for this rule with the default "always" option:

/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/

var object1 = {
    "foo": "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    'baz': 42,
    'qux-lorem': true
};

var object3 = {
    foo() {
        return;
    }
};

as-needed

Examples of incorrect code for this rule with the "as-needed" option:

/*eslint quote-props: ["error", "as-needed"]*/

var object = {
    "a": 0,
    "0": 0,
    "true": 0,
    "null": 0
};

Examples of correct code for this rule with the "as-needed" option:

/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/

var object1 = {
    "a-b": 0,
    "0x0": 0,
    "1e2": 0
};

var object2 = {
    foo: 'bar',
    baz: 42,
    true: 0,
    0: 0,
    'qux-lorem': true
};

var object3 = {
    foo() {
        return;
    }
};

consistent

Examples of incorrect code for this rule with the "consistent" option:

/*eslint quote-props: ["error", "consistent"]*/

var object1 = {
    foo: "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    baz: 42
};

Examples of correct code for this rule with the "consistent" option:

/*eslint quote-props: ["error", "consistent"]*/

var object1 = {
    "foo": "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    'baz': 42
};

var object3 = {
    foo: 'bar',
    baz: 42
};

consistent-as-needed

Examples of incorrect code for this rule with the "consistent-as-needed" option:

/*eslint quote-props: ["error", "consistent-as-needed"]*/

var object1 = {
    foo: "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    'baz': 42
};

Examples of correct code for this rule with the "consistent-as-needed" option:

/*eslint quote-props: ["error", "consistent-as-needed"]*/

var object1 = {
    "foo": "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    foo: 'bar',
    baz: 42
};

keywords

Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true } options:

/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/

var x = {
    while: 1,
    volatile: "foo"
};

Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true } options:

/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/

var x = {
    "prop": 1,
    "bar": "foo"
};

unnecessary

Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false } options:

/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/

var x = {
    "while": 1,
    "foo": "bar"  // Would normally have caused a warning
};

numbers

Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true } options:

/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/

var x = {
    100: 1
}

When Not To Use It

If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.

Further Reading

Unexpected console statement.
Open

          console.log('');
Severity: Minor
Found in tst/index.js by eslint

disallow the use of console (no-console)

In JavaScript that is designed to be executed in the browser, it's considered a best practice to avoid using methods on console. Such messages are considered to be for debugging purposes and therefore not suitable to ship to the client. In general, calls using console should be stripped before being pushed to production.

console.log("Made it here.");
console.error("That shouldn't have happened.");

Rule Details

This rule disallows calls to methods of the console object.

Examples of incorrect code for this rule:

/*eslint no-console: "error"*/

console.log("Log a debug level message.");
console.warn("Log a warn level message.");
console.error("Log an error level message.");

Examples of correct code for this rule:

/*eslint no-console: "error"*/

// custom console
Console.log("Hello world!");

Options

This rule has an object option for exceptions:

  • "allow" has an array of strings which are allowed methods of the console object

Examples of additional correct code for this rule with a sample { "allow": ["warn", "error"] } option:

/*eslint no-console: ["error", { allow: ["warn", "error"] }] */

console.warn("Log a warn level message.");
console.error("Log an error level message.");

When Not To Use It

If you're using Node.js, however, console is used to output information to the user and so is not strictly used for debugging purposes. If you are developing for Node.js then you most likely do not want this rule enabled.

Related Rules

Properties shouldn't be quoted as all quotes are redundant.
Open

  "inp":path.resolve(__dirname+'/d/inp'),
Severity: Minor
Found in tst/index.js by eslint

require quotes around object literal property names (quote-props)

Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:

var object1 = {
    property: true
};

var object2 = {
    "property": true
};

In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.

There are, however, some occasions when you must use quotes:

  1. If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as if) as a property name. This restriction was removed in ECMAScript 5.
  2. You want to use a non-identifier character in your property name, such as having a property with a space like "one two".

Another example where quotes do matter is when using numeric literals as property keys:

var object = {
    1e2: 1,
    100: 2
};

This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2 and 100 are coerced into strings before getting used as the property name. Both String(1e2) and String(100) happen to be equal to "100", which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.

Rule Details

This rule requires quotes around object literal property names.

Options

This rule has two options, a string option and an object option.

String option:

  • "always" (default) requires quotes around all object literal property names
  • "as-needed" disallows quotes around object literal property names that are not strictly required
  • "consistent" enforces a consistent quote style requires quotes around object literal property names
  • "consistent-as-needed" requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names

Object option:

  • "keywords": true requires quotes around language keywords used as object property names (only applies when using as-needed or consistent-as-needed)
  • "unnecessary": true (default) disallows quotes around object literal property names that are not strictly required (only applies when using as-needed)
  • "unnecessary": false allows quotes around object literal property names that are not strictly required (only applies when using as-needed)
  • "numbers": true requires quotes around numbers used as object property names (only applies when using as-needed)

always

Examples of incorrect code for this rule with the default "always" option:

/*eslint quote-props: ["error", "always"]*/

var object = {
    foo: "bar",
    baz: 42,
    "qux-lorem": true
};

Examples of correct code for this rule with the default "always" option:

/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/

var object1 = {
    "foo": "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    'baz': 42,
    'qux-lorem': true
};

var object3 = {
    foo() {
        return;
    }
};

as-needed

Examples of incorrect code for this rule with the "as-needed" option:

/*eslint quote-props: ["error", "as-needed"]*/

var object = {
    "a": 0,
    "0": 0,
    "true": 0,
    "null": 0
};

Examples of correct code for this rule with the "as-needed" option:

/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/

var object1 = {
    "a-b": 0,
    "0x0": 0,
    "1e2": 0
};

var object2 = {
    foo: 'bar',
    baz: 42,
    true: 0,
    0: 0,
    'qux-lorem': true
};

var object3 = {
    foo() {
        return;
    }
};

consistent

Examples of incorrect code for this rule with the "consistent" option:

/*eslint quote-props: ["error", "consistent"]*/

var object1 = {
    foo: "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    baz: 42
};

Examples of correct code for this rule with the "consistent" option:

/*eslint quote-props: ["error", "consistent"]*/

var object1 = {
    "foo": "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    'baz': 42
};

var object3 = {
    foo: 'bar',
    baz: 42
};

consistent-as-needed

Examples of incorrect code for this rule with the "consistent-as-needed" option:

/*eslint quote-props: ["error", "consistent-as-needed"]*/

var object1 = {
    foo: "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    'foo': 'bar',
    'baz': 42
};

Examples of correct code for this rule with the "consistent-as-needed" option:

/*eslint quote-props: ["error", "consistent-as-needed"]*/

var object1 = {
    "foo": "bar",
    "baz": 42,
    "qux-lorem": true
};

var object2 = {
    foo: 'bar',
    baz: 42
};

keywords

Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true } options:

/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/

var x = {
    while: 1,
    volatile: "foo"
};

Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true } options:

/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/

var x = {
    "prop": 1,
    "bar": "foo"
};

unnecessary

Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false } options:

/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/

var x = {
    "while": 1,
    "foo": "bar"  // Would normally have caused a warning
};

numbers

Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true } options:

/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/

var x = {
    100: 1
}

When Not To Use It

If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.

Further Reading

'test' is not defined.
Open

    test('renderDir',done=>{
Severity: Minor
Found in tst/index.js by eslint

Disallow Undeclared Variables (no-undef)

This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var keyword in a for loop initializer).

Rule Details

Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/ comment.

Examples of incorrect code for this rule:

/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

Examples of correct code for this rule with global declaration:

/*global someFunction b:true*/
/*eslint no-undef: "error"*/

var a = someFunction();
b = 10;

The b:true syntax in /*global */ indicates that assignment to b is correct.

Examples of incorrect code for this rule with global declaration:

/*global b*/
/*eslint no-undef: "error"*/

b = 10;

By default, variables declared in /*global */ are read-only, therefore assignment is incorrect.

Options

  • typeof set to true will warn for variables used inside typeof check (Default false).

typeof

Examples of correct code for the default { "typeof": false } option:

/*eslint no-undef: "error"*/

if (typeof UndefinedIdentifier === "undefined") {
    // do something ...
}

You can use this option if you want to prevent typeof check on a variable which has not been declared.

Examples of incorrect code for the { "typeof": true } option:

/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Examples of correct code for the { "typeof": true } option with global declaration:

/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */

if(typeof a === "string"){}

Environments

For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.

browser

Examples of correct code for this rule with browser environment:

/*eslint no-undef: "error"*/
/*eslint-env browser*/

setTimeout(function() {
    alert("Hello");
});

node

Examples of correct code for this rule with node environment:

/*eslint no-undef: "error"*/
/*eslint-env node*/

var fs = require("fs");
module.exports = function() {
    console.log(fs);
};

When Not To Use It

If explicit declaration of global variables is not to your taste.

Compatibility

This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/

Unexpected space between function name and paren.
Open

          var rs=fs.createReadStream ( path.resolve(dir.inp+'/'+inpFile+'.puml'),{encoding:'utf8', autoClose: true} );
Severity: Minor
Found in tst/index.js by eslint

disallow spacing between function identifiers and their applications (no-spaced-func)

This rule was deprecated in ESLint v3.3.0 and replaced by the [func-call-spacing](func-call-spacing.md) rule.

While it's possible to have whitespace between the name of a function and the parentheses that execute it, such patterns tend to look more like errors.

Rule Details

This rule disallows spacing between function identifiers and their applications.

Examples of incorrect code for this rule:

/*eslint no-spaced-func: "error"*/

fn ()

fn
()

Examples of correct code for this rule:

/*eslint no-spaced-func: "error"*/

fn()

Source: http://eslint.org/docs/rules/

Severity
Category
Status
Source
Language