Rule: semicolon

Enforces consistent semicolon usage at the end of every statement.

Notes

• Has Fix

Config

One of the following arguments must be provided:

• "always" enforces semicolons at the end of every statement.
• "never" disallows semicolons at the end of every statement except for when they are necessary.

The following arguments may be optionally provided:

• "ignore-interfaces" skips checking semicolons at the end of interface members.
• "ignore-bound-class-methods" skips checking semicolons at the end of bound class methods.
• "strict-bound-class-methods" disables any special handling of bound class methods and treats them as any other assignment. This option overrides "ignore-bound-class-methods".

Examples

"semicolon": true,always

"semicolon": true,never

"semicolon": true,always,ignore-interfaces

"semicolon": true,always,ignore-bound-class-methods

Schema

{
  "type": "array",
  "items": [
    {
      "type": "string",
      "enum": [
        "always",
        "never"
      ]
    },
    {
      "type": "string",
      "enum": [
        "ignore-interfaces"
      ]
    }
  ],
  "additionalItems": false
}

For more information see this page.

Rule: whitespace

Enforces whitespace style conventions.

Rationale

Helps maintain a readable, consistent style in your codebase.

Notes

• Has Fix

Config

Several arguments may be optionally provided:

• "check-branch" checks branching statements (if/else/for/while) are followed by whitespace.
• "check-decl"checks that variable declarations have whitespace around the equals token.
• "check-operator" checks for whitespace around operator tokens.
• "check-module" checks for whitespace in import & export statements.
• "check-separator" checks for whitespace after separator tokens (,/;).
• "check-rest-spread" checks that there is no whitespace after rest/spread operator (...).
• "check-type" checks for whitespace before a variable type specification.
• "check-typecast" checks for whitespace between a typecast and its target.
• "check-type-operator" checks for whitespace between type operators | and &.
• "check-preblock" checks for whitespace before the opening brace of a block.
• "check-postbrace" checks for whitespace after an opening brace.

Examples

"whitespace": true,check-branch,check-operator,check-typecast

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "check-branch",
      "check-decl",
      "check-operator",
      "check-module",
      "check-separator",
      "check-rest-spread",
      "check-type",
      "check-typecast",
      "check-type-operator",
      "check-preblock",
      "check-postbrace"
    ]
  },
  "minLength": 0,
  "maxLength": 11
}

For more information see this page.

Rule: curly

Enforces braces for if/for/do/while statements.

Rationale

if (foo === bar)
    foo++;
    bar++;

In the code above, the author almost certainly meant for both foo++ and bar++ to be executed only if foo === bar. However, they forgot braces and bar++ will be executed no matter what. This rule could prevent such a mistake.

Notes

• Has Fix

Config

One of the following options may be provided:

• "as-needed" forbids any unnecessary curly braces.
• "ignore-same-line" skips checking braces for control-flow statements that are on one line and start on the same line as their control-flow keyword

Examples

"curly": true

"curly": true,ignore-same-line

"curly": true,as-needed

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "as-needed",
      "ignore-same-line"
    ]
  }
}

For more information see this page.

Rule: curly

Enforces braces for if/for/do/while statements.

Rationale

if (foo === bar)
    foo++;
    bar++;

In the code above, the author almost certainly meant for both foo++ and bar++ to be executed only if foo === bar. However, they forgot braces and bar++ will be executed no matter what. This rule could prevent such a mistake.

Notes

• Has Fix

Config

One of the following options may be provided:

• "as-needed" forbids any unnecessary curly braces.
• "ignore-same-line" skips checking braces for control-flow statements that are on one line and start on the same line as their control-flow keyword

Examples

"curly": true

"curly": true,ignore-same-line

"curly": true,as-needed

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "as-needed",
      "ignore-same-line"
    ]
  }
}

For more information see this page.

Rule: prefer-const

Requires that variable declarations use const instead of let and var if possible.

If a variable is only assigned to once when it is declared, it should be declared using 'const'

Notes

• Has Fix

Config

An optional object containing the property "destructuring" with two possible values:

• "any" (default) - If any variable in destructuring can be const, this rule warns for those variables.
• "all" - Only warns if all variables in destructuring can be const.

Examples

"prefer-const": true

"prefer-const": true,[object Object]

Schema

{
  "type": "object",
  "properties": {
    "destructuring": {
      "type": "string",
      "enum": [
        "all",
        "any"
      ]
    }
  }
}

For more information see this page.