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 62.

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

Rule: comment-format

Enforces formatting rules for single-line comments.

Rationale

Helps maintain a consistent, readable style in your codebase.

Notes

• Has Fix

Config

Four arguments may be optionally provided:

• "check-space" requires that all single-line comments must begin with a space, as in // comment
  • note that for comments starting with multiple slashes, e.g. ///, leading slashes are ignored
  • TypeScript reference comments are ignored completely
• "check-lowercase" requires that the first non-whitespace character of a comment must be lowercase, if applicable.
• "check-uppercase" requires that the first non-whitespace character of a comment must be uppercase, if applicable.
• "allow-trailing-lowercase" allows that only the first comment of a series of comments needs to be uppercase.
  • requires "check-uppercase"
  • comments must start at the same position

Exceptions to "check-lowercase" or "check-uppercase" can be managed with object that may be passed as last argument.

One of two options can be provided in this object:

• "ignore-words" - array of strings - words that will be ignored at the beginning of the comment.
• "ignore-pattern" - string - RegExp pattern that will be ignored at the beginning of the comment.

Examples

"comment-format": true,check-space,check-uppercase,allow-trailing-lowercase

"comment-format": true,check-lowercase,[object Object]

"comment-format": true,check-lowercase,[object Object]

Schema

{
  "type": "array",
  "items": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "check-space",
          "check-lowercase",
          "check-uppercase",
          "allow-trailing-lowercase"
        ]
      },
      {
        "type": "object",
        "properties": {
          "ignore-words": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "ignore-pattern": {
            "type": "string"
          }
        },
        "minProperties": 1,
        "maxProperties": 1
      }
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: align

Enforces vertical alignment.

Rationale

Helps maintain a readable, consistent style in your codebase.

Consistent alignment for code statements helps keep code readable and clear. Statements misaligned from the standard can be harder to read and understand.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "parameters" checks alignment of function parameters.
• "arguments" checks alignment of function call arguments.
• "statements" checks alignment of statements.
• "members" checks alignment of members of classes, interfaces, type literal, object literals and object destructuring.
• "elements" checks alignment of elements of array literals, array destructuring and tuple types.

Examples

"align": true,parameters,statements

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "arguments",
      "elements",
      "members",
      "parameters",
      "statements"
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: comment-format

Enforces formatting rules for single-line comments.

Rationale

Helps maintain a consistent, readable style in your codebase.

Notes

• Has Fix

Config

Four arguments may be optionally provided:

• "check-space" requires that all single-line comments must begin with a space, as in // comment
  • note that for comments starting with multiple slashes, e.g. ///, leading slashes are ignored
  • TypeScript reference comments are ignored completely
• "check-lowercase" requires that the first non-whitespace character of a comment must be lowercase, if applicable.
• "check-uppercase" requires that the first non-whitespace character of a comment must be uppercase, if applicable.
• "allow-trailing-lowercase" allows that only the first comment of a series of comments needs to be uppercase.
  • requires "check-uppercase"
  • comments must start at the same position

Exceptions to "check-lowercase" or "check-uppercase" can be managed with object that may be passed as last argument.

One of two options can be provided in this object:

• "ignore-words" - array of strings - words that will be ignored at the beginning of the comment.
• "ignore-pattern" - string - RegExp pattern that will be ignored at the beginning of the comment.

Examples

"comment-format": true,check-space,check-uppercase,allow-trailing-lowercase

"comment-format": true,check-lowercase,[object Object]

"comment-format": true,check-lowercase,[object Object]

Schema

{
  "type": "array",
  "items": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "check-space",
          "check-lowercase",
          "check-uppercase",
          "allow-trailing-lowercase"
        ]
      },
      {
        "type": "object",
        "properties": {
          "ignore-words": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "ignore-pattern": {
            "type": "string"
          }
        },
        "minProperties": 1,
        "maxProperties": 1
      }
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: align

Enforces vertical alignment.

Rationale

Helps maintain a readable, consistent style in your codebase.

Consistent alignment for code statements helps keep code readable and clear. Statements misaligned from the standard can be harder to read and understand.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "parameters" checks alignment of function parameters.
• "arguments" checks alignment of function call arguments.
• "statements" checks alignment of statements.
• "members" checks alignment of members of classes, interfaces, type literal, object literals and object destructuring.
• "elements" checks alignment of elements of array literals, array destructuring and tuple types.

Examples

"align": true,parameters,statements

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "arguments",
      "elements",
      "members",
      "parameters",
      "statements"
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

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: align

Enforces vertical alignment.

Rationale

Helps maintain a readable, consistent style in your codebase.

Consistent alignment for code statements helps keep code readable and clear. Statements misaligned from the standard can be harder to read and understand.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "parameters" checks alignment of function parameters.
• "arguments" checks alignment of function call arguments.
• "statements" checks alignment of statements.
• "members" checks alignment of members of classes, interfaces, type literal, object literals and object destructuring.
• "elements" checks alignment of elements of array literals, array destructuring and tuple types.

Examples

"align": true,parameters,statements

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "arguments",
      "elements",
      "members",
      "parameters",
      "statements"
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: comment-format

Enforces formatting rules for single-line comments.

Rationale

Helps maintain a consistent, readable style in your codebase.

Notes

• Has Fix

Config

Four arguments may be optionally provided:

• "check-space" requires that all single-line comments must begin with a space, as in // comment
  • note that for comments starting with multiple slashes, e.g. ///, leading slashes are ignored
  • TypeScript reference comments are ignored completely
• "check-lowercase" requires that the first non-whitespace character of a comment must be lowercase, if applicable.
• "check-uppercase" requires that the first non-whitespace character of a comment must be uppercase, if applicable.
• "allow-trailing-lowercase" allows that only the first comment of a series of comments needs to be uppercase.
  • requires "check-uppercase"
  • comments must start at the same position

Exceptions to "check-lowercase" or "check-uppercase" can be managed with object that may be passed as last argument.

One of two options can be provided in this object:

• "ignore-words" - array of strings - words that will be ignored at the beginning of the comment.
• "ignore-pattern" - string - RegExp pattern that will be ignored at the beginning of the comment.

Examples

"comment-format": true,check-space,check-uppercase,allow-trailing-lowercase

"comment-format": true,check-lowercase,[object Object]

"comment-format": true,check-lowercase,[object Object]

Schema

{
  "type": "array",
  "items": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "check-space",
          "check-lowercase",
          "check-uppercase",
          "allow-trailing-lowercase"
        ]
      },
      {
        "type": "object",
        "properties": {
          "ignore-words": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "ignore-pattern": {
            "type": "string"
          }
        },
        "minProperties": 1,
        "maxProperties": 1
      }
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: comment-format

Enforces formatting rules for single-line comments.

Rationale

Helps maintain a consistent, readable style in your codebase.

Notes

• Has Fix

Config

Four arguments may be optionally provided:

• "check-space" requires that all single-line comments must begin with a space, as in // comment
  • note that for comments starting with multiple slashes, e.g. ///, leading slashes are ignored
  • TypeScript reference comments are ignored completely
• "check-lowercase" requires that the first non-whitespace character of a comment must be lowercase, if applicable.
• "check-uppercase" requires that the first non-whitespace character of a comment must be uppercase, if applicable.
• "allow-trailing-lowercase" allows that only the first comment of a series of comments needs to be uppercase.
  • requires "check-uppercase"
  • comments must start at the same position

Exceptions to "check-lowercase" or "check-uppercase" can be managed with object that may be passed as last argument.

One of two options can be provided in this object:

• "ignore-words" - array of strings - words that will be ignored at the beginning of the comment.
• "ignore-pattern" - string - RegExp pattern that will be ignored at the beginning of the comment.

Examples

"comment-format": true,check-space,check-uppercase,allow-trailing-lowercase

"comment-format": true,check-lowercase,[object Object]

"comment-format": true,check-lowercase,[object Object]

Schema

{
  "type": "array",
  "items": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "check-space",
          "check-lowercase",
          "check-uppercase",
          "allow-trailing-lowercase"
        ]
      },
      {
        "type": "object",
        "properties": {
          "ignore-words": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "ignore-pattern": {
            "type": "string"
          }
        },
        "minProperties": 1,
        "maxProperties": 1
      }
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: comment-format

Enforces formatting rules for single-line comments.

Rationale

Helps maintain a consistent, readable style in your codebase.

Notes

• Has Fix

Config

Four arguments may be optionally provided:

• "check-space" requires that all single-line comments must begin with a space, as in // comment
  • note that for comments starting with multiple slashes, e.g. ///, leading slashes are ignored
  • TypeScript reference comments are ignored completely
• "check-lowercase" requires that the first non-whitespace character of a comment must be lowercase, if applicable.
• "check-uppercase" requires that the first non-whitespace character of a comment must be uppercase, if applicable.
• "allow-trailing-lowercase" allows that only the first comment of a series of comments needs to be uppercase.
  • requires "check-uppercase"
  • comments must start at the same position

Exceptions to "check-lowercase" or "check-uppercase" can be managed with object that may be passed as last argument.

One of two options can be provided in this object:

• "ignore-words" - array of strings - words that will be ignored at the beginning of the comment.
• "ignore-pattern" - string - RegExp pattern that will be ignored at the beginning of the comment.

Examples

"comment-format": true,check-space,check-uppercase,allow-trailing-lowercase

"comment-format": true,check-lowercase,[object Object]

"comment-format": true,check-lowercase,[object Object]

Schema

{
  "type": "array",
  "items": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "check-space",
          "check-lowercase",
          "check-uppercase",
          "allow-trailing-lowercase"
        ]
      },
      {
        "type": "object",
        "properties": {
          "ignore-words": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "ignore-pattern": {
            "type": "string"
          }
        },
        "minProperties": 1,
        "maxProperties": 1
      }
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

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: 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: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: align

Enforces vertical alignment.

Rationale

Helps maintain a readable, consistent style in your codebase.

Consistent alignment for code statements helps keep code readable and clear. Statements misaligned from the standard can be harder to read and understand.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "parameters" checks alignment of function parameters.
• "arguments" checks alignment of function call arguments.
• "statements" checks alignment of statements.
• "members" checks alignment of members of classes, interfaces, type literal, object literals and object destructuring.
• "elements" checks alignment of elements of array literals, array destructuring and tuple types.

Examples

"align": true,parameters,statements

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "arguments",
      "elements",
      "members",
      "parameters",
      "statements"
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: align

Enforces vertical alignment.

Rationale

Helps maintain a readable, consistent style in your codebase.

Consistent alignment for code statements helps keep code readable and clear. Statements misaligned from the standard can be harder to read and understand.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "parameters" checks alignment of function parameters.
• "arguments" checks alignment of function call arguments.
• "statements" checks alignment of statements.
• "members" checks alignment of members of classes, interfaces, type literal, object literals and object destructuring.
• "elements" checks alignment of elements of array literals, array destructuring and tuple types.

Examples

"align": true,parameters,statements

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "arguments",
      "elements",
      "members",
      "parameters",
      "statements"
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

Rule: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.

Rule: comment-format

Enforces formatting rules for single-line comments.

Rationale

Helps maintain a consistent, readable style in your codebase.

Notes

• Has Fix

Config

Four arguments may be optionally provided:

• "check-space" requires that all single-line comments must begin with a space, as in // comment
  • note that for comments starting with multiple slashes, e.g. ///, leading slashes are ignored
  • TypeScript reference comments are ignored completely
• "check-lowercase" requires that the first non-whitespace character of a comment must be lowercase, if applicable.
• "check-uppercase" requires that the first non-whitespace character of a comment must be uppercase, if applicable.
• "allow-trailing-lowercase" allows that only the first comment of a series of comments needs to be uppercase.
  • requires "check-uppercase"
  • comments must start at the same position

Exceptions to "check-lowercase" or "check-uppercase" can be managed with object that may be passed as last argument.

One of two options can be provided in this object:

• "ignore-words" - array of strings - words that will be ignored at the beginning of the comment.
• "ignore-pattern" - string - RegExp pattern that will be ignored at the beginning of the comment.

Examples

"comment-format": true,check-space,check-uppercase,allow-trailing-lowercase

"comment-format": true,check-lowercase,[object Object]

"comment-format": true,check-lowercase,[object Object]

Schema

{
  "type": "array",
  "items": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "check-space",
          "check-lowercase",
          "check-uppercase",
          "allow-trailing-lowercase"
        ]
      },
      {
        "type": "object",
        "properties": {
          "ignore-words": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "ignore-pattern": {
            "type": "string"
          }
        },
        "minProperties": 1,
        "maxProperties": 1
      }
    ]
  },
  "minLength": 1,
  "maxLength": 5
}

For more information see this page.

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: 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: quotemark

Enforces quote character for string literals.

Notes

• Has Fix

Config

Five arguments may be optionally provided:

• "single" enforces single quotes.
• "double" enforces double quotes.
• "backtick" enforces backticks.
• "jsx-single" enforces single quotes for JSX attributes.
• "jsx-double" enforces double quotes for JSX attributes.
• "avoid-template" forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if "avoid-escape" is enabled and both single and double quotes are present in the string (the latter option takes precedence).
• "avoid-escape" allows you to use the "other" quotemark in cases where escaping would normally be required. For example, [true, "double", "avoid-escape"] would not report a failure on the string literal 'Hello "World"'.

Examples

"quotemark": true,single,avoid-escape,avoid-template

"quotemark": true,single,jsx-double

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "single",
      "double",
      "backtick",
      "jsx-single",
      "jsx-double",
      "avoid-escape",
      "avoid-template"
    ]
  },
  "minLength": 0,
  "maxLength": 5
}

For more information see this page.