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 50.

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

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 50.

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: 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: no-inferrable-types

Disallows explicit type declarations for variables or parameters initialized to a number, string, or boolean.

Rationale

Explicit types where they can be easily inferred by the compiler make code more verbose.

Notes

• TypeScript Only
• Has Fix

Config

Two arguments may be optionally provided:

• ignore-params allows specifying an inferrable type annotation for function params. This can be useful when combining with the typedef rule.
• ignore-properties allows specifying an inferrable type annotation for class properties.

Examples

"no-inferrable-types": true

"no-inferrable-types": true,ignore-params

"no-inferrable-types": true,ignore-params,ignore-properties

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "ignore-params",
      "ignore-properties"
    ]
  },
  "minLength": 0,
  "maxLength": 2
}

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: directive-class-suffix

Classes decorated with @Directive must have suffix "Directive" (or custom) in their name.

See more at https://angular.io/styleguide#style-02-03.

Rationale

Consistent conventions make it easy to quickly identify and reference assets of different types.

Notes

• TypeScript Only

Config

Supply a list of allowed component suffixes. Defaults to "Directive".

Examples

"directive-class-suffix": true

"directive-class-suffix": true,Directive,MySuffix

Schema

{
  "items": {
    "type": "string"
  },
  "minLength": 0,
  "type": "array"
}

For more information see this page.

Rule: no-trailing-whitespace

Disallows trailing whitespace at the end of a line.

Rationale

Keeps version control diffs clean as it prevents accidental whitespace from being committed.

Notes

• Has Fix

Config

Possible settings are:

• "ignore-template-strings": Allows trailing whitespace in template strings.
• "ignore-comments": Allows trailing whitespace in comments.
• "ignore-jsdoc": Allows trailing whitespace only in JSDoc comments.
• "ignore-blank-lines": Allows trailing whitespace on empty lines.

Examples

"no-trailing-whitespace": true

"no-trailing-whitespace": true,ignore-comments

"no-trailing-whitespace": true,ignore-jsdoc

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "ignore-comments",
      "ignore-jsdoc",
      "ignore-template-strings",
      "ignore-blank-lines"
    ]
  }
}

For more information see this page.

Rule: directive-class-suffix

Classes decorated with @Directive must have suffix "Directive" (or custom) in their name.

See more at https://angular.io/styleguide#style-02-03.

Rationale

Consistent conventions make it easy to quickly identify and reference assets of different types.

Notes

• TypeScript Only

Config

Supply a list of allowed component suffixes. Defaults to "Directive".

Examples

"directive-class-suffix": true

"directive-class-suffix": true,Directive,MySuffix

Schema

{
  "items": {
    "type": "string"
  },
  "minLength": 0,
  "type": "array"
}

For more information see this page.

Rule: directive-class-suffix

Classes decorated with @Directive must have suffix "Directive" (or custom) in their name.

See more at https://angular.io/styleguide#style-02-03.

Rationale

Consistent conventions make it easy to quickly identify and reference assets of different types.

Notes

• TypeScript Only

Config

Supply a list of allowed component suffixes. Defaults to "Directive".

Examples

"directive-class-suffix": true

"directive-class-suffix": true,Directive,MySuffix

Schema

{
  "items": {
    "type": "string"
  },
  "minLength": 0,
  "type": "array"
}

For more information see this page.

Rule: no-trailing-whitespace

Disallows trailing whitespace at the end of a line.

Rationale

Keeps version control diffs clean as it prevents accidental whitespace from being committed.

Notes

• Has Fix

Config

Possible settings are:

• "ignore-template-strings": Allows trailing whitespace in template strings.
• "ignore-comments": Allows trailing whitespace in comments.
• "ignore-jsdoc": Allows trailing whitespace only in JSDoc comments.
• "ignore-blank-lines": Allows trailing whitespace on empty lines.

Examples

"no-trailing-whitespace": true

"no-trailing-whitespace": true,ignore-comments

"no-trailing-whitespace": true,ignore-jsdoc

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "ignore-comments",
      "ignore-jsdoc",
      "ignore-template-strings",
      "ignore-blank-lines"
    ]
  }
}

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: no-trailing-whitespace

Disallows trailing whitespace at the end of a line.

Rationale

Keeps version control diffs clean as it prevents accidental whitespace from being committed.

Notes

• Has Fix

Config

Possible settings are:

• "ignore-template-strings": Allows trailing whitespace in template strings.
• "ignore-comments": Allows trailing whitespace in comments.
• "ignore-jsdoc": Allows trailing whitespace only in JSDoc comments.
• "ignore-blank-lines": Allows trailing whitespace on empty lines.

Examples

"no-trailing-whitespace": true

"no-trailing-whitespace": true,ignore-comments

"no-trailing-whitespace": true,ignore-jsdoc

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "ignore-comments",
      "ignore-jsdoc",
      "ignore-template-strings",
      "ignore-blank-lines"
    ]
  }
}

For more information see this page.

Rule: eofline

Ensures the file ends with a newline.

Fix for single-line files is not supported.

Rationale

It is a standard convention to end files with a newline.

Notes

• Has Fix

Config

Not configurable.

Examples

"eofline": true

For more information see this page.

Rule: typedef

Requires type definitions to exist.

Notes

• TypeScript Only

Config

Several arguments may be optionally provided:

• "call-signature" checks return type of functions.
• "arrow-call-signature" checks return type of arrow functions.
• "parameter" checks type specifier of function parameters for non-arrow functions.
• "arrow-parameter" checks type specifier of function parameters for arrow functions.
• "property-declaration" checks return types of interface properties.
• "variable-declaration" checks non-binding variable declarations.
• "variable-declaration-ignore-function" ignore variable declarations for non-arrow and arrow functions.
• "member-variable-declaration" checks member variable declarations.
• "object-destructuring" checks object destructuring declarations.
• "array-destructuring" checks array destructuring declarations.

Examples

"typedef": true,call-signature,parameter,member-variable-declaration

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "call-signature",
      "arrow-call-signature",
      "parameter",
      "arrow-parameter",
      "property-declaration",
      "variable-declaration",
      "variable-declaration-ignore-function",
      "member-variable-declaration",
      "object-destructuring",
      "array-destructuring"
    ]
  },
  "minLength": 0,
  "maxLength": 10
}

For more information see this page.

Rule: no-inferrable-types

Disallows explicit type declarations for variables or parameters initialized to a number, string, or boolean.

Rationale

Explicit types where they can be easily inferred by the compiler make code more verbose.

Notes

• TypeScript Only
• Has Fix

Config

Two arguments may be optionally provided:

• ignore-params allows specifying an inferrable type annotation for function params. This can be useful when combining with the typedef rule.
• ignore-properties allows specifying an inferrable type annotation for class properties.

Examples

"no-inferrable-types": true

"no-inferrable-types": true,ignore-params

"no-inferrable-types": true,ignore-params,ignore-properties

Schema

{
  "type": "array",
  "items": {
    "type": "string",
    "enum": [
      "ignore-params",
      "ignore-properties"
    ]
  },
  "minLength": 0,
  "maxLength": 2
}

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: eofline

Ensures the file ends with a newline.

Fix for single-line files is not supported.

Rationale

It is a standard convention to end files with a newline.

Notes

• Has Fix

Config

Not configurable.

Examples

"eofline": true

For more information see this page.

Rule: directive-class-suffix

Classes decorated with @Directive must have suffix "Directive" (or custom) in their name.

See more at https://angular.io/styleguide#style-02-03.

Rationale

Consistent conventions make it easy to quickly identify and reference assets of different types.

Notes

• TypeScript Only

Config

Supply a list of allowed component suffixes. Defaults to "Directive".

Examples

"directive-class-suffix": true

"directive-class-suffix": true,Directive,MySuffix

Schema

{
  "items": {
    "type": "string"
  },
  "minLength": 0,
  "type": "array"
}

For more information see this page.