@typescript-eslint/eslint-plugin/docs/rules/member-ordering.md

# `member-ordering`

Require a consistent member declaration order.

A consistent ordering of fields, methods and constructors can make interfaces, type literals, classes and class expressions easier to read, navigate, and edit.

## Rule Details

This rule aims to standardize the way class declarations, class expressions, interfaces and type literals are structured and ordered.

## Options

```ts
interface Options {
  default?: OrderConfig;
  classes?: OrderConfig;
  classExpressions?: OrderConfig;
  interfaces?: OrderConfig;
  typeLiterals?: OrderConfig;
}

type OrderConfig = MemberType[] | SortedOrderConfig | 'never';

interface SortedOrderConfig {
  memberTypes?: MemberType[] | 'never';
  order: 'alphabetically' | 'alphabetically-case-insensitive' | 'as-written';
}

// See below for the more specific MemberType strings
type MemberType = string | string[];
```

You can configure `OrderConfig` options for:

- **`default`**: all constructs (used as a fallback)
- **`classes`**?: override ordering specifically for classes
- **`classExpressions`**?: override ordering specifically for class expressions
- **`interfaces`**?: override ordering specifically for interfaces
- **`typeLiterals`**?: override ordering specifically for type literals

The `OrderConfig` settings for each kind of construct may configure sorting on one or both two levels:

- **`memberType`**: organizing on member type groups such as methods vs. properties
- **`order`**: organizing based on member names, such as alphabetically

### Groups

You can define many different groups based on different attributes of members.
The supported member attributes are, in order:

- **Accessibility** (`'public' | 'protected' | 'private'`)
- **Decoration** (`'decorated'`): Whether the member has an explicit accessibility decorator
- **Kind** (`'call-signature' | 'constructor' | 'field' | 'get' | 'method' | 'set' | 'signature'`)

Member attributes may be joined with a `'-'` to combine into more specific groups.
For example, `'public-field'` would come before `'private-field'`.

### Default configuration

The default configuration looks as follows:

```jsonc
{
  "default": [
    // Index signature
    "signature",

    // Fields
    "public-static-field",
    "protected-static-field",
    "private-static-field",

    "public-decorated-field",
    "protected-decorated-field",
    "private-decorated-field",

    "public-instance-field",
    "protected-instance-field",
    "private-instance-field",

    "public-abstract-field",
    "protected-abstract-field",
    "private-abstract-field",

    "public-field",
    "protected-field",
    "private-field",

    "static-field",
    "instance-field",
    "abstract-field",

    "decorated-field",

    "field",

    // Constructors
    "public-constructor",
    "protected-constructor",
    "private-constructor",

    "constructor",

    // Getters
    "public-static-get",
    "protected-static-get",
    "private-static-get",

    "public-decorated-get",
    "protected-decorated-get",
    "private-decorated-get",

    "public-instance-get",
    "protected-instance-get",
    "private-instance-get",

    "public-abstract-get",
    "protected-abstract-get",
    "private-abstract-get",

    "public-get",
    "protected-get",
    "private-get",

    "static-get",
    "instance-get",
    "abstract-get",

    "decorated-get",

    "get",

    // Setters
    "public-static-set",
    "protected-static-set",
    "private-static-set",

    "public-decorated-set",
    "protected-decorated-set",
    "private-decorated-set",

    "public-instance-set",
    "protected-instance-set",
    "private-instance-set",

    "public-abstract-set",
    "protected-abstract-set",
    "private-abstract-set",

    "public-set",
    "protected-set",
    "private-set",

    "static-set",
    "instance-set",
    "abstract-set",

    "decorated-set",

    "set",

    // Methods
    "public-static-method",
    "protected-static-method",
    "private-static-method",

    "public-decorated-method",
    "protected-decorated-method",
    "private-decorated-method",

    "public-instance-method",
    "protected-instance-method",
    "private-instance-method",

    "public-abstract-method",
    "protected-abstract-method",
    "private-abstract-method",

    "public-method",
    "protected-method",
    "private-method",

    "static-method",
    "instance-method",
    "abstract-method",

    "decorated-method",

    "method"
  ]
}
```

:::note
The default configuration contains member group types which contain other member types.
This is intentional to provide better error messages.
:::

:::tip
By default, the members are not sorted.
If you want to sort them alphabetically, you have to provide a custom configuration.
:::

## Examples

### General Order on All Constructs

This config specifies the order for all constructs.
It ignores member types other than signatures, methods, constructors, and fields.
It also ignores accessibility and scope.

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "default": ["signature", "method", "constructor", "field"] }
    ]
  }
}
```

<!--tabs-->

#### ❌ Incorrect

```ts
interface Foo {
  B: string; // -> field

  new (); // -> constructor

  A(): void; // -> method

  [Z: string]: any; // -> signature
}
```

```ts
type Foo = {
  B: string; // -> field

  // no constructor

  A(): void; // -> method

  // no signature
};
```

```ts
class Foo {
  private C: string; // -> field
  public D: string; // -> field
  protected static E: string; // -> field

  constructor() {} // -> constructor

  public static A(): void {} // -> method
  public B(): void {} // -> method

  [Z: string]: any; // -> signature
}
```

```ts
const Foo = class {
  private C: string; // -> field
  public D: string; // -> field

  constructor() {} // -> constructor

  public static A(): void {} // -> method
  public B(): void {} // -> method

  [Z: string]: any; // -> signature

  protected static E: string; // -> field
};
```

#### ✅ Correct

```ts
interface Foo {
  [Z: string]: any; // -> signature

  A(): void; // -> method

  new (); // -> constructor

  B: string; // -> field
}
```

```ts
type Foo = {
  // no signature

  A(): void; // -> method

  // no constructor

  B: string; // -> field
};
```

```ts
class Foo {
  [Z: string]: any; // -> signature

  public static A(): void {} // -> method
  public B(): void {} // -> method

  constructor() {} // -> constructor

  private C: string; // -> field
  public D: string; // -> field
  protected static E: string; // -> field
}
```

```ts
const Foo = class {
  [Z: string]: any; // -> signature

  public static A(): void {} // -> method
  public B(): void {} // -> method

  constructor() {} // -> constructor

  private C: string; // -> field
  public D: string; // -> field
  protected static E: string; // -> field
};
```

### Classes

#### Public Instance Methods Before Public Static Fields

This config specifies that public instance methods should come first before public static fields.
Everything else can be placed anywhere.
It doesn't apply to interfaces or type literals as accessibility and scope are not part of them.

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "default": ["public-instance-method", "public-static-field"] }
    ]
  }
}
```

<!--tabs-->

##### ❌ Incorrect

```ts
class Foo {
  private C: string; // (irrelevant)

  public D: string; // (irrelevant)

  public static E: string; // -> public static field

  constructor() {} // (irrelevant)

  public static A(): void {} // (irrelevant)

  [Z: string]: any; // (irrelevant)

  public B(): void {} // -> public instance method
}
```

```ts
const Foo = class {
  private C: string; // (irrelevant)

  [Z: string]: any; // (irrelevant)

  public static E: string; // -> public static field

  public D: string; // (irrelevant)

  constructor() {} // (irrelevant)

  public static A(): void {} // (irrelevant)

  public B(): void {} // -> public instance method
};
```

##### ✅ Correct

```ts
class Foo {
  public B(): void {} // -> public instance method

  private C: string; // (irrelevant)

  public D: string; // (irrelevant)

  public static E: string; // -> public static field

  constructor() {} // (irrelevant)

  public static A(): void {} // (irrelevant)

  [Z: string]: any; // (irrelevant)
}
```

```ts
const Foo = class {
  public B(): void {} // -> public instance method

  private C: string; // (irrelevant)

  [Z: string]: any; // (irrelevant)

  public D: string; // (irrelevant)

  constructor() {} // (irrelevant)

  public static A(): void {} // (irrelevant)

  public static E: string; // -> public static field
};
```

#### Static Fields Before Instance Fields

This config specifies that static fields should come before instance fields, with public static fields first.
It doesn't apply to interfaces or type literals as accessibility and scope are not part of them.

```jsonc
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "default": ["public-static-field", "static-field", "instance-field"] }
    ]
  }
}
```

<!--tabs-->

##### ❌ Incorrect

```ts
class Foo {
  private E: string; // -> instance field

  private static B: string; // -> static field
  protected static C: string; // -> static field
  private static D: string; // -> static field

  public static A: string; // -> public static field

  [Z: string]: any; // (irrelevant)
}
```

```ts
const foo = class {
  public T(): void {} // method (irrelevant)

  private static B: string; // -> static field

  constructor() {} // constructor (irrelevant)

  private E: string; // -> instance field

  protected static C: string; // -> static field
  private static D: string; // -> static field

  [Z: string]: any; // signature (irrelevant)

  public static A: string; // -> public static field
};
```

##### ✅ Correct

```ts
class Foo {
  public static A: string; // -> public static field

  private static B: string; // -> static field
  protected static C: string; // -> static field
  private static D: string; // -> static field

  private E: string; // -> instance field

  [Z: string]: any; // (irrelevant)
}
```

```ts
const foo = class {
  [Z: string]: any; // -> signature (irrelevant)

  public static A: string; // -> public static field

  constructor() {} // -> constructor (irrelevant)

  private static B: string; // -> static field
  protected static C: string; // -> static field
  private static D: string; // -> static field

  private E: string; // -> instance field

  public T(): void {} // -> method (irrelevant)
};
```

#### Class Declarations

This config only specifies an order for classes: methods, then the constructor, then fields.
It does not apply to class expressions (use `classExpressions` for them).
Default settings will be used for class declarations and all other syntax constructs other than class declarations.

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "classes": ["method", "constructor", "field"] }
    ]
  }
}
```

<!--tabs-->

##### ❌ Incorrect

```ts
class Foo {
  private C: string; // -> field
  public D: string; // -> field
  protected static E: string; // -> field

  constructor() {} // -> constructor

  public static A(): void {} // -> method
  public B(): void {} // -> method
}
```

##### ✅ Correct

```ts
class Foo {
  public static A(): void {} // -> method
  public B(): void {} // -> method

  constructor() {} // -> constructor

  private C: string; // -> field
  public D: string; // -> field
  protected static E: string; // -> field
}
```

#### Class Expressions

This config only specifies an order for classes expressions: methods, then the constructor, then fields.
It does not apply to class declarations (use `classes` for them).
Default settings will be used for class declarations and all other syntax constructs other than class expressions.

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "classExpressions": ["method", "constructor", "field"] }
    ]
  }
}
```

<!--tabs-->

##### ❌ Incorrect

```ts
const foo = class {
  private C: string; // -> field
  public D: string; // -> field
  protected static E: string; // -> field

  constructor() {} // -> constructor

  public static A(): void {} // -> method
  public B(): void {} // -> method
};
```

##### ✅ Correct

```ts
const foo = class {
  public static A(): void {} // -> method
  public B(): void {} // -> method

  constructor() {} // -> constructor

  private C: string; // -> field
  public D: string; // -> field
  protected static E: string; // -> field
};
```

### Interfaces

This config only specifies an order for interfaces: signatures, then methods, then constructors, then fields.
It does not apply to type literals (use `typeLiterals` for them).
Default settings will be used for type literals and all other syntax constructs other than class expressions.

:::note
These member types are the only ones allowed for `interfaces`.
:::

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "interfaces": ["signature", "method", "constructor", "field"] }
    ]
  }
}
```

<!--tabs-->

#### ❌ Incorrect

```ts
interface Foo {
  B: string; // -> field

  new (); // -> constructor

  A(): void; // -> method

  [Z: string]: any; // -> signature
}
```

#### ✅ Correct

```ts
interface Foo {
  [Z: string]: any; // -> signature

  A(): void; // -> method

  new (); // -> constructor

  B: string; // -> field
}
```

### Type Literals

This config only specifies an order for type literals: signatures, then methods, then constructors, then fields.
It does not apply to interfaces (use `interfaces` for them).
Default settings will be used for interfaces and all other syntax constructs other than class expressions.

:::note
These member types are the only ones allowed for `typeLiterals`.
:::

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "typeLiterals": ["signature", "method", "constructor", "field"] }
    ]
  }
}
```

<!--tabs-->

#### ❌ Incorrect

```ts
type Foo = {
  B: string; // -> field

  A(): void; // -> method

  new (); // -> constructor

  [Z: string]: any; // -> signature
};
```

#### ✅ Correct

```ts
type Foo = {
  [Z: string]: any; // -> signature

  A(): void; // -> method

  new (); // -> constructor

  B: string; // -> field
};
```

### Sorting Options

#### Sorting Alphabetically Within Member Groups

This config specifies that within each `memberTypes` group, members are in an alphabetic case-sensitive order.
You can copy and paste the default order from [Default Configuration](#default-configuration).

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      {
        "default": {
          "memberTypes": [
            /* <Default Order> */
          ],
          "order": "alphabetically"
        }
      }
    ]
  }
}
```

<!--tabs-->

##### ❌ Incorrect

```ts
interface Foo {
  a: x;
  B: x;
  c: x;

  B(): void;
  c(): void;
  a(): void;
}
```

##### ✅ Correct

```ts
interface Foo {
  B: x;
  a: x;
  c: x;

  B(): void;
  a(): void;
  c(): void;
}
```

#### Sorting Alphabetically Case Insensitive Within Member Groups

This config specifies that within each `memberTypes` group, members are in an alphabetic case-sensitive order.
You can copy and paste the default order from [Default Configuration](#default-configuration).

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      {
        "default": {
          "memberTypes": [
            /* <Default Order> */
          ],
          "order": "alphabetically-case-insensitive"
        }
      }
    ]
  }
}
```

<!--tabs-->

##### ❌ Incorrect

```ts
interface Foo {
  B: x;
  a: x;
  c: x;

  B(): void;
  c(): void;
  a(): void;
}
```

##### ✅ Correct

```ts
interface Foo {
  a: x;
  B: x;
  c: x;

  a(): void;
  B(): void;
  c(): void;
}
```

#### Sorting Alphabetically Ignoring Member Groups

This config specifies that members are all sorted in an alphabetic case-sensitive order.
It ignores any member group types completely by specifying `"never"` for `memberTypes`.

```jsonc
// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/member-ordering": [
      "error",
      { "default": { "memberTypes": "never", "order": "alphabetically" } }
    ]
  }
}
```

<!--tabs-->

##### ❌ Incorrect

```ts
interface Foo {
  static c = 0;
  b(): void;
  a: boolean;

  [a: string]: number; // Order doesn't matter (no sortable identifier)
  new (): Bar; // Order doesn't matter (no sortable identifier)
  (): Baz; // Order doesn't matter (no sortable identifier)
}
```

##### ✅ Correct

```ts
interface Foo {
  a: boolean;
  b(): void;
  static c = 0;

  [a: string]: number; // Order doesn't matter (no sortable identifier)
  new (): Bar; // Order doesn't matter (no sortable identifier)
  (): Baz; // Order doesn't matter (no sortable identifier)
}
```

## All Supported Options

### Member Types (Granular Form)

There are multiple ways to specify the member types.
The most explicit and granular form is the following:

```jsonc
[
  // Index signature
  "signature",

  // Fields
  "public-static-field",
  "protected-static-field",
  "private-static-field",
  "public-decorated-field",
  "protected-decorated-field",
  "private-decorated-field",
  "public-instance-field",
  "protected-instance-field",
  "private-instance-field",
  "public-abstract-field",
  "protected-abstract-field",
  "private-abstract-field",

  // Constructors
  "public-constructor",
  "protected-constructor",
  "private-constructor",

  // Getters
  "public-static-get",
  "protected-static-get",
  "private-static-get",

  "public-decorated-get",
  "protected-decorated-get",
  "private-decorated-get",

  "public-instance-get",
  "protected-instance-get",
  "private-instance-get",

  "public-abstract-get",
  "protected-abstract-get",
  "private-abstract-get",

  "public-get",
  "protected-get",
  "private-get",

  "static-get",
  "instance-get",
  "abstract-get",

  "decorated-get",

  "get",

  // Setters
  "public-static-set",
  "protected-static-set",
  "private-static-set",

  "public-decorated-set",
  "protected-decorated-set",
  "private-decorated-set",

  "public-instance-set",
  "protected-instance-set",
  "private-instance-set",

  "public-abstract-set",
  "protected-abstract-set",
  "private-abstract-set",

  "public-set",
  "protected-set",
  "private-set",

  "static-set",
  "instance-set",
  "abstract-set",

  "decorated-set",

  "set",

  // Methods
  "public-static-method",
  "protected-static-method",
  "private-static-method",
  "public-decorated-method",
  "protected-decorated-method",
  "private-decorated-method",
  "public-instance-method",
  "protected-instance-method",
  "private-instance-method",
  "public-abstract-method",
  "protected-abstract-method",
  "private-abstract-method"
]
```

:::note
If you only specify some of the possible types, the non-specified ones can have any particular order.
This means that they can be placed before, within or after the specified types and the linter won't complain about it.
:::

### Member Group Types (With Accessibility, Ignoring Scope)

It is also possible to group member types by their accessibility (`static`, `instance`, `abstract`), ignoring their scope.

```jsonc
[
  // Index signature
  // No accessibility for index signature.

  // Fields
  "public-field", // = ["public-static-field", "public-instance-field"]
  "protected-field", // = ["protected-static-field", "protected-instance-field"]
  "private-field", // = ["private-static-field", "private-instance-field"]

  // Constructors
  // Only the accessibility of constructors is configurable. See below.

  // Getters
  "public-get", // = ["public-static-get", "public-instance-get"]
  "protected-get", // = ["protected-static-get", "protected-instance-get"]
  "private-get", // = ["private-static-get", "private-instance-get"]

  // Setters
  "public-set", // = ["public-static-set", "public-instance-set"]
  "protected-set", // = ["protected-static-set", "protected-instance-set"]
  "private-set", // = ["private-static-set", "private-instance-set"]

  // Methods
  "public-method", // = ["public-static-method", "public-instance-method"]
  "protected-method", // = ["protected-static-method", "protected-instance-method"]
  "private-method" // = ["private-static-method", "private-instance-method"]
]
```

### Member Group Types (With Accessibility and a Decorator)

It is also possible to group methods or fields with a decorator separately, optionally specifying
their accessibility.

```jsonc
[
  // Index signature
  // No decorators for index signature.

  // Fields
  "public-decorated-field",
  "protected-decorated-field",
  "private-decorated-field",

  "decorated-field", // = ["public-decorated-field", "protected-decorated-field", "private-decorated-field"]

  // Constructors
  // There are no decorators for constructors.

  // Getters
  "public-decorated-get",
  "protected-decorated-get",
  "private-decorated-get",

  "decorated-get" // = ["public-decorated-get", "protected-decorated-get", "private-decorated-get"]

  // Setters
  "public-decorated-set",
  "protected-decorated-set",
  "private-decorated-set",

  "decorated-set" // = ["public-decorated-set", "protected-decorated-set", "private-decorated-set"]

  // Methods
  "public-decorated-method",
  "protected-decorated-method",
  "private-decorated-method",

  "decorated-method" // = ["public-decorated-method", "protected-decorated-method", "private-decorated-method"]
]
```

### Member Group Types (With Scope, Ignoring Accessibility)

Another option is to group the member types by their scope (`public`, `protected`, `private`), ignoring their accessibility.

```jsonc
[
  // Index signature
  // No scope for index signature.

  // Fields
  "static-field", // = ["public-static-field", "protected-static-field", "private-static-field"]
  "instance-field", // = ["public-instance-field", "protected-instance-field", "private-instance-field"]
  "abstract-field", // = ["public-abstract-field", "protected-abstract-field", "private-abstract-field"]

  // Constructors
  "constructor", // = ["public-constructor", "protected-constructor", "private-constructor"]

  // Getters
  "static-get", // = ["public-static-get", "protected-static-get", "private-static-get"]
  "instance-get", // = ["public-instance-get", "protected-instance-get", "private-instance-get"]
  "abstract-get" // = ["public-abstract-get", "protected-abstract-get", "private-abstract-get"]

  // Setters
  "static-set", // = ["public-static-set", "protected-static-set", "private-static-set"]
  "instance-set", // = ["public-instance-set", "protected-instance-set", "private-instance-set"]
  "abstract-set" // = ["public-abstract-set", "protected-abstract-set", "private-abstract-set"]

  // Methods
  "static-method", // = ["public-static-method", "protected-static-method", "private-static-method"]
  "instance-method", // = ["public-instance-method", "protected-instance-method", "private-instance-method"]
  "abstract-method" // = ["public-abstract-method", "protected-abstract-method", "private-abstract-method"]
]
```

### Member Group Types (With Scope and Accessibility)

The third grouping option is to ignore both scope and accessibility.

```jsonc
[
  // Index signature
  // No grouping for index signature.

  // Fields
  "field", // = ["public-static-field", "protected-static-field", "private-static-field", "public-instance-field", "protected-instance-field", "private-instance-field",
  //              "public-abstract-field", "protected-abstract-field", private-abstract-field"]

  // Constructors
  // Only the accessibility of constructors is configurable.

  // Getters
  "get" // = ["public-static-get", "protected-static-get", "private-static-get", "public-instance-get", "protected-instance-get", "private-instance-get",
  //                "public-abstract-get", "protected-abstract-get", "private-abstract-get"]

  // Setters
  "set" // = ["public-static-set", "protected-static-set", "private-static-set", "public-instance-set", "protected-instance-set", "private-instance-set",
  //                "public-abstract-set", "protected-abstract-set", "private-abstract-set"]

  // Methods
  "method" // = ["public-static-method", "protected-static-method", "private-static-method", "public-instance-method", "protected-instance-method", "private-instance-method",
  //                "public-abstract-method", "protected-abstract-method", "private-abstract-method"]
]
```

### Grouping Different Member Types at the Same Rank

It is also possible to group different member types at the same rank.

```jsonc
[
  // Index signature
  "signature",

  // Fields
  "field",

  // Constructors
  "constructor",

  // Getters and Setters at the same rank
  ["get", "set"],

  // Methods
  "method"
]
```

## When Not To Use It

If you don't care about the general order of your members, then you will not need this rule.

## Related To

- TSLint: [member-ordering](https://palantir.github.io/tslint/rules/member-ordering/)

## Attributes

- Configs:
  - [ ] ✅ Recommended
  - [ ] 🔒 Strict
- [ ] 🔧 Fixable
- [ ] 💭 Requires type information