falconGitHub

prefer-correct-type-name

Same as prefer-correct-type-name in Dart Code Metrics

Group
Style
Path
lint/style/prefer-correct-type-name
Default
Off, opt in
Origin
Dart Code Metrics
Rule
344 of 512

Flags type declarations whose name is not well-formed UpperCamelCase.

Consistent UpperCamelCase type names are a core Dart convention that keeps types visually distinct from members and values. A name is accepted only when it starts with an uppercase ASCII letter, contains no $, and — after a single leading underscore is stripped — is between 3 and 40 characters long; anything else is reported. The check covers classes, mixins, mixin classes, enums, named extensions, extension types, and type aliases. It inspects the declared name's spelling only, so it does not enforce interior capitalization such as an acronym written in all caps.

Invalid

example.dartdart
// Lowercase names should be flagged
class foo {}

// Too short (only 2 chars)
class Ab {}

// Lowercase enum
enum color { red, green }

// Too short mixin (2 chars)
mixin mx {}

// Too short typedef (2 chars)
typedef cb = void Function();

// Contains dollar sign
class Foo$Bar {}

// Too long (41 chars)
class VeryLongNameThatExceedsTheFortyCharacterLimit {}

// Extension with name that's too short
extension st on String {}

// ExtensionType with non-uppercase name
extension type val(int x) {}
Type name `foo` should be in `UpperCamelCase` and between 3 and 40 characters.
1// Lowercase names should be flagged
2class foo {}
Type name `Ab` should be in `UpperCamelCase` and between 3 and 40 characters.
4// Too short (only 2 chars)
5class Ab {}
Type name `color` should be in `UpperCamelCase` and between 3 and 40 characters.
7// Lowercase enum
8enum color { red, green }
Type name `mx` should be in `UpperCamelCase` and between 3 and 40 characters.
10// Too short mixin (2 chars)
11mixin mx {}
Type name `cb` should be in `UpperCamelCase` and between 3 and 40 characters.
13// Too short typedef (2 chars)
14typedef cb = void Function();
Type name `Foo$Bar` should be in `UpperCamelCase` and between 3 and 40 characters.
16// Contains dollar sign
17class Foo$Bar {}
Type name `VeryLongNameThatExceedsTheFortyCharacterLimit` should be in `UpperCamelCase` and between 3 and 40 characters.
19// Too long (41 chars)
20class VeryLongNameThatExceedsTheFortyCharacterLimit {}
Type name `st` should be in `UpperCamelCase` and between 3 and 40 characters.
22// Extension with name that's too short
23extension st on String {}
Type name `val` should be in `UpperCamelCase` and between 3 and 40 characters.
25// ExtensionType with non-uppercase name
26extension type val(int x) {}

Valid

example.dartdart
// Standard class with UpperCamelCase
class Foo {}

// Longer descriptive name
class HttpClient {}

// Private class with underscore prefix (stripped, "Internal" is 8 chars and uppercase)
class _Internal {}

// Enum with proper case
enum Color { red, green }

// Mixin with proper case
mixin Loggable {}

// TypeAlias with proper case
typedef Callback = void Function();

// ExtensionType with proper name
extension type IntId(int value) {}

// Extension without name (should not be checked)
extension on String {}

// Extension with a proper name
extension StringX on String {}

// Edge case: exactly 3 chars (minimum)
class Foo {}

// Edge case: exactly 40 chars
class HttpClientWithVeryDetailedNameHere {}

// Private type with valid stripped name
class _HttpClientInternal {}

Configure prefer-correct-type-name

Set its severity in falcon.json. See the configuration guide.

falcon.jsonjson
{
  "linter": {
    "rules": {
      "style": {
        "prefer-correct-type-name": "error"
      }
    }
  }
}

Or silence one occurrence with a suppression comment; the reason is required.

example.dartdart
// falcon-ignore lint/style/prefer-correct-type-name: <reason>
  • prefer-dedicated-media-query-methodsprefer_dedicated_media_query_methodsrecommendedflutter

    Flags MediaQuery.of(context).size access in favor of MediaQuery.sizeOf.

  • prefer-double-quotesprefer_double_quotes

    Flags single-quoted string literals that could use double quotes without needing an escape.

  • prefer-early-return

    Flags a trailing if that wraps multiple statements in a void function.

  • prefer-equatable-mixinequatable

    Prefer EquatableMixin to directly extending package:equatable's Equatable.

  • prefer-final-fieldsprefer_final_fieldsrecommended

    Flags a private field that is initialized but never reassigned, so it could be final (prefer-final-fields, adopted from package:lints).

  • prefer-final-in-for-eachprefer_final_in_for_eachrecommended

    Prefer final for a for-each loop variable that is never reassigned.

  • prefer-final-localsprefer_final_localsrecommended

    Prefer final for local variable declarations that are never reassigned.

  • prefer-final-parametersprefer_final_parameters

    Prefer final for parameters that are never reassigned.