prefer_correct_identifier_length

v1.0.0WarningConfigurableClass Naming

Flags a variable, field or parameter whose name is shorter or longer than the configured bounds — 2 to 40 characters by default.

A one-letter name outside a tiny scope forces the reader to hold a mapping the code never states, and a forty-character one is usually a sentence that belongs in a doc comment.

This rule is in the pedantic preset, and works with its defaults — no configuration needed.

Don’t

class Order {
  final int q = 0;   // LINT: one character

  // LINT: 47 characters
  final int theCompletelyUnnecessarilyVerboseLineItemTotal = 0;
}

Do

class Order {
  final int quantity = 0;

  final int lineItemTotal = 0;
}

Examples

Parameters are checked too

Locals, fields, top-level variables and parameters all go through the same bounds:

// Don't
int discount(int p, int r) => p - r;   // LINT on `p` and on `r`

// Do
int discount(int price, int rebate) => price - rebate;

The conventional short names are exempt

Loop counters, coordinates and the e of a catch clause pass out of the box — the built-in set is i j k n x y z e a b id db ui os _:

// All accepted
void render(List<String> rows) {
  for (var i = 0; i < rows.length; i++) {
    try {
      print(rows[i]);
    } catch (e) {
      print(e);
    }
  }
}

A private name is measured without its underscore

The leading _ is a modifier, not part of the name, so _id counts as two characters:

class User {
  // Accepted — `id` is two characters, and is in the built-in allow set anyway
  final int _id = 0;
}

Adding your own short names

additional_allow_names extends the built-in set. Use it for the abbreviations your codebase keeps on purpose:

analysis_options.yaml
many_lints.yaml

many_lints:
  rules:
    prefer_correct_identifier_length:
      additional_allow_names: [dx, dy, sql]

rules:
  prefer_correct_identifier_length:
    additional_allow_names: [dx, dy, sql]

// Accepted with the config above
void translate(double dx, double dy) {}

Writing allow_names: instead replaces the built-in set outright, so i and e start being reported unless you list them again. Reach for additional_allow_names unless that is what you mean.

Tightening the bounds

With min_length: 3:

// Don't — two characters is no longer enough
final ok = true;   // LINT

// Do
final isReady = true;

Options

Option	Type	Default	Description
`min_length`	int	`2`	Shortest allowed name, excluding a leading underscore
`max_length`	int	`40`	Longest allowed name, excluding a leading underscore
`allow_names`	list	(built-in set)	Names exempt from both bounds. Replaces the built-in set
`additional_allow_names`	list	`[]`	Names to add without replacing the built-in set

Known limitations

Only names you declare as storage. Variables, fields, top-level variables and parameters are checked. A method, class, getter or enum constant is not — for type names reach for prefer_correct_type_name.

No scope awareness. A two-character local in a three-line function is judged the same as a two-character field on a public API. Widen additional_allow_names rather than lowering min_length when only a few names are the exception.

Enabling this rule

This rule is in the pedantic preset, so it is enabled by preset: pedantic or by name:

rules:
  prefer_correct_identifier_length:
    enabled: true

Turning this rule off

To disable this rule:

rules:
  prefer_correct_identifier_length: false

To keep the rule on but skip certain paths, use per-rule exclude.

match_class_name_pattern — Match class names against a regular expression.
prefer_correct_type_name — Keep type names within a sensible length and correctly capitalised.
use_class_prefix — Require a name prefix for classes deriving from a configured type.
use_class_suffix — Require a name suffix for classes deriving from a configured type.