map_keys_ordering

v1.0.0WarningConfigurableCode Organization

This rule flags a map literal whose keys are not in the configured order.

A long map literal is a lookup table, and an unordered one has to be read end to end to answer “is this key here?”. Ordering keeps a diff honest too: a new key lands in the middle where it can be seen, rather than appended at the end beside a duplicate nobody noticed.

Outside preset: pedantic, this rule reports nothing until configured. Many map literals are deliberately ordered by meaning — a config map mirroring a form’s field order, a theme map going from lightest to darkest. The pedantic preset chooses alphabetical order.

A literal containing a computed key, a spread, an if or a for is skipped entirely rather than partially ordered: ordering the rest around an unsortable entry would produce an arrangement the user cannot reach.

This rule is in the pedantic preset.

Don’t

const labels = {
  'banana': 'Banana',
  'apple': 'Apple',
  'cherry': 'Cherry',
  'date': 'Date',
  'elder': 'Elderberry',
};

Do

const labels = {
  'apple': 'Apple',
  'banana': 'Banana',
  'cherry': 'Cherry',
  'date': 'Date',
  'elder': 'Elderberry',
};

Enabling this rule

Outside preset: pedantic, enabling it by name is not enough — set order::

many_lints.yaml

rules:
  map_keys_ordering:
    order: alphabetical

Options

analysis_options.yaml

analysis_options.yaml

many_lints:
  rules:
    map_keys_ordering:
      order: alphabetical
      min_entries: 5

many_lints.yaml

many_lints.yaml

rules:
  map_keys_ordering:
    order: alphabetical
    min_entries: 5

Option	Type	Default	Description
order	string	—	alphabetical, alphabetical_case_sensitive or by_length. Unset means the rule is silent
min_entries	int	5	How many entries a literal needs before order is checked

Turning this rule off

To disable this rule:

many_lints.yaml

rules:
  map_keys_ordering: false

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

Related rules

• arguments_ordering — Keep named arguments in a configured order.
• initializers_ordering — Keep constructor initializers in field order.
• member_ordering — Keep class members in a configured order.
• parameters_ordering — Keep named parameters in a configured order.