avoid_nested_conditional_expressions

v1.0.0WarningConfigurableControl Flow

This rule flags a conditional expression nested inside another one.

This rule is in the opinionated preset.

Why use this rule

a ? b : (c ? d : e) packs a decision tree onto one line, and the reader has to track which ? each : belongs to. A switch expression lines the branches up, and an early return removes the nesting entirely.

The outermost conditional carries the diagnostic, so one nested chain produces one report rather than one per level.

Don’t

String label(int score) =>
    score > 100 ? 'high' : (score > 50 ? 'medium' : 'low');

Do

String label(int score) => switch (score) {
  > 100 => 'high',
  > 50 => 'medium',
  _ => 'low',
};

Options

analysis_options.yaml

analysis_options.yaml

many_lints:
  rules:
    avoid_nested_conditional_expressions:
      max_depth: 2

many_lints.yaml

many_lints.yaml

rules:
  avoid_nested_conditional_expressions:
    max_depth: 2

Option	Type	Default	Description
max_depth	int	1	Maximum allowed conditional-expression nesting depth

Turning this rule off

To disable this rule:

many_lints.yaml

rules:
  avoid_nested_conditional_expressions: false

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

Related rules

• prefer_conditional_expressions — Collapse a two-way if/else into a conditional expression.
• prefer_switch_expression — Suggest converting switch statements to switch expressions.
• prefer_switch_with_enums — Use a switch instead of an if-else chain over enum constants.
• avoid_contradictory_expressions — Detect logical AND conditions that always evaluate to false.