prefer_returning_condition

v1.0.0 Warning Control Flow

This rule flags an if that returns true with a following return false (or the reverse).

Why use this rule

if (x > 0) return true; return false; is the condition itself, spelled out in three lines. return x > 0; says it once, and the reader does not have to check that the two branches really are opposites — which is exactly the check that gets skipped when one of them is later edited.

Both branches returning the same literal is a different mistake, reported by function_always_returns_same_value. A pattern case (if (x case ...)) is skipped, since it binds variables the returned expression may use.

Don’t

bool isEligible(Player player) {
  if (player.rating > 1200) {
    return true;
  }
  return false;
}

Do

bool isEligible(Player player) => player.rating > 1200;

Turning this rule off

This rule is in the opinionated preset.

To disable this rule:

many_lints.yaml

rules:
  prefer_returning_condition: false

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

Related rules

• avoid_inverted_boolean_checks — Use the opposite operator instead of negating a comparison.
• avoid_negated_conditions — State the positive case first in an if/else.
• avoid_unnecessary_negations — Collapse double negations.
• avoid_unmodified_loop_condition — A while loop whose condition the body can never change.