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prefer-conditional-expressions

added in: 1.6.0
style
⚙️🛠
Free+

Recommends using a conditional expression instead of assigning to the same variable or returning a value in each branch of an if statement.

⚙️ Config​

Set ignore-nested (default is false) to ignore cases with multiple nested conditional expressions (example).

analysis_options.yaml
dart_code_metrics:
  rules:
    - prefer-conditional-expressions:
        ignore-nested: false

Example​

❌ Bad:

int a = 0;

// LINT: Prefer rewriting this 'if' statement into a conditional expression.
if (a > 0) {
  a = 1;
} else {
  a = 2;
}

// LINT: Prefer rewriting this 'if' statement into a conditional expression.
if (a > 0) a = 1;
else a = 2;

int function() {
  // LINT: Prefer rewriting this 'if' statement into a conditional expression.
  if (a == 1) {
    return 0;
  } else {
    return 1;
  }

  // LINT: Prefer rewriting this 'if' statement into a conditional expression.
  if (a == 2) return 0;
  else return 1;
}

✅ Good:

int a = 0;

a = a > 0 ? 1 : 2;

int function() {
  return a == 2 ? 0 : 1;
}

Example with "ignore-nested"​

Config
analysis_options.yaml
dart_code_metrics:
  rules:
    - prefer-conditional-expressions:
        ignore-nested: true

✅ Good:

if (condition) { // Correct, uses a conditional expression inside
  value = !another ? 'new' : 'old';
} else {
  value = null;
}