pass-optional-argument

v1.34.0

warning

effort: 2m

configurable

teams+

Warns when the configured invocation does not have the configured optional argument.

This rule helps with cases when an external declaration (e.g. a pub package or SDK code) has optional parameters that you'd want to always pass. Alternatively, you might want to use this rule to gradually migrate to a required parameter.

For other cases try using the built-in required keyword to make parameters required.

⚙️ Config

Set entries (default is empty) to configure the list of entries for invocations.

Each entry is an object with 2 fields: args and name:

• Set name to configure the name of the invocation.
• Set args to configure a list of arguments that should be always passed.

analysis_options.yaml

dcm:
  rules:
    - pass-optional-argument:
        entries:
          - name: SomeClass
            args:
              - label

Example

❌ Bad:

class SomeClass {
  final int regular;
  final String? label;

  const SomeClass(this.regular, {this.label});
}

void fn() {
  // LINT: This invocation is missing required optional arguments: label. Try passing them.
  final instance = SomeClass(1);
}

✅ Good:

class SomeClass {
  final int regular;
  final String? label;

  const SomeClass(this.regular, {this.label});
}

void fn() {
  final instance = SomeClass(1, label: 'value');
}