avoid-shadowing
preset: recommended
Warns when a declaration name shadows another declaration with the same name in the current scope.
Shadowing an existing variable / parameter / field can lead to unexpected results, especially if the types of both declaration (shadowed and the new one) match.
⚙️ Config
Set ignore-static (default is false) to exclude static fields from the name scope.
Set ignore-fields (default is false) to exclude fields from the name scope.
Set ignore-parameters (default is false) to exclude parameters from the name scope.
Set ignored-names (default is empty) to ignore specific names (example).
analysis_options.yaml
dart_code_metrics:
rules:
- avoid-shadowing:
ignore-static: false
ignore-fields: false
ignore-parameters: false
ignored-names:
- some
- name
Example
❌ Bad:
class SomeClass {
final String content;
...
void method() {
// LINT: Identifier with the same name is already declared in the outer scope. Try renaming this identifier.
final content = ...;
}
// LINT: Identifier with the same name is already declared in the outer scope. Try renaming this identifier.
void anotherMethod(String content) {
...
}
void records() {
final declarations = <(int, String)>{};
var length = 0;
// LINT: Identifier with the same name is already declared in the outer scope. Try renaming this identifier.
if (declarations case Set(:final length)) {
...
}
// LINT: Identifier with the same name is already declared in the outer scope. Try renaming this identifier.
final Set(length: final length) = declarations;
}
}
✅ Good:
class SomeClass {
final String content;
...
void method() {
final localContent = ...;
}
void anotherMethod(String contentParam) {
...
}
void records() {
final declarations = <(int, String)>{};
var length = 0;
if (declarations case Set(length: final someLength)) {
...
}
final Set(length: final someLength) = declarations;
}
}
Example with "ignored-names"
Config
analysis_options.yaml
dart_code_metrics:
rules:
- avoid-shadowing:
ignored-names:
- content
✅ Good:
class SomeClass {
final String content;
...
void method() {
final content = ...; // Correct, 'content' is ignored
}
// Correct, 'content' is ignored
void anotherMethod(String content) {
...
}
}