unrelated_type_equality_checks
對不相關型別的引用呼叫相等運算子 ==。
詳細資訊
#不要 比較不相關型別的引用是否相等。
比較不同型別（彼此非子型別）的引用是否相等，很可能返回 false，這可能並非程式設計者的意圖。
package:fixnum 中的 Int64 和 Int32 允許與 int 比較，前提是 int 在右側。Linter 將此視為特例。
不良示例
dart
void someFunction() {
var x = '1';
if (x == 1) print('someFunction'); // LINT
}不良示例
dart
void someFunction1() {
String x = '1';
if (x == 1) print('someFunction1'); // LINT
}不良示例
dart
void someFunction13(DerivedClass2 instance) {
var other = DerivedClass3();
if (other == instance) print('someFunction13'); // LINT
}
class ClassBase {}
class DerivedClass1 extends ClassBase {}
abstract class Mixin {}
class DerivedClass2 extends ClassBase with Mixin {}
class DerivedClass3 extends ClassBase implements Mixin {}良好示例
dart
void someFunction2() {
var x = '1';
var y = '2';
if (x == y) print(someFunction2); // OK
}良好示例
dart
void someFunction3() {
for (var i = 0; i < 10; i++) {
if (i == 0) print(someFunction3); // OK
}
}良好示例
dart
void someFunction4() {
var x = '1';
if (x == null) print(someFunction4); // OK
}良好示例
dart
void someFunction7() {
List someList;
if (someList.length == 0) print('someFunction7'); // OK
}良好示例
dart
void someFunction8(ClassBase instance) {
DerivedClass1 other;
if (other == instance) print('someFunction8'); // OK
}良好示例
dart
void someFunction10(unknown) {
var what = unknown - 1;
for (var index = 0; index < unknown; index++) {
if (what == index) print('someFunction10'); // OK
}
}良好示例
dart
void someFunction11(Mixin instance) {
var other = DerivedClass2();
if (other == instance) print('someFunction11'); // OK
if (other != instance) print('!someFunction11'); // OK
}
class ClassBase {}
abstract class Mixin {}
class DerivedClass2 extends ClassBase with Mixin {}啟用
#要啟用 unrelated_type_equality_checks 規則，請在你的 analysis_options.yaml 檔案中的 linter > rules 下新增 unrelated_type_equality_checks
analysis_options.yaml
yaml
linter:
rules:
- unrelated_type_equality_checks如果你使用 YAML 對映語法配置 Linter 規則，請在 linter > rules 下新增 unrelated_type_equality_checks: true
analysis_options.yaml
yaml
linter:
rules:
unrelated_type_equality_checks: true