Fix false negative in prefer_contains (dart-archive/linter#2830)

* Fix false negative in `prefer_contains`

* restrict for TypeParameterType

* use `typeForInterfaceCheck`

* Rename to `typeToCheck`

Author: asashour

lib/src/extensions.dart

@@ -187,11 +187,14 @@ extension DartTypeExtension on DartType? {
     bool isAnyInterface(InterfaceType i) =>
         definitions.any((d) => i.isSameAs(d.name, d.library));
 
-    var self = this;
-    if (self is InterfaceType) {
-      return isAnyInterface(self) ||
-          !self.element.isSynthetic &&
-              self.element.allSupertypes.any(isAnyInterface);
+    var typeToCheck = this;
+    if (typeToCheck is TypeParameterType) {
+      typeToCheck = typeToCheck.typeForInterfaceCheck;
+    }
+    if (typeToCheck is InterfaceType) {
+      return isAnyInterface(typeToCheck) ||
+          !typeToCheck.element.isSynthetic &&
+              typeToCheck.element.allSupertypes.any(isAnyInterface);
     } else {
       return false;
     }

test_data/rules/prefer_contains.dart

@@ -82,3 +82,9 @@ testOperators() {
   0 > [].indexOf(1); // LINT
   0 >= [].indexOf(1); // OK
 }
+
+bool f<T extends List<int>>(T list) =>
+  list.indexOf(1) < 0; // LINT
+
+bool g<T>(T list) =>
+  list is List<int> && list.indexOf(1) < 0; // LINT