Fix subtype test in UnnecessaryMethodReference

`ASTHelpers.isSubtype` does erasure, which isn't what we want here. Fixes #2117 PiperOrigin-RevId: 352601858
google · Jan 19, 2021 · be94375 · be94375
1 parent d847960
commit be94375
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Showing 2 changed files with 16 additions and 2 deletions.
diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/UnnecessaryMethodReference.java b/core/src/main/java/com/google/errorprone/bugpatterns/UnnecessaryMethodReference.java
@@ -21,7 +21,6 @@
 import static com.google.errorprone.util.ASTHelpers.getReceiver;
 import static com.google.errorprone.util.ASTHelpers.getSymbol;
 import static com.google.errorprone.util.ASTHelpers.getType;
-import static com.google.errorprone.util.ASTHelpers.isSubtype;
 import static com.google.errorprone.util.ASTHelpers.targetType;
 import static javax.lang.model.element.Modifier.ABSTRACT;
 
@@ -74,7 +73,7 @@ public Description matchMemberReference(MemberReferenceTree tree, VisitorState s
         && ((IdentifierTree) receiver).getName().contentEquals("super")) {
       return NO_MATCH;
     }
-    if (!isSubtype(getType(receiver), targetType.type(), state)) {
+    if (!state.getTypes().isSubtype(getType(receiver), targetType.type())) {
       return NO_MATCH;
     }
     MethodSymbol symbol = getSymbol(tree);

diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryMethodReferenceTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryMethodReferenceTest.java
@@ -183,4 +183,19 @@ public void ignoreSuper() {
             "}")
         .doTest();
   }
+
+  @Test
+  public void subType() {
+    helper
+        .addSourceLines(
+            "T.java",
+            "import java.util.function.Consumer;",
+            "abstract class T {",
+            "  void f(Consumer<String> c) {}",
+            "  void g(Consumer<Object> c) {",
+            "    f(c::accept);",
+            "  }",
+            "}")
+        .doTest();
+  }
 }