UnnecessaryMethodReference: drop the requirement that the offending m…

…ethod reference must be a method argument. This lets us refactor variable assignments too. I'm not sure what the rationale for this restriction was, given no tests fail having removed it. PiperOrigin-RevId: 631745347
google · May 8, 2024 · af521ef · af521ef
1 parent 93861b8
commit af521ef
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Showing 2 changed files with 17 additions and 4 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
@@ -41,7 +41,6 @@
 import com.sun.source.tree.IdentifierTree;
 import com.sun.source.tree.MemberReferenceTree;
 import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
-import com.sun.source.tree.MethodInvocationTree;
 import com.sun.tools.javac.code.Scope;
 import com.sun.tools.javac.code.Symbol;
 import com.sun.tools.javac.code.Symbol.MethodSymbol;
@@ -59,9 +58,6 @@ public Description matchMemberReference(MemberReferenceTree tree, VisitorState s
     if (!tree.getMode().equals(ReferenceMode.INVOKE)) {
       return NO_MATCH;
     }
-    if (!(state.getPath().getParentPath().getLeaf() instanceof MethodInvocationTree)) {
-      return NO_MATCH;
-    }
     TargetType targetType = targetType(state);
     if (targetType == null) {
       return NO_MATCH;

diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryMethodReferenceTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryMethodReferenceTest.java
@@ -249,4 +249,21 @@ public void range_isGuavaPredicate() {
             "}")
         .doTest();
   }
+
+  @Test
+  public void listToIterator() {
+    helper
+        .addSourceLines(
+            "T.java",
+            "import com.google.common.collect.ImmutableList;",
+            "import java.util.List;",
+            "abstract class T {",
+            "  void test() {",
+            "    List<Integer> x = ImmutableList.of(1, 2);",
+            "    // BUG: Diagnostic contains:",
+            "    Iterable<Integer> xi = x::iterator;",
+            "  }",
+            "}")
+        .doTest();
+  }
 }