Adding test case and relevant logic to handle when a returned diamond…

… operator object is calling a method
uber · Nov 9, 2023 · 95d3e8e · 95d3e8e
1 parent 5aeb32c
commit 95d3e8e
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diff --git a/nullaway/src/main/java/com/uber/nullaway/GenericsChecks.java b/nullaway/src/main/java/com/uber/nullaway/GenericsChecks.java
@@ -787,6 +787,18 @@ public static Nullness getGenericReturnNullnessAtInvocation(
     if (!(tree.getMethodSelect() instanceof MemberSelectTree) || invokedMethodSymbol.isStatic()) {
       return Nullness.NONNULL;
     }
+    Tree expressionTree = ((MemberSelectTree) tree.getMethodSelect()).getExpression();
+    if (expressionTree instanceof NewClassTree
+        && ((NewClassTree) expressionTree).getIdentifier() instanceof ParameterizedTypeTree) {
+      ParameterizedTypeTree paramTypedTree =
+          (ParameterizedTypeTree) ((NewClassTree) expressionTree).getIdentifier();
+      // The case of having a diamond operator
+      if (paramTypedTree.getTypeArguments().isEmpty()) {
+        // bail out
+        // TODO: support diamond operators
+        return Nullness.NONNULL;
+      }
+    }
     Type methodReceiverType =
         castToNonNull(
             getTreeType(((MemberSelectTree) tree.getMethodSelect()).getExpression(), state));

diff --git a/nullaway/src/test/java/com/uber/nullaway/NullAwayJSpecifyGenericsTests.java b/nullaway/src/test/java/com/uber/nullaway/NullAwayJSpecifyGenericsTests.java
@@ -1522,6 +1522,24 @@ public void testForStaticMethodCallAsAParam() {
         .doTest();
   }
 
+  @Test
+  public void testForDiamondOperatorReturnedAsAMethodCaller() {
+    makeHelper()
+        .addSourceLines(
+            "Test.java",
+            "package com.uber;",
+            "import org.jspecify.annotations.Nullable;",
+            "class Test {",
+            "  static class B<T>{",
+            "   String build(){return \"x\";}",
+            "  }",
+            "  static String testNegative() {",
+            "   return new B<>().build();",
+            "  }",
+            "}")
+        .doTest();
+  }
+
   private CompilationTestHelper makeHelper() {
     return makeTestHelperWithArgs(
         Arrays.asList(