Merge pull request #90 from HubSpot/tk/class-init-deadlock-method-refs-fork

Allow lambdas and method references referencing subclasses

Author: tkindy

core/src/main/java/com/google/errorprone/bugpatterns/ClassInitializationDeadlock.java

@@ -38,6 +38,8 @@
 import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.IdentifierTree;
+import com.sun.source.tree.LambdaExpressionTree;
+import com.sun.source.tree.MemberReferenceTree;
 import com.sun.source.tree.MemberSelectTree;
 import com.sun.source.tree.MethodTree;
 import com.sun.source.tree.Tree;
@@ -112,6 +114,16 @@ public Void visitMethod(MethodTree node, Void unused) {
         return null;
       }
 
+      @Override
+      public Void visitMemberReference(MemberReferenceTree node, Void unused) {
+        return null;
+      }
+
+      @Override
+      public Void visitLambdaExpression(LambdaExpressionTree node, Void unused) {
+        return null;
+      }
+
       @Override
       public Void visitMemberSelect(MemberSelectTree tree, Void unused) {
         if (ASTHelpers.constValue(tree) != null) {

core/src/test/java/com/google/errorprone/bugpatterns/ClassInitializationDeadlockTest.java

@@ -18,6 +18,7 @@
 
 import com.google.auto.value.processor.AutoValueProcessor;
 import com.google.errorprone.CompilationTestHelper;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -309,4 +310,63 @@ public void nonNestedSubclass() {
             "class B extends A {}")
         .doTest();
   }
+
+  @Test
+  public void simpleSubclassMethodReference() {
+    testHelper
+        .addSourceLines(
+            "Foo.java",
+            "import java.util.function.Supplier;",
+            "class A {",
+            "  static Supplier<B> supplier = B::new;",
+            "}",
+            "class B extends A {}")
+        .doTest();
+  }
+
+  @Test
+  public void compoundSubclassMethodReference() {
+    testHelper
+        .addSourceLines(
+            "Foo.java",
+            "import java.util.Comparator;",
+            "class A {",
+            "  static Comparator<B> comparator = Comparator.comparing(B::value);",
+            "}",
+            "class B extends A {",
+            "  int value;",
+            "  int value() {",
+            "    return value;",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  public void lambda() {
+    testHelper
+        .addSourceLines(
+            "Foo.java",
+            "import java.util.function.Supplier;",
+            "class A {",
+            "  static Supplier<B> supplier = () -> new B();",
+            "}",
+            "class B extends A {}")
+        .doTest();
+  }
+
+  @Test
+  public void subclassStaticMethod() {
+    testHelper
+        .addSourceLines(
+            "Foo.java",
+            "class A {",
+            "  // BUG: Diagnostic contains:",
+            "  static int value = B.value(); ",
+            "}",
+            "class B extends A {",
+            "  static int value() { return 0; }",
+            "}")
+        .doTest();
+  }
 }