Update TreeDiffer to scan resource variables

cushon · Compile-Testing Team · commit cb6486c955c4 · 2021-04-28T15:43:19.000-07:00
RELNOTES=Fix false negative when comparing source files that differ only in try-with-resources specifications.
PiperOrigin-RevId: 371001119
diff --git a/src/main/java/com/google/testing/compile/TreeDiffer.java b/src/main/java/com/google/testing/compile/TreeDiffer.java
@@ -831,6 +831,7 @@ public Void visitTry(TryTree expected, Tree actual) {
         return null;
       }
 
+      parallelScan(expected.getResources(), other.get().getResources());
       scan(expected.getBlock(), other.get().getBlock());
       parallelScan(expected.getCatches(), other.get().getCatches());
       scan(expected.getFinallyBlock(), other.get().getFinallyBlock());
diff --git a/src/test/java/com/google/testing/compile/TreeDifferTest.java b/src/test/java/com/google/testing/compile/TreeDifferTest.java
@@ -155,6 +155,22 @@ public class TreeDifferTest {
           "  };",
           "}");
 
+  private static final CompilationUnitTree TRY_WITH_RESOURCES_1 =
+      MoreTrees.parseLinesToTree("package test;",
+          "final class TestClass {",
+          "  void f() {",
+          "    try (Resource1 r = new Resource1()) {}",
+          "  }",
+          "}");
+
+  private static final CompilationUnitTree TRY_WITH_RESOURCES_2 =
+      MoreTrees.parseLinesToTree("package test;",
+          "final class TestClass {",
+          "  void f() {",
+          "    try (Resource2 r = new Resource2()) {}",
+          "  }",
+          "}");
+
   @Test
   public void scan_differingCompilationUnits() {
     TreeDifference diff = TreeDiffer.diffCompilationUnits(EXPECTED_TREE, ACTUAL_TREE);
@@ -284,6 +300,20 @@ public void scan_testLambdaVersusAnonymousClass() {
     assertThat(diff.isEmpty()).isFalse();
   }
 
+  @Test
+  public void scan_testTryWithResources() {
+    TreeDifference diff =
+        TreeDiffer.diffCompilationUnits(TRY_WITH_RESOURCES_1, TRY_WITH_RESOURCES_1);
+    assertThat(diff.isEmpty()).isTrue();
+  }
+
+  @Test
+  public void scan_testTryWithResourcesDifferent() {
+    TreeDifference diff =
+        TreeDiffer.diffCompilationUnits(TRY_WITH_RESOURCES_1, TRY_WITH_RESOURCES_2);
+    assertThat(diff.isEmpty()).isFalse();
+  }
+
   @Test
   public void matchCompilationUnits() {
     ParseResult actual =

Original file line number	Diff line number	Diff line change
`@@ -831,6 +831,7 @@ public Void visitTry(TryTree expected, Tree actual) {`
`831`	`831`	`return null;`
`832`	`832`	`}`
`833`	`833`
	`834`	`+ parallelScan(expected.getResources(), other.get().getResources());`
`834`	`835`	`scan(expected.getBlock(), other.get().getBlock());`
`835`	`836`	`parallelScan(expected.getCatches(), other.get().getCatches());`
`836`	`837`	`scan(expected.getFinallyBlock(), other.get().getFinallyBlock());`