Don't crash for CaseKind.RULE in SwitchDefault

Fixes #2705 PiperOrigin-RevId: 413868350
google · Dec 3, 2021 · b803e04 · b803e04
1 parent aa8f00b
commit b803e04
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Showing 2 changed files with 37 additions and 2 deletions.
diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/SwitchDefault.java b/core/src/main/java/com/google/errorprone/bugpatterns/SwitchDefault.java
@@ -28,6 +28,7 @@
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.util.Reachability;
 import com.sun.source.tree.CaseTree;
+import com.sun.source.tree.StatementTree;
 import com.sun.source.tree.SwitchTree;
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -52,17 +53,20 @@ public Description matchSwitch(SwitchTree tree, VisitorState state) {
     // Collect all case trees in the statement group containing the default
     List<CaseTree> defaultStatementGroup = new ArrayList<>();
     Iterator<? extends CaseTree> it = tree.getCases().iterator();
+    List<? extends StatementTree> caseTreeStatements = null;
     while (it.hasNext()) {
       CaseTree caseTree = it.next();
+      caseTreeStatements = caseTree.getStatements();
       defaultStatementGroup.add(caseTree);
       if (caseTree.getExpression() == null) {
-        while (it.hasNext() && caseTree.getStatements().isEmpty()) {
+        while (it.hasNext() && caseTreeStatements.isEmpty()) {
           caseTree = it.next();
+          caseTreeStatements = caseTree.getStatements();
           defaultStatementGroup.add(caseTree);
         }
         break;
       }
-      if (!caseTree.getStatements().isEmpty()) {
+      if (caseTreeStatements != null && !caseTreeStatements.isEmpty()) {
         defaultStatementGroup.clear();
       }
     }

diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/SwitchDefaultTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/SwitchDefaultTest.java
@@ -16,14 +16,22 @@
 
 package com.google.errorprone.bugpatterns;
 
+import static org.junit.Assume.assumeTrue;
+
 import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.CompilationTestHelper;
+import com.google.errorprone.util.RuntimeVersion;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
 /** {@link SwitchDefault}Test */
 @RunWith(JUnit4.class)
 public class SwitchDefaultTest {
+
+  private final CompilationTestHelper compilationHelper =
+      CompilationTestHelper.newInstance(SwitchDefault.class, getClass());
+
   private final BugCheckerRefactoringTestHelper testHelper =
       BugCheckerRefactoringTestHelper.newInstance(SwitchDefault.class, getClass());
 
@@ -224,4 +232,27 @@ public void refactoring_outOfOrder() {
             "}")
         .doTest();
   }
+
+  @Test
+  public void newNotation_validDefault() {
+    assumeTrue(RuntimeVersion.isAtLeast14());
+    compilationHelper
+        .addSourceLines(
+            "Test.java",
+            "class Test {",
+            "  public static void nothing1() { }",
+            "  public static void nothing2() { }",
+            "  public static void nothing3() { }",
+            "  public static void switchDefaultCrash(int i)",
+            "  {",
+            "        switch(i) {",
+            "            case 0 -> nothing1();",
+            "            case 1 -> nothing2();",
+            "            default -> nothing3();",
+            "        }",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
 }