Fix a crash in NestedInstanceOfConditions.

Fixes external #4349 PiperOrigin-RevId: 633572373
google · May 14, 2024 · 52988bc · 52988bc
1 parent 2a06dd3
commit 52988bc
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diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/NestedInstanceOfConditions.java b/core/src/main/java/com/google/errorprone/bugpatterns/NestedInstanceOfConditions.java
@@ -120,6 +120,11 @@ public boolean matches(Tree tree, VisitorState state) {
 
           Types types = state.getTypes();
 
+          // Pattern matching instanceofs can have null type.
+          if (instanceOfTree.getType() == null) {
+            return false;
+          }
+
           boolean isCastable =
               types.isCastable(
                   types.erasure(ASTHelpers.getType(instanceOfTree.getType())),

diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/NestedInstanceOfConditionsTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/NestedInstanceOfConditionsTest.java
@@ -16,7 +16,10 @@
 
 package com.google.errorprone.bugpatterns;
 
+import static com.google.common.truth.TruthJUnit.assume;
+
 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;
@@ -40,4 +43,21 @@ public void positiveCase() {
   public void negativeCase() {
     compilationHelper.addSourceFile("NestedInstanceOfConditionsNegativeCases.java").doTest();
   }
+
+  @Test
+  public void patternMatchingInstanceof() {
+    assume().that(RuntimeVersion.isAtLeast21()).isTrue();
+    compilationHelper
+        .addSourceLines(
+            "Test.java",
+            "public class Test {",
+            "  record Struct(Object a) {}",
+            "  public void test(Object x, Object y) {",
+            "    if (x instanceof Struct(Integer a1)) {",
+            "      if (y instanceof Struct(Integer a2)) {}",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
 }