Add a test for ArraysAsListPrimitiveArray

and then fix the check so the test passes.

MOE_MIGRATED_REVID=127252244

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

@@ -19,8 +19,12 @@
 import static com.google.errorprone.BugPattern.Category.JDK;
 import static com.google.errorprone.BugPattern.MaturityLevel.EXPERIMENTAL;
 import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
+import static com.google.errorprone.matchers.Description.NO_MATCH;
+import static com.google.errorprone.matchers.Matchers.allOf;
 import static com.google.errorprone.matchers.Matchers.staticMethod;
 
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Iterables;
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
@@ -29,38 +33,39 @@
 import com.google.errorprone.matchers.Description;
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.matchers.Matchers;
-
+import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.ExpressionTree;
 import com.sun.source.tree.MethodInvocationTree;
 import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.code.Type.ArrayType;
-import com.sun.tools.javac.tree.JCTree;
-
-import java.util.Collections;
 import java.util.EnumMap;
 import java.util.Map;
-
 import javax.lang.model.type.TypeKind;
 
-@BugPattern(name = "ArraysAsListPrimitiveArray",
-    summary =
-        "Arrays.asList does not autobox primitive arrays, as one might expect.",
-    explanation =
-        "Arrays.asList does not autobox primitive arrays, as one might expect. " +
-        "If you intended to autobox the primitive array, use an asList method " +
-        "from Guava that does autobox.  If you intended to create a singleton " +
-        "list containing the primitive array, use Collections.singletonList to " +
-        "make your intent clearer.",
-    category = JDK, severity = ERROR, maturity = EXPERIMENTAL)
+@BugPattern(
+  name = "ArraysAsListPrimitiveArray",
+  summary = "Arrays.asList does not autobox primitive arrays, as one might expect.",
+  explanation =
+      "Arrays.asList does not autobox primitive arrays, as one might expect. "
+          + "If you intended to autobox the primitive array, use an asList method "
+          + "from Guava that does autobox.  If you intended to create a singleton "
+          + "list containing the primitive array, use Collections.singletonList to "
+          + "make your intent clearer.",
+  category = JDK,
+  severity = ERROR,
+  maturity = EXPERIMENTAL
+)
 public class ArraysAsListPrimitiveArray extends BugChecker implements MethodInvocationTreeMatcher {
-  private static final Matcher<MethodInvocationTree> ARRAYS_AS_LIST_SINGLE_ARRAY = Matchers.allOf(
-      staticMethod().onClass("java.util.Arrays").named("asList"),
-      Matchers.argumentCount(1),
-      Matchers.argument(1, Matchers.<ExpressionTree>isArrayType()));
 
-  private static final Map<TypeKind, String> GUAVA_UTILS;
+  private static final Matcher<MethodInvocationTree> ARRAYS_AS_LIST_SINGLE_ARRAY =
+      allOf(
+          staticMethod().onClass("java.util.Arrays").named("asList"),
+          Matchers.argumentCount(1),
+          Matchers.argument(0, Matchers.<ExpressionTree>isArrayType()));
 
-  static {
+  private static final ImmutableMap<TypeKind, String> GUAVA_UTILS = getGuavaUtils();
+
+  static ImmutableMap<TypeKind, String> getGuavaUtils() {
     Map<TypeKind, String> guavaUtils = new EnumMap<>(TypeKind.class);
     guavaUtils.put(TypeKind.BOOLEAN, "Booleans");
     guavaUtils.put(TypeKind.BYTE, "Bytes");
@@ -70,25 +75,28 @@ public class ArraysAsListPrimitiveArray extends BugChecker implements MethodInvo
     guavaUtils.put(TypeKind.CHAR, "Chars");
     guavaUtils.put(TypeKind.FLOAT, "Floats");
     guavaUtils.put(TypeKind.DOUBLE, "Doubles");
-    GUAVA_UTILS = Collections.unmodifiableMap(guavaUtils);
+    return ImmutableMap.copyOf(guavaUtils);
   }
 
   @Override
   public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
-    if (ARRAYS_AS_LIST_SINGLE_ARRAY.matches(tree, state)) {
-      JCTree array = (JCTree) tree.getArguments().get(0);
-      Type componentType = ((ArrayType) array.type).getComponentType();
-      String guavaUtils = GUAVA_UTILS.get(componentType.getKind());
-      if (guavaUtils != null) {
-        Fix fix = SuggestedFix.builder()
+    if (!ARRAYS_AS_LIST_SINGLE_ARRAY.matches(tree, state)) {
+      return NO_MATCH;
+    }
+    ExpressionTree array = Iterables.getOnlyElement(tree.getArguments());
+    Type componentType = ((ArrayType) ASTHelpers.getType(array)).getComponentType();
+    if (!componentType.isPrimitive()) {
+      return NO_MATCH;
+    }
+    String guavaUtils = GUAVA_UTILS.get(componentType.getKind());
+    if (guavaUtils == null) {
+      return NO_MATCH;
+    }
+    Fix fix =
+        SuggestedFix.builder()
             .addImport("com.google.common.primitives." + guavaUtils)
             .replace(tree.getMethodSelect(), guavaUtils + ".asList")
             .build();
-        return describeMatch(tree, fix);
-      }
-    }
-
-    return Description.NO_MATCH;
+    return describeMatch(tree, fix);
   }
 }
-

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

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.errorprone.bugpatterns;
+
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** {@link ArraysAsListPrimitiveArray}Test */
+@RunWith(JUnit4.class)
+public class ArraysAsListPrimitiveArrayTest {
+
+  private final CompilationTestHelper compilationHelper =
+      CompilationTestHelper.newInstance(ArraysAsListPrimitiveArray.class, getClass());
+
+  @Test
+  public void positive() throws Exception {
+    compilationHelper
+        .addSourceLines(
+            "Test.java",
+            "import java.util.Arrays;",
+            "class Test {",
+            "void f() {",
+            "  // BUG: Diagnostic contains: Booleans.asList(new boolean[0]);",
+            "  Arrays.asList(new boolean[0]);",
+            "  // BUG: Diagnostic contains: Bytes.asList(new byte[0]);",
+            "  Arrays.asList(new byte[0]);",
+            "  // BUG: Diagnostic contains: Shorts.asList(new short[0]);",
+            "  Arrays.asList(new short[0]);",
+            "  // BUG: Diagnostic contains: Chars.asList(new char[0]);",
+            "  Arrays.asList(new char[0]);",
+            "  // BUG: Diagnostic contains: Ints.asList(new int[0]);",
+            "  Arrays.asList(new int[0]);",
+            "  // BUG: Diagnostic contains: Longs.asList(new long[0]);",
+            "  Arrays.asList(new long[0]);",
+            "  // BUG: Diagnostic contains: Doubles.asList(new double[0]);",
+            "  Arrays.asList(new double[0]);",
+            "  // BUG: Diagnostic contains: Floats.asList(new float[0]);",
+            "  Arrays.asList(new float[0]);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  public void negative() throws Exception {
+    compilationHelper
+        .addSourceLines(
+            "Test.java",
+            "import java.util.Arrays;",
+            "class Test {",
+            "void f() {",
+            "  Arrays.asList(new Object());",
+            "  Arrays.asList(new Object[0]);",
+            "  Arrays.asList(new Integer[0]);",
+            "  }",
+            "}")
+        .doTest();
+  }
+}