Prefer Guava version of VisibleForTesting annotation

baseline-error-prone/build.gradle

@@ -37,6 +37,8 @@ dependencies {
     testRuntimeOnly 'com.fasterxml.jackson.module:jackson-module-afterburner'
     // for ForbidJavax
     testRuntimeOnly 'com.palantir.conjure.java.runtime:conjure-java-annotations'
+    // for PreferCommonAnnotations
+    testRuntimeOnly 'org.jetbrains:annotations'
 
     annotationProcessor 'com.google.auto.service:auto-service'
     compileOnly 'org.immutables:value::annotations'

baseline-error-prone/src/main/java/com/palantir/baseline/errorprone/PreferCommonAnnotations.java

@@ -0,0 +1,66 @@
+/*
+ * (c) Copyright 2023 Palantir Technologies 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.palantir.baseline.errorprone;
+
+import com.google.auto.service.AutoService;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.BugPattern.SeverityLevel;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.ImportTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.ImportTree;
+import com.sun.tools.javac.code.Type;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * Checker that recommends using the common version of an annotation.
+ *
+ * Examples:
+ * - Guava's version of {@code @VisibleForTesting} over other copies.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(
+        summary = "Prefer the common version of annotations over other copies.",
+        severity = SeverityLevel.SUGGESTION)
+public final class PreferCommonAnnotations extends BugChecker implements ImportTreeMatcher {
+
+    /** ClassName -> preferred import. */
+    private static final Map<String, String> PREFERRED_IMPORTS =
+            Map.of("VisibleForTesting", "com.google.common.annotations.VisibleForTesting");
+
+    @Override
+    public Description matchImport(ImportTree tree, VisitorState state) {
+        Type importType = ASTHelpers.getType(tree.getQualifiedIdentifier());
+        for (String affectedClassName : PREFERRED_IMPORTS.keySet()) {
+            String preferredType = PREFERRED_IMPORTS.get(affectedClassName);
+            if (importType != null
+                    && importType.toString().endsWith(affectedClassName)
+                    && !Objects.equals(importType.toString(), preferredType)) {
+                SuggestedFix fix = SuggestedFix.builder()
+                        .removeImport(importType.toString())
+                        .addImport(preferredType)
+                        .build();
+                return describeMatch(tree, fix);
+            }
+        }
+        return Description.NO_MATCH;
+    }
+}

baseline-error-prone/src/test/java/com/palantir/baseline/errorprone/PreferCommonAnnotationsTest.java

@@ -0,0 +1,100 @@
+/*
+ * (c) Copyright 2023 Palantir Technologies 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.palantir.baseline.errorprone;
+
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+public final class PreferCommonAnnotationsTest {
+    @Test
+    public void desired_import_remains_unchanged() {
+        fix().addInputLines(
+                        "Client.java",
+                        "package com.google.frobber;",
+                        "import com.google.common.annotations.VisibleForTesting;",
+                        "public final class Client {",
+                        "  @VisibleForTesting",
+                        "  public int getValue() {",
+                        "    return 42;",
+                        "  }",
+                        "}")
+                .expectUnchanged()
+                .doTest();
+    }
+
+    @Test
+    public void other_import_is_replaced() {
+        fix().addInputLines(
+                        "Client.java",
+                        "package com.google.frobber;",
+                        "import org.jetbrains.annotations.VisibleForTesting;",
+                        "public final class Client {",
+                        "  @VisibleForTesting",
+                        "  public int getValue() {",
+                        "    return 42;",
+                        "  }",
+                        "}")
+                .addOutputLines(
+                        "Client.java",
+                        "package com.google.frobber;",
+                        "import com.google.common.annotations.VisibleForTesting;",
+                        "public final class Client {",
+                        "  @VisibleForTesting",
+                        "  public int getValue() {",
+                        "    return 42;",
+                        "  }",
+                        "}")
+                .doTest();
+    }
+
+    @Test
+    public void fully_qualified_annotations_are_not_currently_rewritten() {
+        CompilationTestHelper.newInstance(PreferCommonAnnotations.class, getClass())
+                .addSourceLines(
+                        "Client.java",
+                        "package com.google.frobber;",
+                        "public final class Client {",
+                        // NOTE: fully-qualified annotations are not currently re-written
+                        "  @org.jetbrains.annotations.VisibleForTesting",
+                        "  public int getValue() {",
+                        "    return 42;",
+                        "  }",
+                        "}")
+                .doTest();
+    }
+
+    @Test
+    public void wildcard_import_annotations_are_not_currently_rewritten() {
+        CompilationTestHelper.newInstance(PreferCommonAnnotations.class, getClass())
+                .addSourceLines(
+                        "Client.java",
+                        "package com.google.frobber;",
+                        "import org.jetbrains.annotations.*;",
+                        "public final class Client {",
+                        // NOTE: wildcard-imported annotations are not currently re-written
+                        "  @VisibleForTesting",
+                        "  public int getValue() {",
+                        "    return 42;",
+                        "  }",
+                        "}")
+                .doTest();
+    }
+
+    private RefactoringValidator fix() {
+        return RefactoringValidator.of(PreferCommonAnnotations.class, getClass());
+    }
+}

changelog/@unreleased/pr-2505.v2.yml

@@ -0,0 +1,5 @@
+type: feature
+feature:
+  description: Prefer common versions of annotations over other copies
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/2505