Add BugCheckerAutoService

README.md

@@ -207,7 +207,8 @@ Safe Logging can be found at [github.com/palantir/safe-logging](https://github.c
 - `PreferImmutableStreamExCollections`: It's common to use toMap/toSet/toList() as the terminal operation on a stream, but would be extremely surprising to rely on the mutability of these collections. Prefer `toImmutableMap`, `toImmutableSet` and `toImmutableList`. (If the performance overhead of a stream is already acceptable, then the `UnmodifiableFoo` wrapper is likely tolerable).
 - `DangerousIdentityKey`: Key type does not override equals() and hashCode, so comparisons will be done on reference equality only.
 - `ConsistentOverrides`: Ensure values are bound to the correct variables when overriding methods
-- `FilterOutputStreamSlowMultibyteWrite`:Subclasses of FilterOutputStream should provide a more efficient implementation of `write(byte[], int, int)` to avoid slow writes.
+- `FilterOutputStreamSlowMultibyteWrite`: Subclasses of FilterOutputStream should provide a more efficient implementation of `write(byte[], int, int)` to avoid slow writes.
+- `BugCheckerAutoService`: Concrete BugChecker implementations should be annotated `@AutoService(BugChecker.class)` for auto registration with error-prone.
 
 ### Programmatic Application
 

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

@@ -0,0 +1,83 @@
+/*
+ * (c) Copyright 2022 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.BugPattern.StandardTags;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.fixes.SuggestedFixes;
+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.AnnotationTree;
+import com.sun.source.tree.ClassTree;
+import com.sun.tools.javac.code.Symbol.TypeSymbol;
+import java.util.List;
+import javax.lang.model.element.ElementKind;
+
+@AutoService(BugChecker.class)
+@BugPattern(
+        name = "BugCheckerAutoService",
+        link = "https://github.com/palantir/gradle-baseline#baseline-error-prone-checks",
+        linkType = BugPattern.LinkType.CUSTOM,
+        summary = "Concrete BugChecker implementations should be annotated "
+                + "`@AutoService(BugChecker.class)` for auto registration with error-prone.",
+        severity = SeverityLevel.ERROR,
+        tags = StandardTags.LIKELY_ERROR)
+public final class BugCheckerAutoService extends BugChecker implements ClassTreeMatcher {
+
+    private static final String AUTO_SERVICE = "com.google.auto.service.AutoService";
+    private static final Matcher<ClassTree> isBugChecker =
+            Matchers.allOf(Matchers.isSubtypeOf(BugChecker.class), Matchers.hasAnnotation(BugPattern.class));
+
+    private static final Matcher<AnnotationTree> autoServiceBugChecker = Matchers.allOf(
+            Matchers.isType(AUTO_SERVICE),
+            Matchers.hasArgumentWithValue("value", Matchers.classLiteral(Matchers.isSameType(BugChecker.class))));
+
+    @Override
+    public Description matchClass(ClassTree classTree, VisitorState state) {
+        if (!isBugChecker.matches(classTree, state)) {
+            return Description.NO_MATCH;
+        }
+
+        TypeSymbol thisClassSymbol = ASTHelpers.getSymbol(classTree);
+        if (thisClassSymbol.getKind() != ElementKind.CLASS) {
+            return Description.NO_MATCH;
+        }
+
+        List<? extends AnnotationTree> annotations = ASTHelpers.getAnnotations(classTree);
+        boolean hasAutoServiceBugChecker =
+                annotations.stream().anyMatch(annotationTree -> autoServiceBugChecker.matches(annotationTree, state));
+        if (hasAutoServiceBugChecker) {
+            return Description.NO_MATCH;
+        }
+
+        SuggestedFix.Builder fix = SuggestedFix.builder();
+        String autoService = SuggestedFixes.qualifyType(state, fix, AUTO_SERVICE);
+        String bugChecker = SuggestedFixes.qualifyType(state, fix, BugChecker.class.getName());
+        return buildDescription(classTree)
+                .addFix(fix.prefixWith(classTree, "@" + autoService + "(" + bugChecker + ".class)\n")
+                        .build())
+                .build();
+    }
+}

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

@@ -0,0 +1,84 @@
+/*
+ * (c) Copyright 2022 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;
+
+class BugCheckerAutoServiceTest {
+
+    private CompilationTestHelper compilationHelper() {
+        return CompilationTestHelper.newInstance(BugCheckerAutoService.class, getClass());
+    }
+
+    private RefactoringValidator fix() {
+        return RefactoringValidator.of(BugCheckerAutoService.class, getClass());
+    }
+
+    @Test
+    public void doingItRight() {
+        compilationHelper()
+                .addSourceLines(
+                        "TestChecker.java",
+                        "import com.google.auto.service.AutoService;",
+                        "import com.google.errorprone.BugPattern;",
+                        "import com.google.errorprone.bugpatterns.BugChecker;",
+                        "import com.google.errorprone.BugPattern.SeverityLevel;",
+                        "@AutoService(BugChecker.class)",
+                        "@BugPattern(name=\"Test\", summary=\"a\", severity=SeverityLevel.ERROR)",
+                        "public class TestChecker extends BugChecker {",
+                        "}")
+                .doTest();
+    }
+
+    @Test
+    public void nonCheckerAutoService() {
+        compilationHelper()
+                .addSourceLines(
+                        "Test.java",
+                        "import com.google.auto.service.AutoService;",
+                        "@AutoService(Runnable.class)",
+                        "public class Test implements Runnable {",
+                        "  public void run() {}",
+                        "}")
+                .doTest();
+    }
+
+    @Test
+    public void fixBugChecker() {
+        fix().addInputLines(
+                        "TestChecker.java",
+                        "import com.google.auto.service.AutoService;",
+                        "import com.google.errorprone.BugPattern;",
+                        "import com.google.errorprone.bugpatterns.BugChecker;",
+                        "import com.google.errorprone.BugPattern.SeverityLevel;",
+                        "@BugPattern(name=\"Test\", summary=\"a\", severity=SeverityLevel.ERROR)",
+                        "public class TestChecker extends BugChecker {",
+                        "}")
+                .addOutputLines(
+                        "TestChecker.java",
+                        "import com.google.auto.service.AutoService;",
+                        "import com.google.errorprone.BugPattern;",
+                        "import com.google.errorprone.bugpatterns.BugChecker;",
+                        "import com.google.errorprone.BugPattern.SeverityLevel;",
+                        "@AutoService(BugChecker.class)",
+                        "@BugPattern(name=\"Test\", summary=\"a\", severity=SeverityLevel.ERROR)",
+                        "public class TestChecker extends BugChecker {",
+                        "}")
+                .doTest();
+    }
+}

changelog/@unreleased/pr-2028.v2.yml

@@ -0,0 +1,9 @@
+type: improvement
+improvement:
+  description: |-
+    Add BugCheckerAutoService
+
+    Concrete BugChecker implementations should be annotated
+    `@AutoService(BugChecker.class)` for auto registration with error-prone.
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/2028

gradle-baseline-java/src/main/groovy/com/palantir/baseline/extensions/BaselineErrorProneExtension.java

@@ -30,6 +30,7 @@ public class BaselineErrorProneExtension {
             // Baseline checks
             "AssertNoArgs",
             "AvoidNewHashMapInt",
+            "BugCheckerAutoService",
             "CatchBlockLogException",
             // TODO(ckozak): re-enable pending scala check
             // "CatchSpecificity",