Feature: Add consistent logging errorprone rule

README.md

@@ -202,6 +202,7 @@ Safe Logging can be found at [github.com/palantir/safe-logging](https://github.c
 - `IncubatingMethod`: Prevents calling Conjure incubating APIs unless you explicitly opt-out of the check on a per-use or per-project basis.
 - `CompileTimeConstantViolatesLiskovSubstitution`: Requires consistent application of the `@CompileTimeConstant` annotation to resolve inconsistent validation based on the reference type on which the met is invoked.
 - `ClassInitializationDeadlock`: Detect type structures which can cause deadlocks initializing classes.
+- `ConsistentLoggerName`: Ensure Loggers are named consistently.
 
 ### Programmatic Application
 

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

@@ -0,0 +1,60 @@
+/*
+ * (c) Copyright 2020 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.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+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.matchers.method.MethodMatchers;
+import com.sun.source.tree.VariableTree;
+
+@AutoService(BugChecker.class)
+@BugPattern(
+        name = "ConsistentLoggerName",
+        link = "https://github.com/palantir/gradle-baseline#baseline-error-prone-checks",
+        linkType = BugPattern.LinkType.CUSTOM,
+        providesFix = BugPattern.ProvidesFix.REQUIRES_HUMAN_ATTENTION,
+        severity = BugPattern.SeverityLevel.WARNING,
+        summary = "Loggers created using getLogger(Class<?>) must be named 'log'.")
+public final class ConsistentLoggerName extends BugChecker implements BugChecker.VariableTreeMatcher {
+
+    private static final Matcher<VariableTree> matcher = Matchers.allOf(
+            Matchers.isField(),
+            Matchers.isStatic(),
+            MoreMatchers.isFinal(),
+            Matchers.isSubtypeOf("org.slf4j.Logger"),
+            Matchers.variableInitializer(MethodMatchers.staticMethod()
+                    .onClass("org.slf4j.LoggerFactory")
+                    .named("getLogger")
+                    // Only match the 'class' constructor
+                    .withParameters(Class.class.getName())));
+
+    @Override
+    public Description matchVariable(VariableTree tree, VisitorState state) {
+        if (matcher.matches(tree, state) && !tree.getName().contentEquals("log")) {
+            return buildDescription(tree)
+                    .addFix(SuggestedFixes.renameVariable(tree, "log", state))
+                    .build();
+        }
+        return Description.NO_MATCH;
+    }
+}

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

@@ -16,6 +16,9 @@
 
 package com.palantir.baseline.errorprone;
 
+import static com.google.errorprone.util.ASTHelpers.getSymbol;
+import static com.sun.tools.javac.code.Flags.FINAL;
+
 import com.google.errorprone.VisitorState;
 import com.google.errorprone.matchers.Matcher;
 import com.google.errorprone.matchers.Matchers;
@@ -118,5 +121,12 @@ static Matcher<MethodTree> hasSignature(String signature) {
         };
     }
 
+    public static <T extends Tree> Matcher<T> isFinal() {
+        return (tree, state) -> {
+            Symbol sym = getSymbol(tree);
+            return sym != null && (sym.flags_field & FINAL) != 0;
+        };
+    }
+
     private MoreMatchers() {}
 }

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

@@ -0,0 +1,100 @@
+/*
+ * (c) Copyright 2020 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 org.junit.jupiter.api.Test;
+
+class ConsistentLoggerNameTest {
+
+    @Test
+    void testFix() {
+        fix().addInputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private static final Logger LOG = LoggerFactory.getLogger(Test.class);",
+                        "}")
+                .addOutputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private static final Logger log = LoggerFactory.getLogger(Test.class);",
+                        "}")
+                .doTest();
+    }
+
+    @Test
+    void testFix_references() {
+        fix().addInputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private static final Logger LOG = LoggerFactory.getLogger(Test.class);",
+                        "    private void foo() {",
+                        "        LOG.error(\"error\");",
+                        "    }",
+                        "}")
+                .addOutputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private static final Logger log = LoggerFactory.getLogger(Test.class);",
+                        "    private void foo() {",
+                        "        log.error(\"error\");",
+                        "    }",
+                        "}")
+                .doTest();
+    }
+
+    @Test
+    void ignores_local_variables() {
+        fix().addInputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private Logger LOG = LoggerFactory.getLogger(Test.class);",
+                        "}")
+                .addOutputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private Logger LOG = LoggerFactory.getLogger(Test.class);",
+                        "}")
+                .doTest();
+    }
+
+    @Test
+    void ignores_non_final_methods() {
+        fix().addInputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private static Logger LOG = LoggerFactory.getLogger(Test.class);",
+                        "}")
+                .addOutputLines(
+                        "Test.java",
+                        "import org.slf4j.*;",
+                        "class Test {",
+                        "    private static Logger LOG = LoggerFactory.getLogger(Test.class);",
+                        "}")
+                .doTest();
+    }
+
+    private RefactoringValidator fix() {
+        return RefactoringValidator.of(new ConsistentLoggerName(), getClass());
+    }
+}

changelog/@unreleased/pr-1644.v2.yml

@@ -0,0 +1,5 @@
+type: feature
+feature:
+  description: Add consistent logging errorprone rule
+  links:
+  - https://github.com/palantir/gradle-baseline/pull/1644

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

@@ -34,6 +34,7 @@ public class BaselineErrorProneExtension {
             // "CatchSpecificity",
             "CollectionStreamForEach",
             "CompileTimeConstantViolatesLiskovSubstitution",
+            "ConsistentLoggerName",
             "DeprecatedGuavaObjects",
             "ExecutorSubmitRunnableFutureIgnored",
             "ExtendsErrorOrThrowable",