Skylint: add categories for issues.

Having a short canonical name for each kind of finding (the category) makes it easier to document all the lints and for users to find the documentation for each lint.

RELNOTES: none
PiperOrigin-RevId: 171972645

19 files changed, 239 insertions, 113 deletions

diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/BadOperationChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/BadOperationChecker.java
index 8b08bdff65..7be8e8199d 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/BadOperationChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/BadOperationChecker.java
@@ -26,6 +26,8 @@ import java.util.List;
 
 /** Checks for operations that are deprecated */
 public class BadOperationChecker extends SyntaxTreeVisitor {
+  private static final String DEPRECATED_PLUS_DICT_CATEGORY = "deprecated-plus-dict";
+
   private final List<Issue> issues = new ArrayList<>();
 
   private BadOperationChecker() {}
@@ -45,7 +47,8 @@ public class BadOperationChecker extends SyntaxTreeVisitor {
           || node.getRhs() instanceof DictionaryLiteral
           || node.getRhs() instanceof DictComprehension) {
         issues.add(
-            new Issue(
+            Issue.create(
+                DEPRECATED_PLUS_DICT_CATEGORY,
                 "'+' operator is deprecated and should not be used on dictionaries",
                 node.getLocation()));
       }
@@ -58,7 +61,8 @@ public class BadOperationChecker extends SyntaxTreeVisitor {
     if (node.getExpression() instanceof DictionaryLiteral
         || node.getExpression() instanceof DictComprehension) {
       issues.add(
-          new Issue(
+          Issue.create(
+              DEPRECATED_PLUS_DICT_CATEGORY,
               "'+' operator is deprecated and should not be used on dictionaries",
               node.getLocation()));
     }
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java
index c32e0ac9c6..63af0dff75 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/ControlFlowChecker.java
@@ -45,6 +45,9 @@ import javax.annotation.Nullable;
  */
 // TODO(skylark-team): Check for unreachable statements
 public class ControlFlowChecker extends SyntaxTreeVisitor {
+  private static final String MISSING_RETURN_VALUE_CATEGORY = "missing-return-value";
+  public static final String UNREACHABLE_STATEMENT_CATEGORY = "unreachable-statement";
+
   private final List<Issue> issues = new ArrayList<>();
 
   /**
@@ -75,7 +78,9 @@ public class ControlFlowChecker extends SyntaxTreeVisitor {
     boolean alreadyReported = false;
     for (Statement stmt : statements) {
       if (!cfi.reachable && !alreadyReported) {
-        issues.add(new Issue("unreachable statement", stmt.getLocation()));
+        issues.add(
+            Issue.create(
+                UNREACHABLE_STATEMENT_CATEGORY, "unreachable statement", stmt.getLocation()));
         alreadyReported = true;
       }
       visit(stmt);
@@ -156,12 +161,14 @@ public class ControlFlowChecker extends SyntaxTreeVisitor {
     super.visit(node);
     if (cfi.hasReturnWithValue && (!cfi.returnsAlwaysExplicitly || cfi.hasReturnWithoutValue)) {
       issues.add(
-          new Issue(
+          Issue.create(
+              MISSING_RETURN_VALUE_CATEGORY,
               "some but not all execution paths of '" + node.getIdentifier() + "' return a value",
               node.getLocation()));
       for (Wrapper<ReturnStatement> returnWrapper : cfi.returnStatementsWithoutValue) {
         issues.add(
-            new Issue(
+            Issue.create(
+                MISSING_RETURN_VALUE_CATEGORY,
                 "return value missing (you can `return None` if this is desired)",
                 unwrapReturn(returnWrapper).getLocation()));
       }
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/DeprecationChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/DeprecationChecker.java
index 923f6360d6..23ce556efa 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/DeprecationChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/DeprecationChecker.java
@@ -30,6 +30,8 @@ import java.util.Map;
 
 /** Checks for usage of deprecated functions. */
 public class DeprecationChecker extends AstVisitorWithNameResolution {
+  private static final String DEPRECATED_SYMBOL_CATEGORY = "deprecated-symbol";
+
   private final List<Issue> issues = new ArrayList<>();
   /** Maps a global function name to its deprecation warning, if any. */
   private final Map<String, String> functionToDeprecationWarning = new HashMap<>();
@@ -83,7 +85,8 @@ public class DeprecationChecker extends AstVisitorWithNameResolution {
         && info.kind != Kind.LOCAL) {
       String deprecationMessage = functionToDeprecationWarning.get(info.name);
       issues.add(
-          new Issue(
+          Issue.create(
+              DEPRECATED_SYMBOL_CATEGORY,
               "usage of '" + info.name + "' is deprecated: " + deprecationMessage,
               ident.getLocation()));
     }
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java
index c19a68b58f..bc9edc37de 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/DocstringChecker.java
@@ -33,6 +33,10 @@ import java.util.List;
 
 /** Checks the existence of docstrings. */
 public class DocstringChecker extends SyntaxTreeVisitor {
+  private static final String MISSING_DOCSTRING_CATEGORY = "missing-docstring";
+  private static final String INCONSISTENT_DOCSTRING_CATEGORY = "inconsistent-docstring";
+  private static final String BAD_DOCSTRING_FORMAT_CATEGORY = "bad-docstring-format";
+
   private final List<Issue> issues = new ArrayList<>();
   private boolean containsReturnWithValue = false;
 
@@ -51,7 +55,7 @@ public class DocstringChecker extends SyntaxTreeVisitor {
       // This location is invalid if the file is empty but this edge case is not worth the trouble.
       Location end = new Location(2, 1);
       LocationRange range = new LocationRange(start, end);
-      issues.add(new Issue("file has no module docstring", range));
+      issues.add(new Issue(MISSING_DOCSTRING_CATEGORY, "file has no module docstring", range));
     } else {
       List<DocstringParseError> errors = new ArrayList<>();
       DocstringUtils.parseDocstring(moduleDocstring, errors);
@@ -76,7 +80,8 @@ public class DocstringChecker extends SyntaxTreeVisitor {
     StringLiteral functionDocstring = extractDocstring(node.getStatements());
     if (functionDocstring == null && !node.getIdentifier().getName().startsWith("_")) {
       issues.add(
-          new Issue(
+          Issue.create(
+              MISSING_DOCSTRING_CATEGORY,
               "function '" + node.getIdentifier().getName() + "' has no docstring",
               node.getLocation()));
     }
@@ -102,7 +107,8 @@ public class DocstringChecker extends SyntaxTreeVisitor {
       List<Issue> issues) {
     if (functionReturnsWithValue && docstring.returns.isEmpty()) {
       issues.add(
-          new Issue(
+          Issue.create(
+              INCONSISTENT_DOCSTRING_CATEGORY,
               "incomplete docstring: the return value is not documented",
               docstringLiteral.getLocation()));
     }
@@ -133,7 +139,8 @@ public class DocstringChecker extends SyntaxTreeVisitor {
       List<Issue> issues) {
     if (documentedParams.isEmpty() && !declaredParams.isEmpty()) {
       issues.add(
-          new Issue(
+          Issue.create(
+              INCONSISTENT_DOCSTRING_CATEGORY,
               "incomplete docstring: the function parameters are not documented",
               docstringLiteral.getLocation()));
       return;
@@ -141,7 +148,8 @@ public class DocstringChecker extends SyntaxTreeVisitor {
     for (String param : declaredParams) {
       if (!documentedParams.contains(param)) {
         issues.add(
-            new Issue(
+            Issue.create(
+                INCONSISTENT_DOCSTRING_CATEGORY,
                 "incomplete docstring: parameter '" + param + "' not documented",
                 docstringLiteral.getLocation()));
       }
@@ -149,7 +157,8 @@ public class DocstringChecker extends SyntaxTreeVisitor {
     for (String param : documentedParams) {
       if (!declaredParams.contains(param)) {
         issues.add(
-            new Issue(
+            Issue.create(
+                INCONSISTENT_DOCSTRING_CATEGORY,
                 "inconsistent docstring: parameter '"
                     + param
                     + "' appears in docstring but not in function signature",
@@ -166,7 +175,8 @@ public class DocstringChecker extends SyntaxTreeVisitor {
               + "Documentation order: "
               + String.join(", ", documentedParams)
               + "\n";
-      issues.add(new Issue(message, docstringLiteral.getLocation()));
+      issues.add(
+          Issue.create(INCONSISTENT_DOCSTRING_CATEGORY, message, docstringLiteral.getLocation()));
     }
   }
 
@@ -185,6 +195,9 @@ public class DocstringChecker extends SyntaxTreeVisitor {
     }
     Location start = new Location(startLine, startColumn);
     Location end = new Location(startLine, startColumn + error.line.length() - 1);
-    return new Issue("invalid docstring format: " + error.message, new LocationRange(start, end));
+    return new Issue(
+        BAD_DOCSTRING_FORMAT_CATEGORY,
+        "bad docstring format: " + error.message,
+        new LocationRange(start, end));
   }
 }
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/Issue.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/Issue.java
index 435c47c312..0891857424 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/Issue.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/Issue.java
@@ -18,26 +18,27 @@ import com.google.devtools.build.lib.events.Location;
 
 /** An issue found by the linter. */
 public class Issue {
-  // TODO(skylark-team): Represent issues more efficiently than just by a string
+  public final String category;
   public final String message;
   public final LocationRange location;
 
-  public Issue(String message, LocationRange location) {
+  public Issue(String category, String message, LocationRange location) {
+    this.category = category;
     this.message = message;
     this.location = location;
   }
 
-  public Issue(String message, Location location) {
-    this(message, LocationRange.from(location));
+  public static Issue create(String category, String message, Location location) {
+    return new Issue(category, message, LocationRange.from(location));
   }
 
   @Override
   public String toString() {
-    return location + ": " + message;
+    return location + ": " + message + " [" + category + "]";
   }
 
   public String prettyPrint(String path) {
-    return path + ":" + location + ": " + message;
+    return path + ":" + toString();
   }
 
   public static int compareLocation(Issue i1, Issue i2) {
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/Linter.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/Linter.java
index 0296b3d293..d403ecf771 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/Linter.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/Linter.java
@@ -33,6 +33,7 @@ import java.util.Set;
  * <p>Most users of the linter library should only need to use this class.
  */
 public class Linter {
+  private static final String PARSE_ERROR_CATEGORY = "parse-error";
   /** Map of all checks and their names. */
   private static final ImmutableMap<String, Check> nameToCheck =
       ImmutableMap.<String, Check>builder()
@@ -77,7 +78,8 @@ public class Linter {
         BuildFileAST.parseString(
             event -> {
               if (event.getKind() == EventKind.ERROR || event.getKind() == EventKind.WARNING) {
-                issues.add(new Issue(event.getMessage(), event.getLocation()));
+                issues.add(
+                    Issue.create(PARSE_ERROR_CATEGORY, event.getMessage(), event.getLocation()));
               }
             },
             content);
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/LoadStatementChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/LoadStatementChecker.java
index 5c33d9caee..ce8fa3c673 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/LoadStatementChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/LoadStatementChecker.java
@@ -22,6 +22,8 @@ import java.util.List;
 
 /** Checks that load statements are at the top of a file (after the docstring). */
 public class LoadStatementChecker {
+  private static final String LOAD_AT_TOP_CATEGORY = "load-at-top";
+
   private LoadStatementChecker() {}
 
   public static List<Issue> check(BuildFileAST ast) {
@@ -34,7 +36,8 @@ public class LoadStatementChecker {
       if (statement instanceof LoadStatement) {
         if (!loadStatementsExpected) {
           issues.add(
-              new Issue(
+              Issue.create(
+                  LOAD_AT_TOP_CATEGORY,
                   "load statement should be at the top of the file (after the docstring)",
                   statement.getLocation()));
         }
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/NamingConventionsChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/NamingConventionsChecker.java
index e796a1d9a1..92bda52ec6 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/NamingConventionsChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/NamingConventionsChecker.java
@@ -46,8 +46,11 @@ import java.util.List;
  */
 // TODO(skylark-team): Check that UPPERCASE_VARIABLES are never mutated
 public class NamingConventionsChecker extends AstVisitorWithNameResolution {
+  private static final String NAME_WITH_WRONG_CASE_CATEGORY = "name-with-wrong-case";
+  private static final String CONFUSING_NAME_CATEGORY = "confusing-name";
   private static final ImmutableList<String> CONFUSING_NAMES = ImmutableList.of("O", "I", "l");
   private static final ImmutableSet<String> BUILTIN_NAMES;
+
   private final List<Issue> issues = new ArrayList<>();
 
   static {
@@ -84,7 +87,8 @@ public class NamingConventionsChecker extends AstVisitorWithNameResolution {
   private void checkSnakeCase(String name, Location location) {
     if (!isSnakeCase(name)) {
       issues.add(
-          new Issue(
+          Issue.create(
+              NAME_WITH_WRONG_CASE_CATEGORY,
               "identifier '"
                   + name
                   + "' should be lower_snake_case (for variables)"
@@ -95,33 +99,44 @@ public class NamingConventionsChecker extends AstVisitorWithNameResolution {
 
   private void checkLowerSnakeCase(String name, Location location) {
     if (!isLowerSnakeCase(name)) {
-      issues.add(new Issue("identifier '" + name + "' should be lower_snake_case", location));
+      issues.add(
+          Issue.create(
+              NAME_WITH_WRONG_CASE_CATEGORY,
+              "identifier '" + name + "' should be lower_snake_case",
+              location));
     }
   }
 
   private void checkProviderName(String name, Location location) {
     if (!isUpperCamelCase(name)) {
-      issues.add(new Issue("provider name '" + name + "' should be UpperCamelCase", location));
+      issues.add(
+          Issue.create(
+              NAME_WITH_WRONG_CASE_CATEGORY,
+              "provider name '" + name + "' should be UpperCamelCase",
+              location));
     }
   }
 
   private void checkNameNotConfusing(String name, Location location) {
     if (CONFUSING_NAMES.contains(name)) {
       issues.add(
-          new Issue(
+          Issue.create(
+              CONFUSING_NAME_CATEGORY,
               "never use 'l', 'I', or 'O' as names "
                   + "(they're too easily confused with 'I', 'l', or '0')",
               location));
     }
     if (BUILTIN_NAMES.contains(name)) {
       issues.add(
-          new Issue(
+          Issue.create(
+              CONFUSING_NAME_CATEGORY,
               "identifier '" + name + "' shadows a builtin; please pick a different name",
               location));
     }
     if (name.chars().allMatch(c -> c == '_') && name.length() >= 2) {
       issues.add(
-          new Issue(
+          Issue.create(
+              CONFUSING_NAME_CATEGORY,
               "identifier '"
                   + name
                   + "' consists only of underscores; please pick a different name",
@@ -133,7 +148,8 @@ public class NamingConventionsChecker extends AstVisitorWithNameResolution {
   void use(Identifier identifier) {
     if (identifier.getName().equals("_")) {
       issues.add(
-          new Issue(
+          Issue.create(
+              CONFUSING_NAME_CATEGORY,
               "don't use '_' as an identifier, only to ignore the result in an assignment",
               identifier.getLocation()));
     }
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/StatementWithoutEffectChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/StatementWithoutEffectChecker.java
index 842cc6cf24..ba97ab2719 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/StatementWithoutEffectChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/StatementWithoutEffectChecker.java
@@ -28,6 +28,8 @@ import java.util.List;
 
 /** Checks for statements that have no effect. */
 public class StatementWithoutEffectChecker extends SyntaxTreeVisitor {
+  private static final String NO_EFFECT_CATEGORY = "no-effect";
+
   private final List<Issue> issues = new ArrayList<>();
   private boolean hasEffect = false;
   private boolean topLevel = true;
@@ -77,7 +79,7 @@ public class StatementWithoutEffectChecker extends SyntaxTreeVisitor {
       // list]
       return;
     }
-    issues.add(new Issue("expression result not used", node.getLocation()));
+    issues.add(Issue.create(NO_EFFECT_CATEGORY, "expression result not used", node.getLocation()));
   }
 
   @Override
diff --git a/src/tools/skylark/java/com/google/devtools/skylark/skylint/UsageChecker.java b/src/tools/skylark/java/com/google/devtools/skylark/skylint/UsageChecker.java
index db185ee40b..36614e75ba 100644
--- a/src/tools/skylark/java/com/google/devtools/skylark/skylint/UsageChecker.java
+++ b/src/tools/skylark/java/com/google/devtools/skylark/skylint/UsageChecker.java
@@ -39,6 +39,9 @@ import java.util.Set;
 
 /** Checks that every import, private function or variable definition is used somewhere. */
 public class UsageChecker extends AstVisitorWithNameResolution {
+  private static final String UNUSED_BINDING_CATEGORY = "unused-binding";
+  private static final String UNINITIALIZED_VARIABLE_CATEGORY = "uninitialized-variable";
+
   private final List<Issue> issues = new ArrayList<>();
   private UsageInfo ui = UsageInfo.empty();
   private final SetMultimap<Integer, Wrapper<ASTNode>> idToAllDefinitions =
@@ -159,7 +162,7 @@ public class UsageChecker extends AstVisitorWithNameResolution {
       // symbol might be loaded in another file
       return;
     }
-    String message = "unused definition of '" + name + "'";
+    String message = "unused binding of '" + name + "'";
     if (nameInfo.kind == Kind.PARAMETER) {
       message +=
           ". If this is intentional, "
@@ -168,15 +171,18 @@ public class UsageChecker extends AstVisitorWithNameResolution {
       message += ". If this is intentional, you can use '_' or rename it to '_" + name + "'.";
     }
     for (Wrapper<ASTNode> definition : unusedDefinitions) {
-      issues.add(new Issue(message, unwrapNode(definition).getLocation()));
+      issues.add(
+          Issue.create(UNUSED_BINDING_CATEGORY, message, unwrapNode(definition).getLocation()));
     }
   }
 
   private void checkInitialized(NameInfo info, Identifier node) {
     if (ui.reachable && !ui.initializedIdentifiers.contains(info.id) && info.kind != Kind.BUILTIN) {
       issues.add(
-          new Issue(
-              "identifier '" + info.name + "' may not have been initialized", node.getLocation()));
+          Issue.create(
+              UNINITIALIZED_VARIABLE_CATEGORY,
+              "variable '" + info.name + "' may not have been initialized",
+              node.getLocation()));
     }
   }
 
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/BadOperationCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/BadOperationCheckerTest.java
index 00138b6b6c..ce121ffb59 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/BadOperationCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/BadOperationCheckerTest.java
@@ -37,29 +37,45 @@ public class BadOperationCheckerTest {
   @Test
   public void dictionaryLiteralPlusOperator() {
     Truth.assertThat(findIssues("{} + foo").toString())
-        .contains("1:1-1:8: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:1-1:8: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
     Truth.assertThat(findIssues("foo + {}").toString())
-        .contains("1:1-1:8: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:1-1:8: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
     Truth.assertThat(findIssues("foo += {}").toString())
-        .contains("1:1-1:9: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:1-1:9: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
   }
 
   @Test
   public void dictionaryComprehensionPlusOperator() {
     Truth.assertThat(findIssues("{k:v for k,v in []} + foo").toString())
-        .contains("1:1-1:25: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:1-1:25: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
     Truth.assertThat(findIssues("foo + {k:v for k,v in []}").toString())
-        .contains("1:1-1:25: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:1-1:25: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
     Truth.assertThat(findIssues("foo += {k:v for k,v in []}").toString())
-        .contains("1:1-1:26: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:1-1:26: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
   }
 
   @Test
   public void dictionaryPlusOperatorNested() {
     Truth.assertThat(findIssues("foo + ({} + bar)").toString())
-        .contains("1:7-1:16: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:7-1:16: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
     Truth.assertThat(findIssues("foo + (bar + {})").toString())
-        .contains("1:7-1:16: '+' operator is deprecated and should not be used on dictionaries");
+        .contains(
+            "1:7-1:16: '+' operator is deprecated and should not be used on dictionaries"
+                + " [deprecated-plus-dict]");
   }
 
   @Test
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java
index f10aba0391..c522dcbee4 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/ControlFlowCheckerTest.java
@@ -51,7 +51,9 @@ public class ControlFlowCheckerTest {
                     "  else:",
                     "    return x")
                 .toString())
-        .contains("1:1-5:12: some but not all execution paths of 'some_function' return a value");
+        .contains(
+            "1:1-5:12: some but not all execution paths of 'some_function' return a value"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -65,8 +67,13 @@ public class ControlFlowCheckerTest {
                 "    return # missing value")
             .toString();
     Truth.assertThat(messages)
-        .contains("1:1-5:26: some but not all execution paths of 'some_function' return a value");
-    Truth.assertThat(messages).contains("5:5-5:10: return value missing");
+        .contains(
+            "1:1-5:26: some but not all execution paths of 'some_function' return a value"
+                + " [missing-return-value]");
+    Truth.assertThat(messages)
+        .contains(
+            "5:5-5:10: return value missing (you can `return None` if this is desired)"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -81,7 +88,9 @@ public class ControlFlowCheckerTest {
                     "  else:",
                     "    return not x")
                 .toString())
-        .contains("1:1-7:16: some but not all execution paths of 'f' return a value");
+        .contains(
+            "1:1-7:16: some but not all execution paths of 'f' return a value"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -97,7 +106,9 @@ public class ControlFlowCheckerTest {
                     "  else:",
                     "    return x")
                 .toString())
-        .contains("1:1-8:12: some but not all execution paths of 'f' return a value");
+        .contains(
+            "1:1-8:12: some but not all execution paths of 'f' return a value"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -110,7 +121,9 @@ public class ControlFlowCheckerTest {
                     "  elif not x:",
                     "    return not x")
                 .toString())
-        .contains("1:1-5:16: some but not all execution paths of 'some_function' return a value");
+        .contains(
+            "1:1-5:16: some but not all execution paths of 'some_function' return a value"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -123,7 +136,9 @@ public class ControlFlowCheckerTest {
                     "  print('foo')",
                     "  # return missing here")
                 .toString())
-        .contains("1:1-5:23: some but not all execution paths of 'some_function' return a value");
+        .contains(
+            "1:1-5:23: some but not all execution paths of 'some_function' return a value"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -136,7 +151,9 @@ public class ControlFlowCheckerTest {
                     "  print('foo')",
                     "  # return missing here")
                 .toString())
-        .contains("1:1-5:23: some but not all execution paths of 'some_function' return a value");
+        .contains(
+            "1:1-5:23: some but not all execution paths of 'some_function' return a value"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -149,8 +166,13 @@ public class ControlFlowCheckerTest {
                 "  return x")
             .toString();
     Truth.assertThat(messages)
-        .contains("1:1-4:10: some but not all execution paths of 'some_function' return a value");
-    Truth.assertThat(messages).contains("3:5-3:10: return value missing");
+        .contains(
+            "1:1-4:10: some but not all execution paths of 'some_function' return a value"
+                + " [missing-return-value]");
+    Truth.assertThat(messages)
+        .contains(
+            "3:5-3:10: return value missing (you can `return None` if this is desired)"
+                + " [missing-return-value]");
   }
 
   @Test
@@ -164,7 +186,7 @@ public class ControlFlowCheckerTest {
                 "    fail('fail')",
                 "  print('This line is unreachable')")
             .toString();
-    Truth.assertThat(messages).contains("6:3-6:35: unreachable statement");
+    Truth.assertThat(messages).contains("6:3-6:35: unreachable statement [unreachable-statement]");
   }
 
   @Test
@@ -190,7 +212,7 @@ public class ControlFlowCheckerTest {
                 "      continue",
                 "    print('unreachable')")
             .toString();
-    Truth.assertThat(messages).contains("7:5-7:24: unreachable statement");
+    Truth.assertThat(messages).contains("7:5-7:24: unreachable statement [unreachable-statement]");
   }
 
   @Test
@@ -280,7 +302,8 @@ public class ControlFlowCheckerTest {
             "    return x",
             "  # no else branch but doesn't matter since it's unreachable");
     Truth.assertThat(issues).hasSize(1);
-    Truth.assertThat(issues.toString()).contains("7:3-7:14: unreachable statement");
+    Truth.assertThat(issues.toString())
+        .contains("7:3-7:14: unreachable statement [unreachable-statement]");
   }
 
   @Test
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DeprecationCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DeprecationCheckerTest.java
index 5d55eb7a57..cd12f4a7c8 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DeprecationCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DeprecationCheckerTest.java
@@ -54,9 +54,12 @@ public class DeprecationCheckerTest {
                 "  The deprecation should really be documented in a 'Deprecated:' section",
                 "  but the linter should recognize this kind of deprecation as well'''")
             .toString();
-    Truth.assertThat(errorMessages).contains("2:3: usage of 'g' is deprecated: reason");
     Truth.assertThat(errorMessages)
-        .contains("3:3: usage of 'h' is deprecated: This function is DEPRECATED for some reason.");
+        .contains("2:3: usage of 'g' is deprecated: reason [deprecated-symbol]");
+    Truth.assertThat(errorMessages)
+        .contains(
+            "3:3: usage of 'h' is deprecated: This function is DEPRECATED for some reason."
+                + " [deprecated-symbol]");
   }
 
   @Test
@@ -72,7 +75,8 @@ public class DeprecationCheckerTest {
                 "  Deprecated:",
                 "    reason'''")
             .toString();
-    Truth.assertThat(errorMessages).contains("2:7: usage of 'g' is deprecated: reason");
+    Truth.assertThat(errorMessages)
+        .contains("2:7: usage of 'g' is deprecated: reason [deprecated-symbol]");
   }
 
   @Test
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java
index 8b399ccd34..377f0eed7c 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/DocstringCheckerTests.java
@@ -40,8 +40,10 @@ public class DocstringCheckerTests {
     String errorMessage =
         findIssues("# no module docstring", "def function():", "  pass # no function docstring")
             .toString();
-    Truth.assertThat(errorMessage).contains("1:1-2:1: file has no module docstring");
-    Truth.assertThat(errorMessage).contains("2:1-3:30: function 'function' has no docstring");
+    Truth.assertThat(errorMessage)
+        .contains("1:1-2:1: file has no module docstring [missing-docstring]");
+    Truth.assertThat(errorMessage)
+        .contains("2:1-3:30: function 'function' has no docstring [missing-docstring]");
   }
 
   @Test
@@ -57,7 +59,9 @@ public class DocstringCheckerTests {
             "  pass");
     Truth.assertThat(errors).hasSize(1);
     Truth.assertThat(errors.toString())
-        .contains("3:3-6:3: incomplete docstring: the function parameters are not documented");
+        .contains(
+            "3:3-6:3: incomplete docstring: the function parameters are not documented"
+                + " [inconsistent-docstring]");
   }
 
   @Test
@@ -73,9 +77,13 @@ public class DocstringCheckerTests {
                 "  pass")
             .toString();
     Truth.assertThat(errorMessage)
-        .contains("2:3-6:5: incomplete docstring: parameter 'foo' not documented");
+        .contains(
+            "2:3-6:5: incomplete docstring: parameter 'foo' not documented"
+                + " [inconsistent-docstring]");
     Truth.assertThat(errorMessage)
-        .contains("2:3-6:5: incomplete docstring: parameter 'baz' not documented");
+        .contains(
+            "2:3-6:5: incomplete docstring: parameter 'baz' not documented"
+                + " [inconsistent-docstring]");
   }
 
   @Test
@@ -95,11 +103,11 @@ public class DocstringCheckerTests {
     Truth.assertThat(errorMessage)
         .contains(
             "2:3-8:5: inconsistent docstring: parameter 'foo' appears in docstring"
-                + " but not in function signature");
+                + " but not in function signature [inconsistent-docstring]");
     Truth.assertThat(errorMessage)
         .contains(
             "2:3-8:5: inconsistent docstring: parameter 'baz' appears in docstring"
-                + " but not in function signature");
+                + " but not in function signature [inconsistent-docstring]");
   }
 
   @Test
@@ -120,7 +128,8 @@ public class DocstringCheckerTests {
             "2:3-7:5:"
                 + " inconsistent docstring: order of parameters differs from function signature\n"
                 + "Declaration order:   p1, p2\n"
-                + "Documentation order: p2, p1");
+                + "Documentation order: p2, p1\n"
+                + " [inconsistent-docstring]");
   }
 
   @Test
@@ -128,8 +137,8 @@ public class DocstringCheckerTests {
     String errorMessage = findIssues("\"\"\"summary", "missing blank line\"\"\"").toString();
     Truth.assertThat(errorMessage)
         .contains(
-            "2:1-2:18: invalid docstring format: "
-                + "the one-line summary should be followed by a blank line");
+            "2:1-2:18: bad docstring format: "
+                + "the one-line summary should be followed by a blank line [bad-docstring-format]");
 
     errorMessage =
         findIssues(
@@ -142,8 +151,9 @@ public class DocstringCheckerTests {
             .toString();
     Truth.assertThat(errorMessage)
         .contains(
-            "5:1-5:29: invalid docstring format: "
-                + "line indented too little (here: 1 spaces; expected: 2 spaces)");
+            "5:1-5:29: bad docstring format: "
+                + "line indented too little (here: 1 spaces; expected: 2 spaces)"
+                + " [bad-docstring-format]");
   }
 
   @Test
@@ -159,7 +169,9 @@ public class DocstringCheckerTests {
             "  return True");
     Truth.assertThat(errors).hasSize(1);
     Truth.assertThat(errors.toString())
-        .contains("3:3-6:5: incomplete docstring: the return value is not documented");
+        .contains(
+            "3:3-6:5: incomplete docstring: the return value is not documented"
+                + " [inconsistent-docstring]");
   }
 
   @Test
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LinterTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LinterTest.java
index 148aa4845e..96ff5d47f5 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LinterTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LinterTest.java
@@ -53,6 +53,6 @@ public class LinterTest {
         .contains("should be lower_snake_case"); // naming conventions checker
     Truth.assertThat(errorMessages)
         .contains("expression result not used"); // checker statements without effect
-    Truth.assertThat(errorMessages).contains("unused definition of"); // usage checker
+    Truth.assertThat(errorMessages).contains("unused binding of"); // usage checker
   }
 }
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LoadStatementCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LoadStatementCheckerTest.java
index c6cb41b543..35857e3722 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LoadStatementCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/LoadStatementCheckerTest.java
@@ -59,7 +59,8 @@ public class LoadStatementCheckerTest {
             .toString();
     Truth.assertThat(errorMessage)
         .contains(
-            "3:1-3:23: load statement should be at the top of the file (after the docstring)");
+            "3:1-3:23: load statement should be at the top of the file (after the docstring)"
+                + " [load-at-top]");
     errorMessage =
         findIssues(
                 "'''Docstring'''",
@@ -69,6 +70,7 @@ public class LoadStatementCheckerTest {
             .toString();
     Truth.assertThat(errorMessage)
         .contains(
-            "4:1-4:23: load statement should be at the top of the file (after the docstring)");
+            "4:1-4:23: load statement should be at the top of the file (after the docstring)"
+                + " [load-at-top]");
   }
 }
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/NamingConventionsCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/NamingConventionsCheckerTest.java
index 0dc837c432..6361705c29 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/NamingConventionsCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/NamingConventionsCheckerTest.java
@@ -46,13 +46,15 @@ public class NamingConventionsCheckerTest {
     Truth.assertThat(errorMessage)
         .contains(
             "'badGlobalVariableName' should be lower_snake_case (for variables)"
-                + " or UPPER_SNAKE_CASE (for constants)");
-    Truth.assertThat(errorMessage).contains("'BAD_FUNCTION_NAME' should be lower_snake_case");
-    Truth.assertThat(errorMessage).contains("'BadParameterName' should be lower_snake_case");
+                + " or UPPER_SNAKE_CASE (for constants) [name-with-wrong-case]");
+    Truth.assertThat(errorMessage)
+        .contains("'BAD_FUNCTION_NAME' should be lower_snake_case [name-with-wrong-case]");
+    Truth.assertThat(errorMessage)
+        .contains("'BadParameterName' should be lower_snake_case [name-with-wrong-case]");
     Truth.assertThat(errorMessage)
         .contains(
             "'badLocalVariableName' should be lower_snake_case (for variables)"
-                + " or UPPER_SNAKE_CASE (for constants)");
+                + " or UPPER_SNAKE_CASE (for constants) [name-with-wrong-case]");
   }
 
   @Test
@@ -61,11 +63,13 @@ public class NamingConventionsCheckerTest {
     Truth.assertThat(errorMessage)
         .contains(
             "never use 'l', 'I', or 'O' as names"
-                + " (they're too easily confused with 'I', 'l', or '0')");
+                + " (they're too easily confused with 'I', 'l', or '0') [confusing-name]");
     Truth.assertThat(errorMessage)
-        .contains("identifier 'fail' shadows a builtin; please pick a different name");
+        .contains(
+            "identifier 'fail' shadows a builtin; please pick a different name [confusing-name]");
     Truth.assertThat(errorMessage)
-        .contains("identifier 'True' shadows a builtin; please pick a different name");
+        .contains(
+            "identifier 'True' shadows a builtin; please pick a different name [confusing-name]");
   }
 
   @Test
@@ -74,11 +78,13 @@ public class NamingConventionsCheckerTest {
     Truth.assertThat(findIssues("_ = 1", "print(_)").toString())
         .contains(
             "2:7-2:7:"
-                + " don't use '_' as an identifier, only to ignore the result in an assignment");
+                + " don't use '_' as an identifier, only to ignore the result in an assignment"
+                + " [confusing-name]");
     Truth.assertThat(findIssues("__ = 1").toString())
         .contains(
             "1:1-1:2:"
-                + " identifier '__' consists only of underscores; please pick a different name");
+                + " identifier '__' consists only of underscores; please pick a different name"
+                + " [confusing-name]");
   }
 
   @Test
@@ -102,7 +108,7 @@ public class NamingConventionsCheckerTest {
   public void testProviderNameMustBeCamelCase() throws Exception {
     Truth.assertThat(findIssues("FooBar = provider()")).isEmpty();
     Truth.assertThat(findIssues("foo_bar = provider()").toString())
-        .contains("provider name 'foo_bar' should be UpperCamelCase");
+        .contains("provider name 'foo_bar' should be UpperCamelCase [name-with-wrong-case]");
   }
 
   @Test
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/StatementWithoutEffectCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/StatementWithoutEffectCheckerTest.java
index d160d2357e..beac94c3c7 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/StatementWithoutEffectCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/StatementWithoutEffectCheckerTest.java
@@ -38,12 +38,12 @@ public class StatementWithoutEffectCheckerTest {
   public void reportUselessExpressionStatements() throws Exception {
     String messages =
         findIssues("1", "len", "'string'", "'a'.len", "1 + 1", "[1, 2, 3]").toString();
-    Truth.assertThat(messages).contains("1:1-1:1: expression result not used");
-    Truth.assertThat(messages).contains("2:1-2:3: expression result not used");
-    Truth.assertThat(messages).contains("3:1-3:8: expression result not used");
-    Truth.assertThat(messages).contains("4:1-4:7: expression result not used");
-    Truth.assertThat(messages).contains("5:1-5:5: expression result not used");
-    Truth.assertThat(messages).contains("6:1-6:9: expression result not used");
+    Truth.assertThat(messages).contains("1:1-1:1: expression result not used [no-effect]");
+    Truth.assertThat(messages).contains("2:1-2:3: expression result not used [no-effect]");
+    Truth.assertThat(messages).contains("3:1-3:8: expression result not used [no-effect]");
+    Truth.assertThat(messages).contains("4:1-4:7: expression result not used [no-effect]");
+    Truth.assertThat(messages).contains("5:1-5:5: expression result not used [no-effect]");
+    Truth.assertThat(messages).contains("6:1-6:9: expression result not used [no-effect]");
   }
 
   @Test
@@ -58,7 +58,7 @@ public class StatementWithoutEffectCheckerTest {
             findIssues(
                     "def f():", "  [print(x) for x in range(5)] # should be replaced by for-loop")
                 .toString())
-        .contains("2:3-2:30: expression result not used");
+        .contains("2:3-2:30: expression result not used [no-effect]");
   }
 
   @Test
diff --git a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/UsageCheckerTest.java b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/UsageCheckerTest.java
index de61011a0e..b477cce1a8 100644
--- a/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/UsageCheckerTest.java
+++ b/src/tools/skylark/javatests/com/google/devtools/skylark/skylint/UsageCheckerTest.java
@@ -38,37 +38,41 @@ public class UsageCheckerTest {
   @Test
   public void reportUnusedImports() throws Exception {
     String message = findIssues("load('foo', 'x', 'y', _z = 'Z')").toString();
-    Truth.assertThat(message).contains("1:13-1:15: unused definition of 'x'");
-    Truth.assertThat(message).contains("1:18-1:20: unused definition of 'y'");
-    Truth.assertThat(message).contains("1:23-1:24: unused definition of '_z'");
+    Truth.assertThat(message).contains("1:13-1:15: unused binding of 'x' [unused-binding]");
+    Truth.assertThat(message).contains("1:18-1:20: unused binding of 'y' [unused-binding]");
+    Truth.assertThat(message).contains("1:23-1:24: unused binding of '_z' [unused-binding]");
   }
 
   @Test
   public void reportUnusedGlobals() throws Exception {
     String message = findIssues("_UNUSED = len([])", "def _unused(): pass").toString();
-    Truth.assertThat(message).contains("1:1-1:7: unused definition of '_UNUSED'");
-    Truth.assertThat(message).contains("2:5-2:11: unused definition of '_unused'");
+    Truth.assertThat(message).contains("1:1-1:7: unused binding of '_UNUSED' [unused-binding]");
+    Truth.assertThat(message).contains("2:5-2:11: unused binding of '_unused' [unused-binding]");
   }
 
   @Test
   public void reportUnusedLocals() throws Exception {
     String message = findIssues("def some_function(param):", "  local, local2 = 1, 3").toString();
-    Truth.assertThat(message).contains("1:19-1:23: unused definition of 'param'");
+    Truth.assertThat(message).contains("1:19-1:23: unused binding of 'param'");
     Truth.assertThat(message)
-        .contains("you can add `_ignore = [<param1>, <param2>, ...]` to the function body.");
-    Truth.assertThat(message).contains("2:3-2:7: unused definition of 'local'");
-    Truth.assertThat(message).contains("you can use '_' or rename it to '_local'");
-    Truth.assertThat(message).contains("2:10-2:15: unused definition of 'local2'");
-    Truth.assertThat(message).contains("you can use '_' or rename it to '_local2'");
+        .contains(
+            "you can add `_ignore = [<param1>, <param2>, ...]` to the function body."
+                + " [unused-binding]");
+    Truth.assertThat(message).contains("2:3-2:7: unused binding of 'local'");
+    Truth.assertThat(message)
+        .contains("you can use '_' or rename it to '_local'. [unused-binding]");
+    Truth.assertThat(message).contains("2:10-2:15: unused binding of 'local2'");
+    Truth.assertThat(message)
+        .contains("you can use '_' or rename it to '_local2'. [unused-binding]");
   }
 
   @Test
   public void reportUnusedComprehensionVariable() throws Exception {
     String message = findIssues("[[2 for y in []] for x in []]").toString();
-    Truth.assertThat(message).contains("1:9-1:9: unused definition of 'y'");
-    Truth.assertThat(message).contains("you can use '_' or rename it to '_y'");
-    Truth.assertThat(message).contains("1:22-1:22: unused definition of 'x'");
-    Truth.assertThat(message).contains("you can use '_' or rename it to '_x'");
+    Truth.assertThat(message).contains("1:9-1:9: unused binding of 'y'");
+    Truth.assertThat(message).contains("you can use '_' or rename it to '_y'. [unused-binding]");
+    Truth.assertThat(message).contains("1:22-1:22: unused binding of 'x'");
+    Truth.assertThat(message).contains("you can use '_' or rename it to '_x'. [unused-binding]");
   }
 
   @Test
@@ -79,19 +83,19 @@ public class UsageCheckerTest {
                     "  x = [[] for x in []]",
                     "  print(x)")
                 .toString())
-        .contains("2:15-2:15: unused definition of 'x'");
+        .contains("2:15-2:15: unused binding of 'x'");
   }
 
   @Test
   public void reportShadowedVariable() throws Exception {
     Truth.assertThat(findIssues("def some_function():", "  x = [x for x in []]").toString())
-        .contains("2:3-2:3: unused definition of 'x'");
+        .contains("2:3-2:3: unused binding of 'x'");
   }
 
   @Test
   public void reportReassignedUnusedVariable() throws Exception {
     Truth.assertThat(findIssues("def some_function():", "  x = 1", "  x += 2").toString())
-        .contains("3:3-3:3: unused definition of 'x'");
+        .contains("3:3-3:3: unused binding of 'x'");
   }
 
   @Test
@@ -106,7 +110,7 @@ public class UsageCheckerTest {
                     "    x = 4",
                     "  print(x)")
                 .toString())
-        .contains("2:3-2:3: unused definition of 'x'");
+        .contains("2:3-2:3: unused binding of 'x'");
   }
 
   @Test
@@ -118,7 +122,7 @@ public class UsageCheckerTest {
                 "    print(x)",
                 "    x = 2")
             .toString();
-    Truth.assertThat(messages).contains("4:5-4:5: unused definition of 'x'");
+    Truth.assertThat(messages).contains("4:5-4:5: unused binding of 'x'");
   }
 
   @Test
@@ -135,14 +139,16 @@ public class UsageCheckerTest {
                 "  y += 2",
                 "  print(y)")
             .toString();
-    Truth.assertThat(message).contains("8:3-8:3: identifier 'y' may not have been initialized");
+    Truth.assertThat(message)
+        .contains("8:3-8:3: variable 'y' may not have been initialized [uninitialized-variable]");
   }
 
   @Test
   public void reportUninitializedAfterForLoop() throws Exception {
     String message =
         findIssues("def some_function():", "  for _ in []:", "    y = 1", "  print(y)").toString();
-    Truth.assertThat(message).contains("4:9-4:9: identifier 'y' may not have been initialized");
+    Truth.assertThat(message)
+        .contains("4:9-4:9: variable 'y' may not have been initialized [uninitialized-variable]");
   }
 
   @Test