Fix LexicographicalAnnotationAttributeListing string sorting

error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/LexicographicalAnnotationAttributeListing.java

@@ -1,5 +1,6 @@
 package tech.picnic.errorprone.bugpatterns;
 
+import static com.google.common.collect.ImmutableList.toImmutableList;
 import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
 import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
 import static com.google.errorprone.BugPattern.StandardTags.STYLE;
@@ -9,6 +10,7 @@
 import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
 
 import com.google.auto.service.AutoService;
+import com.google.common.base.Splitter;
 import com.google.common.collect.Comparators;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
@@ -71,6 +73,12 @@ public final class LexicographicalAnnotationAttributeListing extends BugChecker
   private static final String FLAG_PREFIX = "LexicographicalAnnotationAttributeListing:";
   private static final String INCLUDED_ANNOTATIONS_FLAG = FLAG_PREFIX + "Includes";
   private static final String EXCLUDED_ANNOTATIONS_FLAG = FLAG_PREFIX + "Excludes";
+  /**
+   * The splitter applied to string-typed annotation arguments prior to lexicographical sorting. By
+   * splitting on {@code =}, strings that represent e.g. inline Spring property declarations are
+   * properly sorted by key, then value.
+   */
+  private static final Splitter STRING_ARGUMENT_SPLITTER = Splitter.on('=');
 
   private final AnnotationAttributeMatcher matcher;
 
@@ -126,7 +134,7 @@ private static Optional<SuggestedFix.Builder> suggestSorting(
     }
 
     List<? extends ExpressionTree> actualOrdering = array.getInitializers();
-    ImmutableList<? extends ExpressionTree> desiredOrdering = doSort(actualOrdering, state);
+    ImmutableList<? extends ExpressionTree> desiredOrdering = doSort(actualOrdering);
     if (actualOrdering.equals(desiredOrdering)) {
       /* In the (presumably) common case the elements are already sorted. */
       return Optional.empty();
@@ -156,12 +164,12 @@ private static boolean canSort(Tree array, VisitorState state) {
   }
 
   private static ImmutableList<? extends ExpressionTree> doSort(
-      Iterable<? extends ExpressionTree> elements, VisitorState state) {
+      Iterable<? extends ExpressionTree> elements) {
     // XXX: Perhaps we should use `Collator` with `.setStrength(Collator.PRIMARY)` and
     // `getCollationKey`. Not clear whether that's worth the hassle at this point.
     return ImmutableList.sortedCopyOf(
         comparing(
-            e -> getStructure(e, state),
+            LexicographicalAnnotationAttributeListing::getStructure,
             Comparators.lexicographical(
                 Comparators.lexicographical(
                     String.CASE_INSENSITIVE_ORDER.thenComparing(naturalOrder())))),
@@ -173,38 +181,34 @@ private static ImmutableList<? extends ExpressionTree> doSort(
    * performed. This approach disregards e.g. irrelevant whitespace. It also allows special
    * structure within string literals to be respected.
    */
-  private static ImmutableList<ImmutableList<String>> getStructure(
-      ExpressionTree array, VisitorState state) {
+  private static ImmutableList<ImmutableList<String>> getStructure(ExpressionTree array) {
     ImmutableList.Builder<ImmutableList<String>> nodes = ImmutableList.builder();
 
     new TreeScanner<Void, Void>() {
       @Nullable
       @Override
-      public Void visitIdentifier(IdentifierTree node, @Nullable Void ctx) {
-        nodes.add(tokenize(node));
-        return super.visitIdentifier(node, ctx);
+      public Void visitIdentifier(IdentifierTree node, @Nullable Void unused) {
+        nodes.add(ImmutableList.of(node.getName().toString()));
+        return super.visitIdentifier(node, unused);
       }
 
       @Nullable
       @Override
-      public Void visitLiteral(LiteralTree node, @Nullable Void ctx) {
-        nodes.add(tokenize(node));
-        return super.visitLiteral(node, ctx);
+      public Void visitLiteral(LiteralTree node, @Nullable Void unused) {
+        Object value = ASTHelpers.constValue(node);
+        nodes.add(
+            value instanceof String
+                ? STRING_ARGUMENT_SPLITTER.splitToStream((String) value).collect(toImmutableList())
+                : ImmutableList.of(String.valueOf(value)));
+
+        return super.visitLiteral(node, unused);
       }
 
       @Nullable
       @Override
-      public Void visitPrimitiveType(PrimitiveTypeTree node, @Nullable Void ctx) {
-        nodes.add(tokenize(node));
-        return super.visitPrimitiveType(node, ctx);
-      }
-
-      private ImmutableList<String> tokenize(Tree node) {
-        /*
-         * Tokens are split on `=` so that e.g. inline Spring property declarations are properly
-         * sorted by key, then value.
-         */
-        return ImmutableList.copyOf(SourceCode.treeToString(node, state).split("=", -1));
+      public Void visitPrimitiveType(PrimitiveTypeTree node, @Nullable Void unused) {
+        nodes.add(ImmutableList.of(node.getPrimitiveTypeKind().toString()));
+        return super.visitPrimitiveType(node, unused);
       }
     }.scan(array, null);
 

error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/LexicographicalAnnotationAttributeListingTest.java

@@ -188,7 +188,7 @@ void replacement() {
             "    String[] value() default {};",
             "  }",
             "",
-            "  @Foo({\"b\", \"a\"})",
+            "  @Foo({\" \", \"\", \"b\", \"a\"})",
             "  A unsortedString();",
             "",
             "  @Foo(cls = {long.class, int.class})",
@@ -225,7 +225,7 @@ void replacement() {
             "    String[] value() default {};",
             "  }",
             "",
-            "  @Foo({\"a\", \"b\"})",
+            "  @Foo({\"\", \" \", \"a\", \"b\"})",
             "  A unsortedString();",
             "",
             "  @Foo(cls = {int.class, long.class})",