The class name to count map is never used, only its keys are. Replace with a set.

PiperOrigin-RevId: 551870873

Author: nanaze

src/com/google/javascript/jscomp/AbstractCompiler.java

@@ -50,7 +50,6 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.EnumSet;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Set;
 import org.jspecify.nullness.Nullable;
@@ -129,7 +128,7 @@ void afterPass(String passName) {}
   public abstract void setStringMap(VariableMap stringMap);
 
   /** Sets the css names found during compilation. */
-  public abstract void setCssNames(LinkedHashMap<String, Integer> newCssNames);
+  public abstract void setCssNames(Set<String> newCssNames);
 
   /** Sets the mapping for instrumentation parameter encoding. */
   public abstract void setInstrumentationMapping(VariableMap instrumentationMapping);

src/com/google/javascript/jscomp/Compiler.java

@@ -3507,11 +3507,8 @@ public SourceMap getSourceMap() {
   /** Ids for cross-module method stubbing, so that each method has a unique id. */
   private IdGenerator crossModuleIdGenerator = new IdGenerator();
 
-  /**
-   * Keys are arguments passed to getCssName() found during compilation; values are the number of
-   * times the key appeared as an argument to getCssName().
-   */
-  private @Nullable LinkedHashMap<String, Integer> cssNames = null;
+  /** Arguments passed to getCssName() found during compilation. */
+  private @Nullable Set<String> cssNames = null;
 
   /** The variable renaming map */
   private @Nullable VariableMap variableMap = null;
@@ -3558,7 +3555,7 @@ public void setStringMap(VariableMap stringMap) {
   }
 
   @Override
-  public void setCssNames(LinkedHashMap<String, Integer> cssNames) {
+  public void setCssNames(Set<String> cssNames) {
     this.cssNames = cssNames;
   }
 
@@ -3960,7 +3957,7 @@ protected static class CompilerState implements Serializable {
     private final int uniqueNameId;
     private final UniqueIdSupplier uniqueIdSupplier;
     private final LinkedHashSet<String> exportedNames;
-    private final LinkedHashMap<String, Integer> cssNames;
+    private final Set<String> cssNames;
     private final String idGeneratorMap;
     private final boolean transpiledFiles;
     private final IdGenerator crossModuleIdGenerator;

src/com/google/javascript/jscomp/DefaultPassConfig.java

@@ -76,9 +76,9 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import org.jspecify.nullness.Nullable;
 
@@ -1612,18 +1612,20 @@ compiler, new GoogleJsMessageIdGenerator(options.tcProjectId)
                   new CompilerPass() {
                     @Override
                     public void process(Node externs, Node jsRoot) {
-                      LinkedHashMap<String, Integer> newCssNames = null;
-                      if (options.gatherCssNames) {
-                        newCssNames = new LinkedHashMap<>();
-                      }
+                      Optional<ImmutableSet.Builder<String>> cssNames =
+                          options.gatherCssNames
+                              ? Optional.of(ImmutableSet.builder())
+                              : Optional.empty();
+
                       ReplaceCssNames pass =
                           new ReplaceCssNames(
                               compiler,
                               options.cssRenamingMap,
-                              newCssNames,
+                              cssName -> cssNames.ifPresent(builder -> builder.add(cssName)),
                               options.cssRenamingSkiplist);
                       pass.process(externs, jsRoot);
-                      compiler.setCssNames(newCssNames);
+
+                      compiler.setCssNames(cssNames.isPresent() ? cssNames.get().build() : null);
                     }
                   })
           .build();

src/com/google/javascript/jscomp/ReplaceCssNames.java

@@ -140,7 +140,7 @@ class ReplaceCssNames implements CompilerPass {
   private final AbstractCompiler compiler;
   private final AstFactory astFactory;
 
-  private final Map<String, Integer> cssNames;
+  private final CssNameCollector cssNameCollector;
 
   private final Map<String, String> cssNamesBySymbol;
 
@@ -150,15 +150,21 @@ class ReplaceCssNames implements CompilerPass {
 
   private final Set<String> skiplist;
 
+  /** Called for each class name seen when replacing. */
+  @FunctionalInterface
+  public interface CssNameCollector {
+    void add(String className);
+  }
+
   ReplaceCssNames(
       AbstractCompiler compiler,
       @Nullable CssRenamingMap symbolMap,
-      @Nullable Map<String, Integer> cssNames,
+      CssNameCollector cssNameCollector,
       @Nullable Set<String> skiplist) {
     this.compiler = compiler;
     this.astFactory = compiler.createAstFactory();
     this.symbolMap = symbolMap;
-    this.cssNames = cssNames;
+    this.cssNameCollector = cssNameCollector;
     this.skiplist = skiplist;
     this.cssNamesBySymbol = new LinkedHashMap<>();
     this.classesObjectsQualifiedNames = new LinkedHashSet<>();
@@ -322,12 +328,9 @@ private class TraversalState {
    * goog.getCssName('myComponent-highlight') will also work.
    */
   private void updateCssNamesCount(String cssClassName) {
-    if (cssNames != null) {
-      String[] parts = cssClassName.split("-", -1);
-      for (String element : parts) {
-        int count = cssNames.getOrDefault(element, 0);
-        cssNames.put(element, count + 1);
-      }
+    String[] parts = cssClassName.split("-", -1);
+    for (String element : parts) {
+      cssNameCollector.add(element);
     }
   }
 

src/com/google/javascript/jscomp/Result.java

@@ -19,7 +19,7 @@
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import java.util.Map;
+import java.util.Set;
 import org.jspecify.nullness.Nullable;
 
 /** Compilation results */
@@ -34,7 +34,7 @@ public class Result {
   public final VariableMap stringMap;
   public final VariableMap instrumentationMappings;
   public final SourceMap sourceMap;
-  public final Map<String, Integer> cssNames;
+  public final Set<String> cssNames;
   public final String externExport;
   public final String idGeneratorMap;
   public final boolean transpiledFiles;
@@ -49,7 +49,7 @@ public class Result {
       @Nullable VariableMap instrumentationMappings,
       @Nullable SourceMap sourceMap,
       String externExport,
-      @Nullable Map<String, Integer> cssNames,
+      @Nullable Set<String> cssNames,
       @Nullable String idGeneratorMap,
       boolean transpiledFiles) {
     this.success = errors.isEmpty();

test/com/google/javascript/jscomp/ReplaceCssNamesTest.java

@@ -26,8 +26,8 @@
 
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Sets;
 import com.google.javascript.rhino.Node;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 import org.junit.Before;
@@ -68,7 +68,7 @@ public final class ReplaceCssNamesTest extends CompilerTestCase {
   CssRenamingMap renamingMap;
   Set<String> skiplist;
 
-  Map<String, Integer> cssNames;
+  Set<String> cssNames;
 
   public ReplaceCssNamesTest() {
     super(
@@ -82,7 +82,7 @@ public ReplaceCssNamesTest() {
   @Override
   protected CompilerPass getProcessor(Compiler compiler) {
     return new ReplaceCssNames(
-        compiler, useReplacementMap ? renamingMap : null, cssNames, skiplist);
+        compiler, useReplacementMap ? renamingMap : null, cssNames::add, skiplist);
   }
 
   CssRenamingMap getPartialMap() {
@@ -109,7 +109,7 @@ public void setUp() throws Exception {
     super.setUp();
     enableTypeCheck();
     enableRewriteClosureCode();
-    cssNames = new HashMap<>();
+    cssNames = Sets.newHashSet();
     useReplacementMap = true;
     renamingMap = getPartialMap();
   }
@@ -179,16 +179,8 @@ public void testDoNotUseReplacementMap() {
     test(
         "setClass(goog.getCssName('active-buttonbar'))", //
         "setClass('active-buttonbar')");
-    ImmutableMap<String, Integer> expected =
-        new ImmutableMap.Builder<String, Integer>()
-            .put("goog", 2)
-            .put("footer", 1)
-            .put("active", 2)
-            .put("colorswatch", 1)
-            .put("disabled", 1)
-            .put("buttonbar", 1)
-            .buildOrThrow();
-    assertThat(cssNames).isEqualTo(expected);
+    assertThat(cssNames)
+        .containsExactly("goog", "footer", "active", "colorswatch", "disabled", "buttonbar");
   }
 
   @Test
@@ -217,13 +209,7 @@ private void oneArgWithSimpleStringLiterals() {
     test(
         "setClass(goog.getCssName('elephant'))", //
         "setClass('e')");
-    ImmutableMap<String, Integer> expected =
-        new ImmutableMap.Builder<String, Integer>()
-            .put("buttonbar", 1)
-            .put("colorswatch", 1)
-            .put("elephant", 1)
-            .buildOrThrow();
-    assertThat(cssNames).isEqualTo(expected);
+    assertThat(cssNames).containsExactly("buttonbar", "colorswatch", "elephant");
   }
 
   @Test
@@ -241,16 +227,8 @@ private void oneArgWithCompositeClassNames() {
     test(
         "setClass(goog.getCssName('active-buttonbar'))", //
         "setClass('a-b')");
-    ImmutableMap<String, Integer> expected =
-        new ImmutableMap.Builder<String, Integer>()
-            .put("goog", 2)
-            .put("footer", 1)
-            .put("active", 2)
-            .put("colorswatch", 1)
-            .put("disabled", 1)
-            .put("buttonbar", 1)
-            .buildOrThrow();
-    assertThat(cssNames).isEqualTo(expected);
+    assertThat(cssNames)
+        .containsExactly("goog", "footer", "active", "colorswatch", "disabled", "buttonbar");
   }
 
   @Test
@@ -382,7 +360,7 @@ public void println(CheckLevel level, JSError error) {}
     compiler.setErrorManager(errorMan);
     Node root = compiler.parseTestCode(input);
     useReplacementMap = false;
-    ReplaceCssNames replacer = new ReplaceCssNames(compiler, null, null, null);
+    ReplaceCssNames replacer = new ReplaceCssNames(compiler, null, unused -> {}, null);
     replacer.process(null, root);
     assertThat(compiler.toSource(root)).isEqualTo("[\"test\",base+\"-active\"]");
     assertWithMessage("There should be no errors").that(errorMan.getErrorCount()).isEqualTo(0);
@@ -472,7 +450,7 @@ public void testVariableReferencesToCssClasses() {
                 // name like this rather than creating an alias variable named `foo`.
                 "var x = foo_styles_css.classes.Bar"));
     test(srcs(cssVarsDefinition, importer), expected(cssVarsExpected, importer));
-    assertThat(cssNames).containsExactly("fooStylesBar", 1);
+    assertThat(cssNames).containsExactly("fooStylesBar");
   }
 
   @Test
@@ -524,7 +502,7 @@ public void testMixedVariableAndStringReferences() {
                 "var x = foo_styles_css.classes.Bar;",
                 "var y = 'a';"));
     test(srcs(cssVarsDefinition, importer), expected(cssVarsExpected, importerExpected));
-    assertThat(cssNames).containsExactly("fooStylesBar", 1, "active", 1);
+    assertThat(cssNames).containsExactly("fooStylesBar", "active");
   }
 
   @Test

test/com/google/javascript/jscomp/integration/IntegrationTest.java

@@ -1239,7 +1239,7 @@ public void testReplaceCssNames() {
             + "}",
         "var COMPILED = true;\n" + "function getCss() {\n" + "  return 'bar';" + "}");
 
-    assertThat(lastCompiler.getResult().cssNames).containsExactly("foo", 1);
+    assertThat(lastCompiler.getResult().cssNames).containsExactly("foo");
   }
 
   @Test