Add BROWSER_FEATURESET_YEAR 2023

PiperOrigin-RevId: 504951035

Author: Closure Team

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

@@ -157,14 +157,16 @@ private class BrowserFeaturesetYear implements Serializable {
 
     BrowserFeaturesetYear(int year) {
       checkState(
-          year == 2012 || (year >= 2018 && year <= 2022),
-          "Illegal browser_featureset_year=%s. We support values 2012, or 2018..2022 only",
+          year == 2012 || (year >= 2018 && year <= 2023),
+          "Illegal browser_featureset_year=%s. We support values 2012, or 2018..2023 only",
           year);
       this.year = year;
     }
 
     void setDependentValuesFromYear() {
-      if (year == 2022) {
+      if (year == 2023) {
+        setOutputFeatureSet(FeatureSet.BROWSER_2023);
+      } else if (year == 2022) {
         setOutputFeatureSet(FeatureSet.BROWSER_2022);
       } else if (year == 2021) {
         setOutputFeatureSet(FeatureSet.BROWSER_2021);
@@ -214,8 +216,7 @@ public void setTypedAstOutputFile(@Nullable Path file) {
     this.typedAstOutputFile = file;
   }
 
-  @Nullable
-  Path getTypedAstOutputFile() {
+  @Nullable Path getTypedAstOutputFile() {
     return this.typedAstOutputFile;
   }
 
@@ -702,7 +703,6 @@ public boolean shouldRunReplaceMessagesForChrome() {
     }
   }
 
-
   /** A CodingConvention to use during the compile. */
   private CodingConvention codingConvention;
 
@@ -1092,7 +1092,7 @@ public boolean shouldProtectHiddenSideEffects() {
    * or side-effected. Gets that can be proven to be pure may still be considered as such.
    *
    * <p>Recall that object-spread is capable of triggering getters. Since the syntax doesn't
-   * explicitly specifiy a property, it is essentailly impossible to prove it has no side-effects
+   * explicitly specify a property, it is essentailly impossible to prove it has no side-effects
    * without this assumption.
    */
   private boolean assumeGettersArePure = true;
@@ -1800,7 +1800,7 @@ public void setLanguageOut(LanguageMode languageOut) {
    * Sets the features that allowed to appear in the output. Any feature in the input that is not in
    * this output must be transpiled away.
    *
-   * <p>Note: this is an package private API since not every FeatureSet value can be properly output
+   * <p>Note: this is a package private API since not every FeatureSet value can be properly output
    * by the compiler without crashing. Both the `setBrowserFeaturesetYear` and `setLanguageOut` APIs
    * are supported alternatives.
    */
@@ -2275,7 +2275,6 @@ public void setExportTestFunctions(boolean exportTestFunctions) {
     this.exportTestFunctions = exportTestFunctions;
   }
 
-
   public void setSyntheticBlockStartMarker(String syntheticBlockStartMarker) {
     this.syntheticBlockStartMarker = syntheticBlockStartMarker;
   }

src/com/google/javascript/jscomp/parsing/parser/FeatureSet.java

@@ -108,16 +108,20 @@ public final class FeatureSet implements Serializable {
       ES2020_MODULES.without(
           // https://kangax.github.io/compat-table/es2016plus/
           // Regexp lookbehind is missing in Safari 14.
-          // IMPORTANT: There is special casing for this feature and the ones excluded for
-          // BROWSER_2020 above in RewritePolyfills.
-          // If future Browser FeatureSet Year definitions have to remove any other features, then
-          // we need to change the way that is done to avoid incorrect inclusion of polyfills.
           Feature.REGEXP_LOOKBEHIND);
 
   public static final FeatureSet BROWSER_2022 =
       ES2021_MODULES.without(
           // https://kangax.github.io/compat-table/es2016plus/
           // Regexp lookbehind is still missing in Safari 15.
+          Feature.REGEXP_LOOKBEHIND);
+
+  public static final FeatureSet BROWSER_2023 =
+      ES2021_MODULES.without(
+          // https://kangax.github.io/compat-table/es2016plus/
+          // Regexp lookbehind is still missing in Safari 16.2! It's in Safari TP though so
+          // 2024 shouldn't need this awkward hack. We can't bump up to ES2022 here because
+          // Safari 16.2 doesn't support class static blocks.
           // IMPORTANT: There is special casing for this feature and the ones excluded for
           // BROWSER_2020 above in RewritePolyfills.
           // If future Browser FeatureSet Year definitions have to remove any other features, then

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

@@ -54,6 +54,9 @@ public void testBrowserFeaturesetYearOptionSetsLanguageOut() {
 
     options.setBrowserFeaturesetYear(2022);
     assertThat(options.getOutputFeatureSet()).isEqualTo(FeatureSet.BROWSER_2022);
+
+    options.setBrowserFeaturesetYear(2023);
+    assertThat(options.getOutputFeatureSet()).isEqualTo(FeatureSet.BROWSER_2023);
   }
 
   @Test