Create individual Features for ARRAY_DESTRUCTURING and OBJECT_DESTRUC…

…TURING

This will it easier to inject runtime libraries only needed for array
destructuring in Es6InjectRuntimeLibraries

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=214699989

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

@@ -1129,7 +1129,7 @@ private void validateGetPropGetElemInLHS(Token contextType, Node n) {
   }
 
   private void validateArrayPattern(Token type, Node n) {
-    validateFeature(Feature.DESTRUCTURING, n);
+    validateFeature(Feature.ARRAY_DESTRUCTURING, n);
     validateNodeType(Token.ARRAY_PATTERN, n);
     for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
       switch (c.getToken()) {
@@ -1149,7 +1149,7 @@ private void validateArrayPattern(Token type, Node n) {
   }
 
   private void validateObjectPattern(Token type, Node n) {
-    validateFeature(Feature.DESTRUCTURING, n);
+    validateFeature(Feature.OBJECT_DESTRUCTURING, n);
     validateNodeType(Token.OBJECT_PATTERN, n);
     for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
       switch (c.getToken()) {

src/com/google/javascript/jscomp/Es6RewriteDestructuring.java

@@ -83,7 +83,10 @@ private Es6RewriteDestructuring(Builder builder) {
       case REWRITE_ALL_OBJECT_PATTERNS:
         this.featuresToTriggerRunningPass =
             FeatureSet.BARE_MINIMUM.with(
-                Feature.DEFAULT_PARAMETERS, Feature.DESTRUCTURING, Feature.ARRAY_PATTERN_REST);
+                Feature.DEFAULT_PARAMETERS,
+                Feature.ARRAY_DESTRUCTURING,
+                Feature.ARRAY_PATTERN_REST,
+                Feature.OBJECT_DESTRUCTURING);
 
         // If OBJECT_PATTERN_REST were to be present in featuresToTriggerRunningPass and not the
         // input language featureSet (such as ES6=>ES5) the pass would be skipped.

src/com/google/javascript/jscomp/Es6SplitVariableDeclarations.java

@@ -42,7 +42,7 @@ public final class Es6SplitVariableDeclarations extends
     NodeTraversal.AbstractPostOrderCallback implements HotSwapCompilerPass {
   private final AbstractCompiler compiler;
   private static final FeatureSet transpiledFeatures =
-      FeatureSet.BARE_MINIMUM.with(Feature.DESTRUCTURING);
+      FeatureSet.BARE_MINIMUM.with(Feature.ARRAY_DESTRUCTURING, Feature.OBJECT_DESTRUCTURING);
 
   public Es6SplitVariableDeclarations(AbstractCompiler compiler) {
     this.compiler = compiler;

src/com/google/javascript/jscomp/parsing/IRFactory.java

@@ -1026,7 +1026,7 @@ Node processArrayLiteral(ArrayLiteralExpressionTree tree) {
     }
 
     Node processArrayPattern(ArrayPatternTree tree) {
-      maybeWarnForFeature(tree, Feature.DESTRUCTURING);
+      maybeWarnForFeature(tree, Feature.ARRAY_DESTRUCTURING);
 
       Node node = newNode(Token.ARRAY_PATTERN);
       for (ParseTree child : tree.elements) {
@@ -1043,7 +1043,7 @@ Node processArrayPattern(ArrayPatternTree tree) {
     }
 
     Node processObjectPattern(ObjectPatternTree tree) {
-      maybeWarnForFeature(tree, Feature.DESTRUCTURING);
+      maybeWarnForFeature(tree, Feature.OBJECT_DESTRUCTURING);
 
       Node node = newNode(Token.OBJECT_PATTERN);
       for (ParseTree child : tree.fields) {
@@ -1527,8 +1527,10 @@ Node processRestParameter(RestParameterTree tree) {
       maybeWarnForFeature(tree, Feature.REST_PARAMETERS);
 
       Node assignmentTarget = transformNodeWithInlineJsDoc(tree.assignmentTarget);
-      if (assignmentTarget.isDestructuringPattern()) {
-        maybeWarnForFeature(tree.assignmentTarget, Feature.DESTRUCTURING);
+      if (assignmentTarget.isObjectPattern()) {
+        maybeWarnForFeature(tree.assignmentTarget, Feature.OBJECT_DESTRUCTURING);
+      } else if (assignmentTarget.isArrayPattern()) {
+        maybeWarnForFeature(tree.assignmentTarget, Feature.ARRAY_DESTRUCTURING);
       }
       return newNode(Token.REST, assignmentTarget);
     }

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

@@ -81,7 +81,8 @@ public final class FeatureSet implements Serializable {
           .without(Feature.CLASS_EXTENDS)
           .without(Feature.CLASS_GETTER_SETTER)
           .without(Feature.DEFAULT_PARAMETERS)
-          .without(Feature.DESTRUCTURING)
+          .without(Feature.ARRAY_DESTRUCTURING)
+          .without(Feature.OBJECT_DESTRUCTURING)
           .without(Feature.MODULES)
           .without(Feature.NEW_TARGET);
 
@@ -127,7 +128,8 @@ public enum Feature {
     COMPUTED_PROPERTIES("computed property", LangVersion.ES6),
     CONST_DECLARATIONS("const declaration", LangVersion.ES6),
     DEFAULT_PARAMETERS("default parameter", LangVersion.ES6),
-    DESTRUCTURING("destructuring", LangVersion.ES6),
+    ARRAY_DESTRUCTURING("array destructuring", LangVersion.ES6),
+    OBJECT_DESTRUCTURING("object destructuring", LangVersion.ES6),
     EXTENDED_OBJECT_LITERALS("extended object literal", LangVersion.ES6),
     FOR_OF("for-of loop", LangVersion.ES6),
     GENERATORS("generator", LangVersion.ES6),

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

@@ -492,13 +492,19 @@ public void testFeatureValidation_defaultParameters() {
   }
 
   @Test
-  public void testFeatureValidation_destructuring() {
-    testFeatureValidation("var x, {a, b} = obj;", Feature.DESTRUCTURING);
-    testFeatureValidation("var x, [a, b] = arr;", Feature.DESTRUCTURING);
-    testFeatureValidation("(x = 0, {a, b} = obj);", Feature.DESTRUCTURING);
-    testFeatureValidation("x = 0, [a, b] = obj;", Feature.DESTRUCTURING);
-    testFeatureValidation("for ({a, b} of c) {}", Feature.DESTRUCTURING);
-    testFeatureValidation("for ([a, b] of c) {}", Feature.DESTRUCTURING);
+  public void testFeatureValidation_arrayDestructuring() {
+    testFeatureValidation("var x, [a, b] = arr;", Feature.ARRAY_DESTRUCTURING);
+    testFeatureValidation("x = 0, [a, b] = obj;", Feature.ARRAY_DESTRUCTURING);
+    testFeatureValidation("for ([a, b] of c) {}", Feature.ARRAY_DESTRUCTURING);
+    testFeatureValidation("function f([a, b]) {}", Feature.ARRAY_DESTRUCTURING);
+  }
+
+  @Test
+  public void testFeatureValidation_objectDestructuring() {
+    testFeatureValidation("var x, {a, b} = obj;", Feature.OBJECT_DESTRUCTURING);
+    testFeatureValidation("(x = 0, {a, b} = obj);", Feature.OBJECT_DESTRUCTURING);
+    testFeatureValidation("for ({a, b} of c) {}", Feature.OBJECT_DESTRUCTURING);
+    testFeatureValidation("function f({a, b}) {}", Feature.OBJECT_DESTRUCTURING);
   }
 
   @Test