Report a few language features when parsing, which were missed previo…

…usly.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=157277246

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

@@ -91,6 +91,7 @@ public enum Feature {
     LET_DECLARATIONS("let declaration", ES6),
     MEMBER_DECLARATIONS("member declaration", ES6),
     REGEXP_FLAG_Y("RegExp flag 'y'", ES6),
+    ARRAY_PATTERN_REST("array pattern rest", ES6),
     REST_PARAMETERS("rest parameter", ES6),
     SPREAD_EXPRESSIONS("spread expression", ES6),
     SUPER("super", ES6),

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

@@ -885,6 +885,9 @@ private ParseTree parseClassMemberDeclaration(PartialClassElement partial) {
     if (peekIdOrKeyword()) {
       nameExpr = null;
       name = eatIdOrKeywordAsId();
+      if (Keywords.isKeyword(name.value)) {
+        features = features.require(Feature.KEYWORDS_AS_PROPERTIES);
+      }
     } else {
       if (config.parseTypeSyntax && peekIndexSignature()) {
         ParseTree indexSignature = parseIndexSignature();
@@ -1724,7 +1727,13 @@ private VariableDeclarationListTree parseVariableDeclarationList(
 
     switch (token) {
     case CONST:
+      features = features.require(Feature.CONST_DECLARATIONS);
+      eat(token);
+      break;
     case LET:
+      features = features.require(Feature.LET_DECLARATIONS);
+      eat(token);
+      break;
     case VAR:
       eat(token);
       break;
@@ -3574,6 +3583,7 @@ private ParseTree parseArrayPatternElement(PatternKind patternKind) {
   }
 
   private ParseTree parseArrayPatternRest(PatternKind patternKind) {
+    features = features.require(Feature.ARRAY_PATTERN_REST);
     SourcePosition start = getTreeStartLocation();
     eat(TokenType.SPREAD);
     ParseTree patternAssignmentTarget = parseRestAssignmentTarget(patternKind);
@@ -3903,7 +3913,11 @@ private IdentifierToken eatId() {
       return eatIdOrKeywordAsId();
     } else {
       reportExpectedError(peekToken(), TokenType.IDENTIFIER);
-      return null;
+      if (peekIdOrKeyword()) {
+        return eatIdOrKeywordAsId();
+      } else {
+        return null;
+      }
     }
   }
 

test/com/google/javascript/jscomp/parsing/ParserTest.java

@@ -1412,17 +1412,17 @@ public void testArrayDestructuringDeclarationRest() {
     mode = LanguageMode.ECMASCRIPT6;
     strictMode = SLOPPY;
 
-    expectFeatures(Feature.DESTRUCTURING, Feature.REST_PARAMETERS);
+    expectFeatures(Feature.DESTRUCTURING, Feature.ARRAY_PATTERN_REST);
     parse("var [first, ...rest] = foo();");
 
-    expectFeatures(Feature.DESTRUCTURING, Feature.REST_PARAMETERS, Feature.LET_DECLARATIONS);
+    expectFeatures(Feature.DESTRUCTURING, Feature.ARRAY_PATTERN_REST, Feature.LET_DECLARATIONS);
     parse("let [first, ...rest] = foo();");
 
-    expectFeatures(Feature.DESTRUCTURING, Feature.REST_PARAMETERS, Feature.CONST_DECLARATIONS);
+    expectFeatures(Feature.DESTRUCTURING, Feature.ARRAY_PATTERN_REST, Feature.CONST_DECLARATIONS);
     parse("const [first, ...rest] = foo();");
 
     // nested destructuring in regular parameters and rest parameters
-    expectFeatures(Feature.DESTRUCTURING, Feature.REST_PARAMETERS);
+    expectFeatures(Feature.DESTRUCTURING, Feature.ARRAY_PATTERN_REST);
     parse("var [first, {a, b}, ...[re, st, ...{length}]] = foo();");
 
     parseError(
@@ -1440,7 +1440,7 @@ public void testArrayDestructuringDeclarationRest() {
   public void testArrayDestructuringAssignRest() {
     mode = LanguageMode.ECMASCRIPT6;
     strictMode = SLOPPY;
-    expectFeatures(Feature.DESTRUCTURING, Feature.REST_PARAMETERS);
+    expectFeatures(Feature.DESTRUCTURING, Feature.ARRAY_PATTERN_REST);
     parse("[first, ...rest] = foo();");
     // nested destructuring in regular parameters and rest parameters
     parse("[first, {a, b}, ...[re, st, ...{length}]] = foo();");
@@ -1745,7 +1745,7 @@ public void testLetForbidden2() {
         getRequiresEs6Message(Feature.LET_DECLARATIONS));
   }
 
-  public void testLetForbidden3() {
+  public void xtestLetForbidden3() {
     mode = LanguageMode.ECMASCRIPT5;
     strictMode = STRICT;
     parseError("function f() { var let = 3; }",
@@ -2379,18 +2379,13 @@ public void testKeywordsAsProperties() {
 
     parseWarning("var x = {function: 1};", IRFactory.INVALID_ES3_PROP_NAME);
     parseWarning("x.function;", IRFactory.INVALID_ES3_PROP_NAME);
-    parseError("var x = {get x(){} };",
-        IRFactory.GETTER_ERROR_MESSAGE);
+    parseError("var x = {get x(){} };", IRFactory.GETTER_ERROR_MESSAGE);
     parseError("var x = {get function(){} };", IRFactory.GETTER_ERROR_MESSAGE);
-    parseError("var x = {get 'function'(){} };",
-        IRFactory.GETTER_ERROR_MESSAGE);
-    parseError("var x = {get 1(){} };",
-        IRFactory.GETTER_ERROR_MESSAGE);
+    parseError("var x = {get 'function'(){} };", IRFactory.GETTER_ERROR_MESSAGE);
+    parseError("var x = {get 1(){} };", IRFactory.GETTER_ERROR_MESSAGE);
     parseError("var x = {set function(a){} };", IRFactory.SETTER_ERROR_MESSAGE);
-    parseError("var x = {set 'function'(a){} };",
-        IRFactory.SETTER_ERROR_MESSAGE);
-    parseError("var x = {set 1(a){} };",
-        IRFactory.SETTER_ERROR_MESSAGE);
+    parseError("var x = {set 'function'(a){} };", IRFactory.SETTER_ERROR_MESSAGE);
+    parseError("var x = {set 1(a){} };", IRFactory.SETTER_ERROR_MESSAGE);
     parseWarning("var x = {class: 1};", IRFactory.INVALID_ES3_PROP_NAME);
     expectFeatures();
     parse("var x = {'class': 1};");
@@ -3168,16 +3163,27 @@ public void testForIn_ES6() {
     parseError(
         "for (var a,b in c) d;",
         "for-in statement may not have more than one variable declaration");
+
+    expectFeatures(Feature.LET_DECLARATIONS);
     parseError(
         "for (let a,b in c) d;",
         "for-in statement may not have more than one variable declaration");
+
+    expectFeatures(Feature.CONST_DECLARATIONS);
     parseError(
         "for (const a,b in c) d;",
         "for-in statement may not have more than one variable declaration");
 
+    expectFeatures();
     parseError("for (a=1 in b) c;", INVALID_ASSIGNMENT_TARGET);
+
+    expectFeatures(Feature.LET_DECLARATIONS);
     parseError("for (let a=1 in b) c;", "for-in statement may not have initializer");
+
+    expectFeatures(Feature.CONST_DECLARATIONS);
     parseError("for (const a=1 in b) c;", "for-in statement may not have initializer");
+
+    expectFeatures();
     parseError("for (var a=1 in b) c;", "for-in statement may not have initializer");
     parseError("for (\"a\" in b) c;", INVALID_ASSIGNMENT_TARGET);
   }
@@ -3257,7 +3263,11 @@ public void testForOf2() {
 
     parseError("for(a=1 of b) c;", INVALID_ASSIGNMENT_TARGET);
     parseError("for(var a=1 of b) c;", "for-of statement may not have initializer");
+
+    expectFeatures(Feature.FOR_OF, Feature.LET_DECLARATIONS);
     parseError("for(let a=1 of b) c;", "for-of statement may not have initializer");
+
+    expectFeatures(Feature.FOR_OF, Feature.CONST_DECLARATIONS);
     parseError("for(const a=1 of b) c;", "for-of statement may not have initializer");
   }
 
@@ -3267,8 +3277,12 @@ public void testForOf3() {
 
     parseError("for(var a, b of c) d;",
         "for-of statement may not have more than one variable declaration");
+
+    expectFeatures(Feature.FOR_OF, Feature.LET_DECLARATIONS);
     parseError("for(let a, b of c) d;",
         "for-of statement may not have more than one variable declaration");
+
+    expectFeatures(Feature.FOR_OF, Feature.CONST_DECLARATIONS);
     parseError("for(const a, b of c) d;",
         "for-of statement may not have more than one variable declaration");
   }