Added checks for getters and setters in class definitions.

-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=70416871

Author: blickly

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

@@ -367,8 +367,13 @@ private void validateClassMembers(Node n) {
   }
 
   private void validateClassMember(Node n) {
-    validateNodeType(Token.MEMBER_DEF, n);
-    validateChildCount(n, Token.arity(Token.MEMBER_DEF));
+    if (n.getType() != Token.MEMBER_DEF
+        && n.getType() != Token.GETTER_DEF
+        && n.getType() != Token.SETTER_DEF) {
+      violation("Class contained member which was not a MEMBER_DEF, GETTER_DEF, or SETTER_DEF",
+          n);
+    }
+    validateChildCount(n, Token.arity(n.getType()));
     validateFunctionExpression(n.getFirstChild());
   }
 

src/com/google/javascript/jscomp/Es6ToEs3Converter.java

@@ -119,6 +119,9 @@ public boolean shouldTraverse(NodeTraversal t, Node n, Node parent) {
         // Need to check for super references before they get rewritten.
         checkClassSuperReferences(n);
         break;
+      case Token.CLASS_MEMBERS:
+        checkMemberDefs(n);
+        break;
       case Token.ARRAY_COMP:
       case Token.ARRAY_PATTERN:
       case Token.OBJECT_PATTERN:
@@ -238,6 +241,14 @@ private void checkClassReassignment(Node clazz) {
     NodeTraversal.traverse(compiler, enclosingFunction, checkAssigns);
   }
 
+  public void checkMemberDefs(Node members) {
+    for (Node member : members.children()) {
+      if (member.isGetterDef() || member.isSetterDef()) {
+        cannotConvert(member, "Cannot convert getters or setters in class definitions.");
+      }
+    }
+  }
+
   private void visitSuper(Node node, Node parent) {
     Node enclosing = parent;
     Node potentialCallee = node;

test/com/google/javascript/jscomp/Es6ToEs3ConverterTest.java

@@ -783,6 +783,12 @@ public void testInvalidClassUse() {
     ), null, null, TypeCheck.CONFLICTING_SHAPE_TYPE);
   }
 
+  public void testClassGetterSetter() {
+    test("class C { get value() {} }", null, Es6ToEs3Converter.CANNOT_CONVERT);
+
+    test("class C { set value(v) {} }", null, Es6ToEs3Converter.CANNOT_CONVERT);
+  }
+
   public void testArrowFunction() {
     test("var f = x => { return x+1; };",
         "var f = function(x) { return x+1; };");