JavaScript: Fix parsing of asynchronous generator methods.

Author: Max Schaefer

change-notes/1.23/extractor-javascript.md

@@ -0,0 +1,7 @@
+[[ condition: enterprise-only ]]
+
+# Improvements to JavaScript analysis
+
+## Changes to code extraction
+
+* Asynchronous generator methods are now parsed correctly and no longer cause a spurious syntax error.

javascript/extractor/src/com/semmle/jcorn/Parser.java

@@ -1944,6 +1944,7 @@ protected Property parseProperty(
     this.parsePropertyName(pi);
     if (!isPattern && this.options.ecmaVersion() >= 8 && !isGenerator && this.isAsyncProp(pi)) {
       pi.isAsync = true;
+      pi.isGenerator = this.eat(TokenType.star);
       this.parsePropertyName(pi);
     } else {
       pi.isAsync = false;
@@ -1964,6 +1965,7 @@ private boolean isAsyncProp(PropertyInfo pi) {
             || this.type == TokenType.num
             || this.type == TokenType.string
             || this.type == TokenType.bracketL
+            || this.type == TokenType.star
             || this.type.keyword != null)
         && !this.canInsertSemicolon();
   }
@@ -3166,6 +3168,7 @@ protected MemberDefinition<?> parseClassMember(boolean hadConstructor) {
     }
     if (this.options.ecmaVersion() >= 8 && !isGenerator && this.isAsyncProp(pi)) {
       pi.isAsync = true;
+      pi.isGenerator = this.eat(TokenType.star);
       this.parsePropertyName(pi);
     }
     return parseClassPropertyBody(pi, hadConstructor, isStatic);

javascript/extractor/src/com/semmle/js/extractor/Main.java

@@ -37,7 +37,7 @@ public class Main {
    * A version identifier that should be updated every time the extractor changes in such a way that
    * it may produce different tuples for the same file under the same {@link ExtractorConfig}.
    */
-  public static final String EXTRACTOR_VERSION = "2019-07-25";
+  public static final String EXTRACTOR_VERSION = "2019-09-02";
 
   public static final Pattern NEWLINE = Pattern.compile("\n");
 

javascript/extractor/tests/es2018/input/asyncIter.js

@@ -0,0 +1,11 @@
+async function* asyncFn() {}
+
+class C {
+  async *asyncMeth() {}
+  async *[Symbol.asyncIterator]() {}
+}
+
+var o = {
+  async *asyncMeth() {},
+  async *[Symbol.asyncIterator]() {}
+}