Merge pull request #17 from zenparsing/master

Parse for-await statements when asyncGenerators plugin is active

src/parser/statement.js

@@ -224,9 +224,18 @@ pp.parseDoStatement = function (node) {
 pp.parseForStatement = function (node) {
   this.next();
   this.state.labels.push(loopLabel);
+
+  let forAwait = false;
+  if (this.hasPlugin("asyncGenerators") && this.state.inAsync && this.isContextual("await")) {
+      forAwait = true;
+      this.next();
+  }
   this.expect(tt.parenL);
 
   if (this.match(tt.semi)) {
+    if (forAwait) {
+      this.unexpected();
+    }
     return this.parseFor(node, null);
   }
 
@@ -238,10 +247,12 @@ pp.parseForStatement = function (node) {
 
     if (this.match(tt._in) || this.isContextual("of")) {
       if (init.declarations.length === 1 && !init.declarations[0].init) {
-        return this.parseForIn(node, init);
+        return this.parseForIn(node, init, forAwait);
       }
     }
-
+    if (forAwait) {
+      this.unexpected();
+    }
     return this.parseFor(node, init);
   }
 
@@ -250,10 +261,13 @@ pp.parseForStatement = function (node) {
   if (this.match(tt._in) || this.isContextual("of")) {
     this.toAssignable(init);
     this.checkLVal(init);
-    return this.parseForIn(node, init);
+    return this.parseForIn(node, init, forAwait);
   } else if (refShorthandDefaultPos.start) {
     this.unexpected(refShorthandDefaultPos.start);
   }
+  if (forAwait) {
+    this.unexpected();
+  }
   return this.parseFor(node, init);
 };
 
@@ -508,9 +522,15 @@ pp.parseFor = function (node, init) {
 // Parse a `for`/`in` and `for`/`of` loop, which are almost
 // same from parser's perspective.
 
-pp.parseForIn = function (node, init) {
-  let type = this.match(tt._in) ? "ForInStatement" : "ForOfStatement";
-  this.next();
+pp.parseForIn = function (node, init, forAwait) {
+  let type;
+  if (forAwait) {
+    this.eatContextual("of");
+    type = "ForAwaitStatement";
+  } else {
+    type = this.match(tt._in) ? "ForInStatement" : "ForOfStatement";
+    this.next();
+  }
   node.left = init;
   node.right = this.parseExpression();
   this.expect(tt.parenR);

test/fixtures/experimental/async-generators/for-await-async-context/actual.js

@@ -0,0 +1,3 @@
+function f() {
+  for await (let x of y);
+}

test/fixtures/experimental/async-generators/for-await-async-context/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (2:6)"
+}

test/fixtures/experimental/async-generators/for-await-no-in/actual.js

@@ -0,0 +1,3 @@
+async function f() {
+  for await (let x in y);
+}

test/fixtures/experimental/async-generators/for-await-no-in/expected.json

@@ -0,0 +1,184 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 48,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 3,
+      "column": 1
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 48,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 3,
+        "column": 1
+      }
+    },
+    "sourceType": "script",
+    "body": [
+      {
+        "type": "FunctionDeclaration",
+        "start": 0,
+        "end": 48,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 3,
+            "column": 1
+          }
+        },
+        "id": {
+          "type": "Identifier",
+          "start": 15,
+          "end": 16,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 15
+            },
+            "end": {
+              "line": 1,
+              "column": 16
+            }
+          },
+          "name": "f"
+        },
+        "generator": false,
+        "expression": false,
+        "async": true,
+        "params": [],
+        "body": {
+          "type": "BlockStatement",
+          "start": 19,
+          "end": 48,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 19
+            },
+            "end": {
+              "line": 3,
+              "column": 1
+            }
+          },
+          "body": [
+            {
+              "type": "ForAwaitStatement",
+              "start": 23,
+              "end": 46,
+              "loc": {
+                "start": {
+                  "line": 2,
+                  "column": 2
+                },
+                "end": {
+                  "line": 2,
+                  "column": 25
+                }
+              },
+              "await": true,
+              "left": {
+                "type": "VariableDeclaration",
+                "start": 34,
+                "end": 39,
+                "loc": {
+                  "start": {
+                    "line": 2,
+                    "column": 13
+                  },
+                  "end": {
+                    "line": 2,
+                    "column": 18
+                  }
+                },
+                "declarations": [
+                  {
+                    "type": "VariableDeclarator",
+                    "start": 38,
+                    "end": 39,
+                    "loc": {
+                      "start": {
+                        "line": 2,
+                        "column": 17
+                      },
+                      "end": {
+                        "line": 2,
+                        "column": 18
+                      }
+                    },
+                    "id": {
+                      "type": "Identifier",
+                      "start": 38,
+                      "end": 39,
+                      "loc": {
+                        "start": {
+                          "line": 2,
+                          "column": 17
+                        },
+                        "end": {
+                          "line": 2,
+                          "column": 18
+                        }
+                      },
+                      "name": "x"
+                    },
+                    "init": null
+                  }
+                ],
+                "kind": "let"
+              },
+              "right": {
+                "type": "Identifier",
+                "start": 43,
+                "end": 44,
+                "loc": {
+                  "start": {
+                    "line": 2,
+                    "column": 22
+                  },
+                  "end": {
+                    "line": 2,
+                    "column": 23
+                  }
+                },
+                "name": "y"
+              },
+              "body": {
+                "type": "EmptyStatement",
+                "start": 45,
+                "end": 46,
+                "loc": {
+                  "start": {
+                    "line": 2,
+                    "column": 24
+                  },
+                  "end": {
+                    "line": 2,
+                    "column": 25
+                  }
+                }
+              }
+            }
+          ],
+          "directives": []
+        }
+      }
+    ],
+    "directives": []
+  }
+}

test/fixtures/experimental/async-generators/for-await-no-in/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (2:19)"
+}

test/fixtures/experimental/async-generators/for-await-no-semi-1/actual.js

@@ -0,0 +1,3 @@
+async function f() {
+  for await (;false;);
+}

test/fixtures/experimental/async-generators/for-await-no-semi-1/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (2:13)"
+}

test/fixtures/experimental/async-generators/for-await-no-semi-2/actual.js

@@ -0,0 +1,3 @@
+async function f() {
+  for await (let i = 0;false;);
+}

test/fixtures/experimental/async-generators/for-await-no-semi-2/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (2:22)"
+}

test/fixtures/experimental/async-generators/for-await-no-semi-3/actual.js

@@ -0,0 +1,3 @@
+async function f() {
+  for await (x = 0;false;);
+}

test/fixtures/experimental/async-generators/for-await-no-semi-3/options.json

@@ -0,0 +1,3 @@
+{
+  "throws": "Unexpected token (2:18)"
+}

test/fixtures/experimental/async-generators/for-await/actual.js

@@ -0,0 +1,3 @@
+async function f() {
+  for await (let x of y);
+}