From 0c66c4780ab69d94a9b9b62f146c8b827e5018a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hu=C3=A1ng=20J=C3=B9nli=C3=A0ng?= <jlhwung@gmail.com>
Date: Mon, 30 Dec 2019 21:09:26 -0500
Subject: [PATCH] fix: add SCOPE_ASYNC to program scope when topLevelAwait is
 enable

---
 packages/babel-parser/src/parser/expression.js        | 11 +++++++++--
 packages/babel-parser/src/parser/index.js             |  8 ++++++--
 .../top-level-await/inside-class-property/input.js    |  3 +++
 .../inside-class-property/options.json                |  8 ++++++++
 .../module-namespace/top-level-await/input.ts         |  3 +++
 .../module-namespace/top-level-await/options.json     |  8 ++++++++
 6 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/input.js
 create mode 100644 packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/options.json
 create mode 100644 packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/input.ts
 create mode 100644 packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/options.json

diff --git a/packages/babel-parser/src/parser/expression.js b/packages/babel-parser/src/parser/expression.js
index 1ef6fcf82f96..b4f1d89c06c5 100644
--- a/packages/babel-parser/src/parser/expression.js
+++ b/packages/babel-parser/src/parser/expression.js
@@ -39,6 +39,7 @@ import {
   SCOPE_DIRECT_SUPER,
   SCOPE_SUPER,
   SCOPE_PROGRAM,
+  SCOPE_ASYNC,
 } from "../util/scopeflags";
 
 export default class ExpressionParser extends LValParser {
@@ -96,7 +97,11 @@ export default class ExpressionParser extends LValParser {
 
   // Convenience method to parse an Expression only
   getExpression(): N.Expression {
-    this.scope.enter(SCOPE_PROGRAM);
+    let scopeFlags = SCOPE_PROGRAM;
+    if (this.hasPlugin("topLevelAwait") && this.inModule) {
+      scopeFlags |= SCOPE_ASYNC;
+    }
+    this.scope.enter(scopeFlags);
     this.nextToken();
     const expr = this.parseExpression();
     if (!this.match(tt.eof)) {
@@ -2186,7 +2191,9 @@ export default class ExpressionParser extends LValParser {
   isAwaitAllowed(): boolean {
     if (this.scope.inFunction) return this.scope.inAsync;
     if (this.options.allowAwaitOutsideFunction) return true;
-    if (this.hasPlugin("topLevelAwait")) return this.inModule;
+    if (this.hasPlugin("topLevelAwait")) {
+      return this.inModule && this.scope.inAsync;
+    }
     return false;
   }
 
diff --git a/packages/babel-parser/src/parser/index.js b/packages/babel-parser/src/parser/index.js
index 2c96336f1c13..681de32d0560 100644
--- a/packages/babel-parser/src/parser/index.js
+++ b/packages/babel-parser/src/parser/index.js
@@ -5,7 +5,7 @@ import type { File, JSXOpeningElement } from "../types";
 import type { PluginList } from "../plugin-utils";
 import { getOptions } from "../options";
 import StatementParser from "./statement";
-import { SCOPE_PROGRAM } from "../util/scopeflags";
+import { SCOPE_ASYNC, SCOPE_PROGRAM } from "../util/scopeflags";
 import ScopeHandler from "../util/scope";
 
 export type PluginsMap = Map<string, { [string]: any }>;
@@ -35,7 +35,11 @@ export default class Parser extends StatementParser {
   }
 
   parse(): File {
-    this.scope.enter(SCOPE_PROGRAM);
+    let scopeFlags = SCOPE_PROGRAM;
+    if (this.hasPlugin("topLevelAwait") && this.inModule) {
+      scopeFlags |= SCOPE_ASYNC;
+    }
+    this.scope.enter(scopeFlags);
     const file = this.startNode();
     const program = this.startNode();
     this.nextToken();
diff --git a/packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/input.js b/packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/input.js
new file mode 100644
index 000000000000..d17e57ee1081
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/input.js
@@ -0,0 +1,3 @@
+export class C {
+  p = await 0;
+}
diff --git a/packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/options.json b/packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/options.json
new file mode 100644
index 000000000000..0688c012b357
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/experimental/top-level-await/inside-class-property/options.json
@@ -0,0 +1,8 @@
+{
+  "plugins": [
+    "topLevelAwait",
+    "classProperties"
+  ],
+  "sourceType": "module",
+  "throws": "Unexpected token, expected \";\" (2:12)"
+}
\ No newline at end of file
diff --git a/packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/input.ts b/packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/input.ts
new file mode 100644
index 000000000000..9302309c5933
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/input.ts
@@ -0,0 +1,3 @@
+namespace N {
+    const x = await 42;
+}
diff --git a/packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/options.json b/packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/options.json
new file mode 100644
index 000000000000..ba579946562a
--- /dev/null
+++ b/packages/babel-parser/test/fixtures/typescript/module-namespace/top-level-await/options.json
@@ -0,0 +1,8 @@
+{
+  "sourceType": "module",
+  "plugins": [
+    "typescript",
+    "topLevelAwait"
+  ],
+  "throws": "Unexpected token, expected \";\" (2:20)"
+}
\ No newline at end of file