Expose wether a module has TLA or not as .extra.async

packages/babel-core/test/fixtures/parse/output.json

@@ -316,7 +316,10 @@
         }
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   },
   "comments": []
 }

packages/babel-parser/src/parser/expression.ts

@@ -606,7 +606,7 @@ export default abstract class ExpressionParser extends LValParser {
     const startLoc = this.state.startLoc;
     const isAwait = this.isContextual(tt._await);
 
-    if (isAwait && this.isAwaitAllowed()) {
+    if (isAwait && this.recordAwaitIfAllowed()) {
       this.next();
       const expr = this.parseAwait(startLoc);
       if (!sawUnary) this.checkExponentialAfterUnary(expr);
@@ -2869,12 +2869,18 @@ export default abstract class ExpressionParser extends LValParser {
     }
   }
 
-  isAwaitAllowed(): boolean {
-    if (this.prodParam.hasAwait) return true;
-    if (this.options.allowAwaitOutsideFunction && !this.scope.inFunction) {
-      return true;
+  // Returns wether `await` is allowed or not in this context, and if it is
+  // keeps track of it to determine whether a module uses top-level await.
+  recordAwaitIfAllowed(): boolean {
+    const isAwaitAllowed =
+      this.prodParam.hasAwait ||
+      (this.options.allowAwaitOutsideFunction && !this.scope.inFunction);
+
+    if (isAwaitAllowed && !this.scope.inFunction) {
+      this.state.hasTopLevelAwait = true;
     }
-    return false;
+
+    return isAwaitAllowed;
   }
 
   // Parses await expression inside async function.

packages/babel-parser/src/parser/statement.ts

@@ -215,14 +215,16 @@ export default abstract class StatementParser extends ExpressionParser {
     program.sourceType = sourceType;
     program.interpreter = this.parseInterpreterDirective();
     this.parseBlockBody(program, true, true, end);
-    if (
-      this.inModule &&
-      !this.options.allowUndeclaredExports &&
-      this.scope.undefinedExports.size > 0
-    ) {
-      for (const [localName, at] of Array.from(this.scope.undefinedExports)) {
-        this.raise(Errors.ModuleExportUndefined, at, { localName });
+    if (this.inModule) {
+      if (
+        !this.options.allowUndeclaredExports &&
+        this.scope.undefinedExports.size > 0
+      ) {
+        for (const [localName, at] of Array.from(this.scope.undefinedExports)) {
+          this.raise(Errors.ModuleExportUndefined, at, { localName });
+        }
       }
+      this.addExtra(program, "topLevelAwait", this.state.hasTopLevelAwait);
     }
     let finishedProgram: N.Program;
     if (end === tt.eof) {
@@ -490,7 +492,7 @@ export default abstract class StatementParser extends ExpressionParser {
       case tt._await:
         // [+Await] await [no LineTerminator here] using [no LineTerminator here] BindingList[+Using]
         if (!this.state.containsEsc && this.startsAwaitUsing()) {
-          if (!this.isAwaitAllowed()) {
+          if (!this.recordAwaitIfAllowed()) {
             this.raise(Errors.AwaitUsingNotInAsyncContext, node);
           } else if (!allowDeclaration) {
             this.raise(Errors.UnexpectedLexicalDeclaration, node);
@@ -912,8 +914,9 @@ export default abstract class StatementParser extends ExpressionParser {
 
     let awaitAt = null;
 
-    if (this.isAwaitAllowed() && this.eatContextual(tt._await)) {
-      awaitAt = this.state.lastTokStartLoc;
+    if (this.isContextual(tt._await) && this.recordAwaitIfAllowed()) {
+      awaitAt = this.state.startLoc;
+      this.next();
     }
     this.scope.enter(ScopeFlag.OTHER);
     this.expect(tt.parenL);
@@ -941,7 +944,7 @@ export default abstract class StatementParser extends ExpressionParser {
         let kind;
         if (startsWithAwaitUsing) {
           kind = "await using";
-          if (!this.isAwaitAllowed()) {
+          if (!this.recordAwaitIfAllowed()) {
             this.raise(Errors.AwaitUsingNotInAsyncContext, this.state.startLoc);
           }
           this.next(); // eat 'await'

packages/babel-parser/src/tokenizer/state.ts

@@ -37,6 +37,7 @@ const enum StateFlags {
   inFSharpPipelineDirectBody = 1 << 9,
   canStartJSXElement = 1 << 10,
   containsEsc = 1 << 11,
+  hasTopLevelAwait = 1 << 12,
 }
 
 export const enum LoopLabelKind {
@@ -45,7 +46,7 @@ export const enum LoopLabelKind {
 }
 
 export default class State {
-  flags: number = StateFlags.canStartJSXElement;
+  flags: StateFlags = StateFlags.canStartJSXElement;
 
   get strict(): boolean {
     return (this.flags & StateFlags.Strict) > 0;
@@ -261,6 +262,17 @@ export default class State {
   // that must be reported if the template is not tagged.
   firstInvalidTemplateEscapePos: null | Position = null;
 
+  get hasTopLevelAwait(): boolean {
+    return (this.flags & StateFlags.hasTopLevelAwait) > 0;
+  }
+  set hasTopLevelAwait(value: boolean) {
+    if (value) {
+      this.flags |= StateFlags.hasTopLevelAwait;
+    } else {
+      this.flags &= ~StateFlags.hasTopLevelAwait;
+    }
+  }
+
   // This property is used to track the following errors
   // - StrictNumericEscape
   // - StrictOctalLiteral

packages/babel-parser/test/fixtures/comments/basic/export-default-anonymous-class/output.json

@@ -60,7 +60,10 @@
         ]
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   },
   "comments": [
     {

packages/babel-parser/test/fixtures/comments/decorators/decorators-after-export/output.json

@@ -227,7 +227,10 @@
         ]
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   },
   "comments": [
     {

packages/babel-parser/test/fixtures/comments/decorators/decorators-before-export/output.json

@@ -227,7 +227,10 @@
         ]
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   },
   "comments": [
     {

packages/babel-parser/test/fixtures/comments/decorators/decorators-legacy-before-export/output.json

@@ -227,7 +227,10 @@
         ]
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   },
   "comments": [
     {

packages/babel-parser/test/fixtures/comments/interpreter-directive/interpreter-directive-import/output.json

@@ -41,6 +41,9 @@
         }
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/comments/regression/10892/output.json

@@ -60,7 +60,10 @@
         ]
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   },
   "comments": [
     {

packages/babel-parser/test/fixtures/core/opts/allowUndeclaredExports/output.json

@@ -30,6 +30,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/regression/non-octal-float-strict-mode/output.json

@@ -24,6 +24,9 @@
         }
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/dupl-bind-func-module-sloppy/output.json

@@ -54,6 +54,9 @@
         "directives": []
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/dupl-bind-func-module/output.json

@@ -47,6 +47,9 @@
         }
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-as-default/output.json

@@ -33,6 +33,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-as/output.json

@@ -51,6 +51,9 @@
         }
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-block/output.json

@@ -58,6 +58,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-builtin-as/output.json

@@ -33,6 +33,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-builtin/output.json

@@ -33,6 +33,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode-1/output.json

@@ -48,6 +48,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-function-loose-mode-2/output.json

@@ -48,6 +48,9 @@
         }
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-if/output.json

@@ -61,6 +61,9 @@
         "alternate": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export-var/output.json

@@ -54,6 +54,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/scope/undecl-export/output.json

@@ -33,6 +33,9 @@
         "declaration": null
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }

packages/babel-parser/test/fixtures/core/sourcetype-unambiguous/commonjs/output.json

@@ -44,6 +44,9 @@
         "kind": "var"
       }
     ],
-    "directives": []
+    "directives": [],
+    "extra": {
+      "topLevelAwait": false
+    }
   }
 }