Parse body of module blocks as Program

packages/babel-generator/src/generators/expressions.js

@@ -274,13 +274,11 @@ export function ModuleExpression(node: Object) {
   this.word("module");
   this.space();
   this.token("{");
-  if (node.body.length === 0) {
+  if (node.body.body.length === 0) {
     this.token("}");
   } else {
     this.newline();
-    this.printSequence(node.body, node, {
-      indent: true,
-    });
+    this.printSequence(node.body.body, node, { indent: true });
     this.rightBrace();
   }
 }

packages/babel-parser/ast/spec.md

@@ -1092,7 +1092,7 @@ interface DoExpression <: Expression {
 ```js
 interface ModuleExpression <: Expression {
   type: "ModuleExpression";
-  body: [ Statement ];
+  body: Program
 }
 ```
 

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

@@ -40,7 +40,6 @@ import {
   SCOPE_FUNCTION,
   SCOPE_SUPER,
   SCOPE_PROGRAM,
-  SCOPE_OTHER,
 } from "../util/scopeflags";
 import { ExpressionErrors } from "./util";
 import {
@@ -57,6 +56,10 @@ import {
 } from "../util/expression-scope.js";
 import { Errors } from "./error";
 
+/*::
+import type { SourceType } from "../options";
+*/
+
 export default class ExpressionParser extends LValParser {
   // Forward-declaration: defined in statement.js
   /*::
@@ -86,6 +89,9 @@ export default class ExpressionParser extends LValParser {
     end: TokenType,
     afterBlockParse?: (hasStrictModeDirective: boolean) => void
   ) => void
+  +parseProgram: (
+    program: N.Program, end: TokenType, sourceType?: SourceType
+  ) => N.Program
   */
 
   // For object literal, check if property __proto__ has been used more than once.
@@ -2633,23 +2639,26 @@ export default class ExpressionParser extends LValParser {
   parseModuleExpression(): N.ModuleExpression {
     this.expectPlugin("moduleBlocks");
     const node = this.startNode<N.ModuleExpression>();
-    node.body = [];
     this.next(); // eat "module"
     const oldLabels = this.state.labels;
     this.state.labels = [];
     const oldExportedIdentifiers = this.state.exportedIdentifiers;
     this.state.exportedIdentifiers = [];
     this.eat(tt.braceL);
-    this.scope.enter(SCOPE_OTHER);
+    this.scope.enter(SCOPE_PROGRAM);
+    const oldUndefinedExports = this.scope.undefinedExports;
+    this.scope.undefinedExports = new Map();
     let paramFlags = PARAM;
     if (this.hasPlugin("topLevelAwait")) {
       paramFlags |= PARAM_AWAIT;
     }
     this.prodParam.enter(paramFlags);
     const oldInModule = this.inModule;
     this.inModule = true;
-    this.parseBlockOrModuleBlockBody(node.body, undefined, true, tt.braceR);
+    const program = this.startNode<N.Program>();
+    node.body = this.parseProgram(program, tt.braceR, "module");
     this.scope.exit();
+    this.scope.undefinedExports = oldUndefinedExports;
     this.prodParam.exit();
     this.inModule = oldInModule;
     this.eat(tt.braceR);

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

@@ -34,6 +34,7 @@ import {
   newExpressionScope,
   newParameterDeclarationScope,
 } from "../util/expression-scope";
+import type { SourceType } from "../options";
 
 const loopLabel = { kind: "loop" },
   switchLabel = { kind: "switch" };
@@ -54,12 +55,22 @@ export default class StatementParser extends ExpressionParser {
   // to its body instead of creating a new node.
 
   parseTopLevel(file: N.File, program: N.Program): N.File {
-    program.sourceType = this.options.sourceType;
+    file.program = this.parseProgram(program);
+    file.comments = this.state.comments;
 
-    program.interpreter = this.parseInterpreterDirective();
+    if (this.options.tokens) file.tokens = this.tokens;
 
-    this.parseBlockBody(program, true, true, tt.eof);
+    return this.finishNode(file, "File");
+  }
 
+  parseProgram(
+    program: N.Program,
+    end: TokenType = tt.eof,
+    sourceType: SourceType = this.options.sourceType,
+  ): N.Program {
+    program.sourceType = sourceType;
+    program.interpreter = this.parseInterpreterDirective();
+    this.parseBlockBody(program, true, true, end);
     if (
       this.inModule &&
       !this.options.allowUndeclaredExports &&
@@ -71,13 +82,7 @@ export default class StatementParser extends ExpressionParser {
         this.raise(pos, Errors.ModuleExportUndefined, name);
       }
     }
-
-    file.program = this.finishNode(program, "Program");
-    file.comments = this.state.comments;
-
-    if (this.options.tokens) file.tokens = this.tokens;
-
-    return this.finishNode(file, "File");
+    return this.finishNode<N.Program>(program, "Program");
   }
 
   // TODO

packages/babel-parser/src/types.js

@@ -657,7 +657,7 @@ export type TemplateElement = NodeBase & {
 
 export type ModuleExpression = NodeBase & {
   type: "ModuleExpression",
-  body: Array<Statement>,
+  body: Program,
 };
 
 // Patterns

packages/babel-parser/src/util/scope.js

@@ -170,13 +170,16 @@ export default class ScopeHandler<IScope: Scope = Scope> {
   }
 
   checkLocalExport(id: N.Identifier) {
+    const currentScope = this.currentScope();
+    const scope =
+      currentScope.flags & SCOPE_PROGRAM ? currentScope : this.scopeStack[0];
     if (
-      this.scopeStack[0].lexical.indexOf(id.name) === -1 &&
-      this.scopeStack[0].var.indexOf(id.name) === -1 &&
+      scope.lexical.indexOf(id.name) === -1 &&
+      scope.var.indexOf(id.name) === -1 &&
       // In strict mode, scope.functions will always be empty.
       // Modules are strict by default, but the `scriptMode` option
       // can overwrite this behavior.
-      this.scopeStack[0].functions.indexOf(id.name) === -1
+      scope.functions.indexOf(id.name) === -1
     ) {
       this.undefinedExports.set(id.name, id.start);
     }

packages/babel-parser/test/fixtures/experimental/module-blocks/invalid-await-label-in-module-blocks/output.json

@@ -16,30 +16,37 @@
         "expression": {
           "type": "ModuleExpression",
           "start":0,"end":19,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":19}},
-          "body": [
-            {
-              "type": "LabeledStatement",
-              "start":9,"end":17,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":17}},
-              "body": {
-                "type": "ExpressionStatement",
-                "start":16,"end":17,"loc":{"start":{"line":1,"column":16},"end":{"line":1,"column":17}},
-                "expression": {
-                  "type": "NumericLiteral",
+          "body": {
+            "type": "Program",
+            "start":9,"end":19,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":19}},
+            "sourceType": "module",
+            "interpreter": null,
+            "body": [
+              {
+                "type": "LabeledStatement",
+                "start":9,"end":17,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":17}},
+                "body": {
+                  "type": "ExpressionStatement",
                   "start":16,"end":17,"loc":{"start":{"line":1,"column":16},"end":{"line":1,"column":17}},
-                  "extra": {
-                    "rawValue": 3,
-                    "raw": "3"
-                  },
-                  "value": 3
+                  "expression": {
+                    "type": "NumericLiteral",
+                    "start":16,"end":17,"loc":{"start":{"line":1,"column":16},"end":{"line":1,"column":17}},
+                    "extra": {
+                      "rawValue": 3,
+                      "raw": "3"
+                    },
+                    "value": 3
+                  }
+                },
+                "label": {
+                  "type": "Identifier",
+                  "start":9,"end":14,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":14},"identifierName":"await"},
+                  "name": "await"
                 }
-              },
-              "label": {
-                "type": "Identifier",
-                "start":9,"end":14,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":14},"identifierName":"await"},
-                "name": "await"
               }
-            }
-          ]
+            ],
+            "directives": []
+          }
         }
       }
     ],

packages/babel-parser/test/fixtures/experimental/module-blocks/invalid-duplicated-exports-in-blocks/output.json

@@ -2,8 +2,7 @@
   "type": "File",
   "start":0,"end":67,"loc":{"start":{"line":1,"column":0},"end":{"line":4,"column":2}},
   "errors": [
-    "SyntaxError: `foo` has already been exported. Exported identifiers must be unique. (3:11)",
-    "SyntaxError: Export 'foo' is not defined (3:11)"
+    "SyntaxError: `foo` has already been exported. Exported identifiers must be unique. (3:11)"
   ],
   "program": {
     "type": "Program",
@@ -26,61 +25,68 @@
             "init": {
               "type": "ModuleExpression",
               "start":10,"end":66,"loc":{"start":{"line":1,"column":10},"end":{"line":4,"column":1}},
-              "body": [
-                {
-                  "type": "ExportNamedDeclaration",
-                  "start":21,"end":46,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":27}},
-                  "specifiers": [],
-                  "source": null,
-                  "declaration": {
-                    "type": "VariableDeclaration",
-                    "start":28,"end":46,"loc":{"start":{"line":2,"column":9},"end":{"line":2,"column":27}},
-                    "declarations": [
+              "body": {
+                "type": "Program",
+                "start":21,"end":66,"loc":{"start":{"line":2,"column":2},"end":{"line":4,"column":1}},
+                "sourceType": "module",
+                "interpreter": null,
+                "body": [
+                  {
+                    "type": "ExportNamedDeclaration",
+                    "start":21,"end":46,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":27}},
+                    "specifiers": [],
+                    "source": null,
+                    "declaration": {
+                      "type": "VariableDeclaration",
+                      "start":28,"end":46,"loc":{"start":{"line":2,"column":9},"end":{"line":2,"column":27}},
+                      "declarations": [
+                        {
+                          "type": "VariableDeclarator",
+                          "start":34,"end":45,"loc":{"start":{"line":2,"column":15},"end":{"line":2,"column":26}},
+                          "id": {
+                            "type": "Identifier",
+                            "start":34,"end":37,"loc":{"start":{"line":2,"column":15},"end":{"line":2,"column":18},"identifierName":"foo"},
+                            "name": "foo"
+                          },
+                          "init": {
+                            "type": "StringLiteral",
+                            "start":40,"end":45,"loc":{"start":{"line":2,"column":21},"end":{"line":2,"column":26}},
+                            "extra": {
+                              "rawValue": "foo",
+                              "raw": "\"foo\""
+                            },
+                            "value": "foo"
+                          }
+                        }
+                      ],
+                      "kind": "const"
+                    }
+                  },
+                  {
+                    "type": "ExportNamedDeclaration",
+                    "start":49,"end":64,"loc":{"start":{"line":3,"column":2},"end":{"line":3,"column":17}},
+                    "specifiers": [
                       {
-                        "type": "VariableDeclarator",
-                        "start":34,"end":45,"loc":{"start":{"line":2,"column":15},"end":{"line":2,"column":26}},
-                        "id": {
+                        "type": "ExportSpecifier",
+                        "start":58,"end":61,"loc":{"start":{"line":3,"column":11},"end":{"line":3,"column":14}},
+                        "local": {
                           "type": "Identifier",
-                          "start":34,"end":37,"loc":{"start":{"line":2,"column":15},"end":{"line":2,"column":18},"identifierName":"foo"},
+                          "start":58,"end":61,"loc":{"start":{"line":3,"column":11},"end":{"line":3,"column":14},"identifierName":"foo"},
                           "name": "foo"
                         },
-                        "init": {
-                          "type": "StringLiteral",
-                          "start":40,"end":45,"loc":{"start":{"line":2,"column":21},"end":{"line":2,"column":26}},
-                          "extra": {
-                            "rawValue": "foo",
-                            "raw": "\"foo\""
-                          },
-                          "value": "foo"
+                        "exported": {
+                          "type": "Identifier",
+                          "start":58,"end":61,"loc":{"start":{"line":3,"column":11},"end":{"line":3,"column":14},"identifierName":"foo"},
+                          "name": "foo"
                         }
                       }
                     ],
-                    "kind": "const"
+                    "source": null,
+                    "declaration": null
                   }
-                },
-                {
-                  "type": "ExportNamedDeclaration",
-                  "start":49,"end":64,"loc":{"start":{"line":3,"column":2},"end":{"line":3,"column":17}},
-                  "specifiers": [
-                    {
-                      "type": "ExportSpecifier",
-                      "start":58,"end":61,"loc":{"start":{"line":3,"column":11},"end":{"line":3,"column":14}},
-                      "local": {
-                        "type": "Identifier",
-                        "start":58,"end":61,"loc":{"start":{"line":3,"column":11},"end":{"line":3,"column":14},"identifierName":"foo"},
-                        "name": "foo"
-                      },
-                      "exported": {
-                        "type": "Identifier",
-                        "start":58,"end":61,"loc":{"start":{"line":3,"column":11},"end":{"line":3,"column":14},"identifierName":"foo"},
-                        "name": "foo"
-                      }
-                    }
-                  ],
-                  "source": null,
-                  "declaration": null
-                }
-              ]
+                ],
+                "directives": []
+              }
             }
           }
         ],

packages/babel-parser/test/fixtures/experimental/module-blocks/invalid-undefined-export-in-module-blocks/input.js

@@ -0,0 +1,3 @@
+module {
+  export { foo }
+}