Introduce initializeScopes

babel · Feb 12, 2021 · f651952 · f651952
1 parent 0feadb0
commit f651952
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Showing 2 changed files with 33 additions and 24 deletions.
diff --git a/packages/babel-parser/src/parser/expression.js b/packages/babel-parser/src/parser/expression.js
@@ -54,7 +54,6 @@ import {
   newAsyncArrowScope,
   newExpressionScope,
 } from "../util/expression-scope";
-import ClassScopeHandler from "../util/class-scope";
 import { Errors } from "./error";
 
 /*::
@@ -2657,33 +2656,12 @@ export default class ExpressionParser extends LValParser {
     this.expectPlugin("moduleBlocks");
     const node = this.startNode<N.ModuleExpression>();
     this.next(); // eat "module"
-    const oldLabels = this.state.labels;
-    this.state.labels = [];
-    const oldExportedIdentifiers = this.state.exportedIdentifiers;
-    this.state.exportedIdentifiers = [];
     this.expect(tt.braceL);
-    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;
-    const oldClassScope = this.classScope;
-    this.classScope = new ClassScopeHandler(this.raise.bind(this));
+    const revertScopes = this.initializeScopes();
     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);
-    this.state.labels = oldLabels;
-    this.state.exportedIdentifiers = oldExportedIdentifiers;
-    this.classScope = oldClassScope;
+    revertScopes();
     return this.finishNode<N.ModuleExpression>(node, "ModuleExpression");
   }
 }
diff --git a/packages/babel-parser/src/parser/util.js b/packages/babel-parser/src/parser/util.js
@@ -6,6 +6,9 @@ import State from "../tokenizer/state";
 import type { Node } from "../types";
 import { lineBreak } from "../util/whitespace";
 import { isIdentifierChar } from "../util/identifier";
+import ClassScopeHandler from "../util/class-scope";
+import { SCOPE_PROGRAM } from "../util/scopeflags";
+import { PARAM_AWAIT, PARAM } from "../util/production-parameter";
 import { Errors } from "./error";
 
 type TryParse<Node, Error, Thrown, Aborted, FailState> = {
@@ -304,6 +307,34 @@ export default class UtilParser extends Tokenizer {
   isObjectMethod(node: Node): boolean {
     return node.type === "ObjectMethod";
   }
+
+  initializeScopes() {
+    const oldLabels = this.state.labels;
+    this.state.labels = [];
+    const oldExportedIdentifiers = this.state.exportedIdentifiers;
+    this.state.exportedIdentifiers = [];
+    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;
+    const oldClassScope = this.classScope;
+    this.classScope = new ClassScopeHandler(this.raise.bind(this));
+    return () => {
+      this.scope.exit();
+      this.scope.undefinedExports = oldUndefinedExports;
+      this.prodParam.exit();
+      this.inModule = oldInModule;
+      this.state.labels = oldLabels;
+      this.state.exportedIdentifiers = oldExportedIdentifiers;
+      this.classScope = oldClassScope;
+    };
+  }
 }
 
 /**