Microsoft/TypeScript
Auf GitHub ansehenGenerated code when re-exporting a const enum inside a namespace using "preserveConstEnums": true leads to a runtime error
Open
#35.701 geöffnet am 16. Dez. 2019
BugDomain: JS EmitHelp Wanted
Repository-Metriken
- Stars
- (48.455 Stars)
- PR-Merge-Metriken
- (Durchschn. Merge 6T 17h) (9 gemergte PRs in 30 T)
Beschreibung
TypeScript Version: 3.8.0-dev.20191216
Search Terms: const enum import export preserveConstEnums
Code
MyEnum.ts
const enum MyEnum {
FirstValue,
SecondValue
}
export default MyEnum;
ImportExportInNamespace.ts
import _MyEnum from "./MyEnum";
export namespace MyNamespace {
export import MyEnum = _MyEnum;
}
App.ts
import { MyNamespace } from "./ImportExportInNamespace";
console.log(MyNamespace.MyEnum.FirstValue);
Compile the above using
{
"compilerOptions": {
"target": "es5",
"module": "commonjs",
"preserveConstEnums": true
}
}
Expected behavior: ImportExportInNamespace.ts compiles to
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var MyEnum_1 = require("./MyEnum");
var MyNamespace;
(function (MyNamespace) {
MyNamespace.MyEnum = MyEnum_1.default;
})(MyNamespace = exports.MyNamespace || (exports.MyNamespace = {}));
Actual behavior: ImportExportInNamespace.ts wrongly compiles to
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var MyNamespace;
(function (MyNamespace) {
MyNamespace.MyEnum = MyEnum_1.default;
})(MyNamespace = exports.MyNamespace || (exports.MyNamespace = {}));
i.e. we are missing
var MyEnum_1 = require("./MyEnum");
If I change the enum not to be a const the code compiles correctly. I'm using it as a workaround.
Related Issues: #23514