Microsoft/TypeScript
Voir sur GitHubGenerated code when re-exporting a const enum inside a namespace using "preserveConstEnums": true leads to a runtime error
Open
#35 701 ouverte le 16 déc. 2019
BugDomain: JS EmitHelp Wanted
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Description
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