How to re-export an enum under a different name in Typescript?

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I'd like to provide a simpler interface in my library (in a React application) for exported members of another library (monaco-editor in this case). For this I created an index.ts file which does re-export a number of types, where I removed an inner namespace. This works nicely:

import { languages } from "monaco-editor/esm/vs/editor/editor.api";

export type FoldingRange = languages.FoldingRange;
export type FoldingContext = languages.FoldingContext;
export type FoldingRangeKind = languages.FoldingRangeKind;

except for the last line, because FoldingRangeKind is an enum. I cannot use export enum here as that expects a full enum definition.

Another option would be:

export import FoldingRangeKind = languages.FoldingRangeKind;

but unfortunately, this is not accepted by Babel. It results in this error:

import =is not supported by @babel/plugin-transform-typescript Please consider usingimport from '';` alongside Typescript's --allowSyntheticDefaultImports option.

A default import wouldn't help here, so I wonder what to do instead.

typescript enums
1 Answers

Enum is not a type, but an object. Its values are values too, thus you need to assign them to constant instead.

enum languages {
    FoldingRange,
    FoldingContext,
    FoldingRangeKind
}

export const FoldingRange = languages.FoldingRange;
export const FoldingContext = languages.FoldingContext;
export const FoldingRangeKind = languages.FoldingRangeKind;

interface iLanguages {
    FoldingRange: 0,
    FoldingContext: 1,
}

export type FoldingRange = iLanguages["FoldingRange"];
export type FoldingContext = iLanguages["FoldingContext"];
export type FoldingRangeKind = languages.FoldingRangeKind;

This is what is then compiled (playground). Hopefully, this clears it up for you.

var languages;
(function (languages) {
    languages[languages["FoldingRange"] = 0] = "FoldingRange";
    languages[languages["FoldingContext"] = 1] = "FoldingContext";
    languages[languages["FoldingRangeKind"] = 2] = "FoldingRangeKind";
})(languages || (languages = {}));

export const FoldingRange = languages.FoldingRange;
export const FoldingContext = languages.FoldingContext;
export const FoldingRangeKind = languages.FoldingRangeKind;
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