[Feature] make generated codes from enum could be minified when not used

Search Terms

For now TypeScript will transform enum from

enum Test {
    Key = 1
}

to

var Test;
(function (Test) {
    Test[Test["Key"] = 1] = "Key";
})(Test || (Test = {}));

This result is not friendly for uglyify or tree-shaking.
When Test is not be used, the generated code block always remain as dead codes.

Suggestion

prefer to generate codes below:

var Test = /*#__PURE__*/(function () {
    var e = {}
    e[e["Key"] = 1] = "Key";
    return e
})();

Examples

The suggestion version will be removed.

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript / JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. new expression-level syntax)

Non viene indicato alcun file sorgente, test o punto di ingresso. Inizia individuando l’enum emitter di TypeScript e i test esistenti dell’output degli enum, quindi confronta la forma emessa con il comportamento del minifier e del tree-shaking. Il lavoro è completato quando una strategia di emissione concordata è coperta da test di regressione senza modificare il comportamento a runtime.