tc39-weakrefs-shim/lib/index.js

Shim for TC39 Weakrefs proposal

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
var __importStar = (this && this.__importStar) || function (mod) {
    if (mod && mod.__esModule) return mod;
    var result = {};
    if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
    result["default"] = mod;
    return result;
};
Object.defineProperty(exports, "__esModule", { value: true });
const available_js_1 = __importDefault(require("./global/available.js"));
const available_js_2 = __importDefault(require("./node/available.js"));
const available_js_3 = __importDefault(require("./spidermonkey/available.js"));
function testKnownImplementationIssues(WeakRef, FinalizationGroup) {
    try {
        const finalizationGroup = new FinalizationGroup(() => { });
        if (finalizationGroup.unregister({}) !== false)
            return false;
        try {
            finalizationGroup.cleanupSome({});
            return false;
        }
        catch (err) { }
    }
    catch (err) {
        return false;
    }
    return true;
}
exports.available = available_js_1.default || available_js_3.default || available_js_2.default;
async function shim(wrapBrokenImplementation = true) {
    let implementation;
    if (available_js_1.default) {
        implementation = await Promise.resolve().then(() => __importStar(require("./global/index.js")));
        if (wrapBrokenImplementation &&
            !testKnownImplementationIssues(implementation.WeakRef, implementation.FinalizationGroup)) {
            implementation = (await Promise.resolve().then(() => __importStar(require("./wrapper.js")))).wrap(implementation.WeakRef, implementation.FinalizationGroup, implementation.gc);
        }
    }
    else if (available_js_3.default) {
        implementation = await Promise.resolve().then(() => __importStar(require("./spidermonkey/index.js")));
    }
    else if (available_js_2.default) {
        implementation = await Promise.resolve().then(() => __importStar(require("./node/index.js")));
    }
    else {
        implementation = { WeakRef: undefined, FinalizationGroup: undefined };
    }
    return implementation;
}
exports.shim = shim;
let asyncImportPromise;
// Easy use of the shim with dynamic import
function then(onfulfilled, onrejected) {
    if (!asyncImportPromise)
        asyncImportPromise = shim().then(exports => (Object.assign({ shim,
            available: exports.available }, exports)));
    return asyncImportPromise.then(onfulfilled, onrejected);
}
exports.then = then;
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