fake-indexeddb
Version:
Fake IndexedDB: a pure JS in-memory implementation of the IndexedDB API
36 lines (34 loc) • 1.59 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.queueTask = void 0;
// When running within Node.js (including jsdom), we want to use setImmediate
// (which runs immediately) rather than setTimeout (which enforces a minimum
// delay of 1ms, and on Windows only has a resolution of 15ms or so). jsdom
// doesn't provide setImmediate (to better match the browser environment) and
// sandboxes scripts, but its sandbox is by necessity imperfect, so we can break
// out of it:
//
// - https://github.com/jsdom/jsdom#executing-scripts
// - https://github.com/jsdom/jsdom/issues/2729
// - https://github.com/scala-js/scala-js-macrotask-executor/pull/17
function getSetImmediateFromJsdom() {
if (typeof navigator !== "undefined" && /jsdom/.test(navigator.userAgent)) {
const outerRealmFunctionConstructor = Node.constructor;
return new outerRealmFunctionConstructor("return setImmediate")();
} else {
return undefined;
}
}
// Schedules a task to run later. Use Node.js's setImmediate if available and
// setTimeout otherwise. Note that options like process.nextTick or
// queueMicrotask will likely not work: IndexedDB semantics require that
// transactions are marked as not active when the event loop runs. The next
// tick queue and microtask queue run within the current event loop macrotask,
// so they'd process database operations too quickly.
const queueTask = fn => {
const setImmediate = globalThis.setImmediate || getSetImmediateFromJsdom() || (fn => setTimeout(fn, 0));
setImmediate(fn);
};
exports.queueTask = queueTask;