This is a pure JS in-memory implementation of the IndexedDB 2.0 API (which technically still is a draft, but is probably not going to substantially change). Its main utility is for testing IndexedDB-dependent code in Node.js.
npm install --save-dev fake-indexeddb
or
yarn add --dev fake-indexeddb
Functionally, it works exactly like IndexedDB except data is not persisted to disk.
var indexedDB = require("fake-indexeddb");
var IDBKeyRange = require("fake-indexeddb/lib/FDBKeyRange");
var request = indexedDB.open("test", 3);
request.onupgradeneeded = function () {
var db = request.result;
var store = db.createObjectStore("books", {keyPath: "isbn"});
store.createIndex("by_title", "title", {unique: true});
store.put({title: "Quarry Memories", author: "Fred", isbn: 123456});
store.put({title: "Water Buffaloes", author: "Fred", isbn: 234567});
store.put({title: "Bedrock Nights", author: "Barney", isbn: 345678});
}
request.onsuccess = function (event) {
var db = event.target.result;
var tx = db.transaction("books");
tx.objectStore("books").index("by_title").get("Quarry Memories").addEventListener("success", function (event) {
console.log("From index:", event.target.result);
});
tx.objectStore("books").openCursor(IDBKeyRange.lowerBound(200000)).onsuccess = function (event) {
var cursor = event.target.result;
if (cursor) {
console.log("From cursor:", cursor.value);
cursor.continue();
}
};
tx.oncomplete = function () {
console.log("All done!");
};
};
When importing individual classes directly (like var IDBKeyRange = require("fake-indexeddb/lib/FDBKeyRange");
above), file names of all the objects are like the normal IndexedDB ones except with F replacing I, e.g. FDBIndex
instead of IDBIndex
.
Here's a comparison of fake-indexeddb and real browser IndexedDB implementations on the W3C IndexedDB test suite as of March 14, 2019:
Implementation | Percentage of files that pass completely |
---|---|
Chrome 73 | 99% |
Firefox 65 | 97% |
Safari 12 | 92% |
fake-indexeddb 2 | 85% |
Edge 18 | 61% |
For browsers, I ran http://w3c-test.org/tools/runner/index.html and counted the passes. For fake-indexeddb, I ran npm run test-w3c
.
85% is pretty good, right? Especially considering that fake-indexeddb runs in Node.js where failure is guaranteed for tests involving browser APIs like Web Workers. There are definitley still some weak points of fake-indexeddb, most of which are described in src/test/web-platform-tests/run-all.js
. Your app will probably run fine, though.
-
Use as a mock database in unit tests.
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Use the same API in Node.js and in the browser.
-
Support IndexedDB in old or crappy browsers.
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Somehow use it within a caching layer on top of IndexedDB in the browser, since IndexedDB can be kind of slow.
-
Abstract the core database functions out, so what is left is a shell that allows the IndexedDB API to easily sit on top of many different backends.
-
Serve as a playground for experimenting with IndexedDB.
Apache 2.0