Registry / testing / webextensions-api-mock

webextensions-api-mock

library1.0.0jsnpmunverified

Automatically generated sinon stubs for the WebExtensions API, designed to make browser extension testing easy. Version 1.0.0 uses the Firefox 72.0.2 schema and provides TypeScript types. Sinon is a peer dependency, not bundled, to avoid instanceof issues. Includes API and CLI to update schema to latest stable Firefox via webextensions-schema. Produces a fresh sandbox per call, with sinonSandbox exposed. Ideal for unit testing WebExtensions against sinon assertions and stubs.

testing

npm install webextensions-api-mock

github ↗package ↗

INSTALL

IMPORT

SIG · WEBEXTENSIONS-API-

webextensions-api-mock

testingjavascriptv1.0.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default (browserMock)

✓ import browserMock from 'webextensions-api-mock';

✗ const browserMock = require('webextensions-api-mock');

Package is ESM-first. For CommonJS, use const { default: browserMock } = require('webextensions-api-mock');

update

✓ import { update } from 'webextensions-api-mock';

✗ const { update } = require('webextensions-api-mock');

Named export for updating schema; also callable via CLI: webextensions-api-mock update

browserMock

✓ import browserMock from 'webextensions-api-mock'; const browser = browserMock();

✗ const browser = new browserMock();

browserMock is a function that creates a new browser object, not a constructor.

Creates a WebExtensions API mock, calls a method, asserts stub behavior, triggers event listeners, and resets history.

import browserMock from 'webextensions-api-mock'; import { assert } from 'sinon'; // Create a fresh browser mock const browser = browserMock(); // Simulate production code calling browser.tabs.create (browser.tabs.create as any)({ url: 'https://example.com' }); // Assert the stub was called assert(browser.tabs.create.calledOnce, 'tabs.create should have been called'); // Trigger an event listener browser.tabs.onCreated.addListener.yield(); // Reset all stubs via the sandbox browser.sinonSandbox.resetHistory();

Debug

Known issues

deprecatedSchema based on Firefox 72.0.2; newer APIs may be missing.

fix

Run `webextensions-api-mock update` to sync to latest Firefox stable schema, or manually update via API.

affects: >=1.0.0

gotchasinon is a peer dependency, not bundled; version mismatch can cause assertion errors due to instanceof checks.

fix

Install sinon as devDependency: npm install --save-dev sinon webextensions-api-mock

affects: >=1.0.0

gotchaEach call to browserMock() creates a new sinon sandbox; stubs are isolated. Reusing the same browser object across tests may cause state leakage.

fix

Create a new browserMock() in each test or use beforeEach to reset via browser.sinonSandbox.reset()

affects: >=1.0.0

gotchaEvent listeners are stubs with .addListener. Triggering with yield() works but does not simulate real event arguments.

fix

Pass mock arguments to yield() to simulate event data: browser.tabs.onCreated.addListener.yield({ id: 1, url: '...' });

affects: >=1.0.0

Errors

Common errors & fixes

Cannot find module 'sinon'

sinon is a peer dependency and not installed automatically.

fix

npm install --save-dev sinon@^7.5.0

browserMock is not a constructor

Attempting to use new browserMock() instead of calling it as a function.

fix

const browser = browserMock();

Cannot read property 'create' of undefined

Method namespace (e.g., tabs) not available because schema might not include it or upgrade needed.

fix

Run `webextensions-api-mock update` to get latest schema, or check Firefox version compatibility.

browser.sinonSandbox.resetHistory is not a function

Property name typo (e.g., sinonSandbox vs sinonSandbox).

fix

Use browser.sinonSandbox.resetHistory() (note: 'sinonSandbox' with capital S).

Upgrade

Version history

1.0.0latest on npm

Audit

Dependencies

sinonrequiredPeer dependency: sinon stubs are used for mocking. Must be installed separately to avoid instanceof issues.

Agent activity

15 hits · last 30 days

node

Resources

githubhttps://github.com/stoically/webextensions-api-mock ↗

packagehttps://www.npmjs.com/package/webextensions-api-mock ↗