General setup - Sinon.JS

We will be making fakes, spies and stubs. By default these are created in the default sandbox. Be sure to restore this sandbox after each test.

For example, if you’re using mocha you can place this in a test file at the root level:

afterEach(() => {
  // Restore the default sandbox here
  sinon.restore();
});

On Mocha v8.0.0 or newer you can now add a root hook to your entire test suite, which will execute before/after every test:

// tests/hooks.js

// Restores the default sandbox after every test
exports.mochaHooks = {
  afterEach() {
    sinon.restore();
  },
};

This root file needs to be loaded using the --require option:

mocha --require tests/hooks.js

Or in Jasmine you should place it in each describe:

describe("My test suite", () => {
  afterEach(() => {
    // Restore the default sandbox here
    sinon.restore();
  });
});

Forgetting to restore your sandbox results in a memory leak.

For more advanced setups using multiple sandboxes, please see sandbox