Resetting

The methods below can be used to restore some or all of fetchMock's behaviour toits default state.

.hardReset(options)

Removes all the behaviour and state that's been added so far. It runs .removeRoutes(), .clearHistory() and .unmockGlobal(). Pass {includeSticky: true} to force even sticky routes to be removed.

.removeRoutes(options)

This method removes some or all of the routes that have been added to fetch mock. It accepts the following options.

names

An array of named routes to remove. If no value is passed then all routes compatible with the other options passed are removed.

includeSticky

A boolean indicating whether or not to remove sticky routes.

includeFallback

A boolean indicating whether or not to remove the fallback route (added using .catch())

.clearHistory()

Clears all data recorded for fetch's calls.

.unmockGlobal()

Restores global fetch to its original state if .mockGlobal() or .spyGlobal() have been used .

.createInstance()

Can be used to create a standalone instance of fetch mock that is completely independent of other instances.

In older environments - where fetch was not a global and test files often ran in a shared process - this was very useful for increasing parallelisation. But in more modern setups - global fetch and isolated processes per test file - it's less relevant.

It can however be used as an alternative to fetchMock.removeRoutes().clearHistory() by creating a completely new fetchMock instance and swapping this for the previously used one.

It can also be used to "fork" a previous instance as routes are cloned from one instance to another. However call history is always reset for new instances.

fetchMock.route('http://my.site', 200);
fetchMock.fetchHandler('http://my.site');

const newFM = fetchMock.createInstance();

newFM.routes.routes; // Array[1]
newFM.callHistory.calls(); // Array[0]