Call history

fetchMock.callHistory is an object used to record the history of all calls handled by fetchMock.fetchHandler.

CallLog schema

Calls are recorded, and returned, in a standard format with the following properties:

• arguments [string|Request,Object] - the original arguments passed in to fetch
• url {string} - The url being fetched
• options {NormalizedRequestOptions} - The options passed in to the fetch (may be derived from a Request if one was used)
• request {Request} - The Request passed to fetch, if one was used
• route {Route} - The route used to handle the request
• response {Response} - The Response returned to the user
• expressParams {Object.<string,string>} - Any express parameters extracted from the url
• queryParams {URLSearchParams} - Any query parameters extracted from the url
• pendingPromises {Promise<any>[]} - An internal structure used by the .flush() method documented below

Filtering

Most of fetchMock.callHistory's methods take two arguments — (filter, options) — which allow fetch calls to be extracted and examined.

filter

Filter calls to fetch using one of the following criteria:

undefined

Retrieve all calls made to fetch

true / "matched"

Retrieve all calls to fetch matched by some route defined by fetch-mock. The string 'matched' can be used instead of true to make tests more readable

false / "unmatched"

Retrieve all calls to fetch not matched by some route defined by fetch-mock, i.e. calls that are handled by .catch(). The string 'unmatched' can be used instead of false to make tests more readable

name

{String}

Retrieve all calls to fetch matched by a particular named route.

matcher

{String|RegExp|function|Object} Any matcher compatible with the route api can be passed in to filter the calls arbitrarily.

options

{Object}

An options object compatible with the route api to be used to filter the list of calls further.

Methods

fetchMock.callHistory exposes the following methods.

Note that fetch calls made using (url, options) pairs are added synchronously, but calls using a Request are added asynchronously. This is because when a Request is used access to many of its internals is via asynchronous methods, while for an options object they can be read directly. In general it's best to await your application code to complete before attempting to access call history.

.recordCall(callLog)

For internal use.

.calls(filter, options)

Returns an array of all calls matching the given filter and options. Each call is returned as a CallLog.

.called(filter, options)

Returns a Boolean indicating whether any calls to fetch matched the given filter and options

.lastCall(filter, options)

Returns the CallLog for the last call to fetch matching the given filter and options.

.done(routeNames)

Returns a Boolean indicating whether fetch was called the expected number of times (or has been called at least once if repeat is not defined for the route). It does not take into account whether the fetches completed successfully.

A single name or an array of names can be passed in the routeNames parameter to check only certain routes. If no routeNames are passed it runs over all routes.

.flush(waitForBody)

Returns a Promise that resolves once all fetches handled by fetch-mock have resolved

Useful for testing code that uses fetch but where the returned promise cannot be accessed from your tests.

If waitForBody is true, the promise will wait for all body parsing methods (res.json(), res.text(), etc.) to resolve too.