nock-uri-template
v0.1.8
Published
This library provides an extension to the [nock](https://github.com/nock/nock) library to make it easy to mock urls using uri templates instead of using only regexes with nock.
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nock-uri-template
This library provides an extension to the nock library to make it easy to mock urls using uri templates instead of using only regexes with nock.
Installation
For NPM:
npm install --save-dev nock-uri-template
For yarn
yarn add nock-uri-template -D
URI Template
The first step is to determine the API urls you want to mock. To do so, you must use the uri template standard.
Here are some examples of uri templates:
- /products/{id}{?category} would match
- /products/1
- /products/11
- /products/1?category=true
- /products/{type}/{category}
- /products/tools/electric
Under the hood, nock-uri-template uses this library to match uri templates.
Mocking an api
Here is an example of how to mock an API
const scope = nockUriTemplate("http://localhost:4001")
.get("/api/products/{id}")
.reply(
(params: any): Response => ({
payload: { id: "1" }
})
);
The first line is used to specify the base url of the service. This base url must match the config used for your http calls in your code.
The second line specify we want to mock GET requests to the specified path.
The third line uses a function to create the return payload. The object returned by the function can have a code
property for the http return code, and a payload
property if there is a payload to return. If no code is provided,
a 200 will be returned if there is a payload, and a 204 if there is no payload.
Limit the number of calls
Using the reply
method will make the mock API reply to an unlimited number of calls. If you want to limit the number
of calls the mock API will reply to, you can use replyOnce
or replyTimes
method and provide a maximum number.
Expectations
Whatever test runner you are using, nock-uri-template provides an object to make assertions on. Using the object returned by
nockUriTemplate
, you can expect on the calls made to the api. The following examples are using Jest, but they work with
any runner.
Expecting on calls made using certain parameters
This would expect that one call was made to our api endpoint using the parameter id=1
expect(scope.forParams({ id: "1" }).times()).toBe(1);
We could also verify that no calls were made except the call to id=1
expect(scope.notForParams({ id: "1" }).times()).toBe(0);
expect(scope.notForParams({ id: "1" }).urls()).toEqual([]);
The two lines test the same assertion, but it's easier to debug using the urls
method, because
the runner will print the difference between the two arrays, which will print out the list of urls that were not
supposed to be called.