Testing the REST API Server

In addition to manually checking the server with curl, let’s add some structured tests using Go’s testing package. Go provides the package net/http/httptest with additional types and functions for testing HTTP servers.

One approach for testing HTTP servers is testing each handler function individually by using the type httptest.ResponseRecorder. This type allows the recording of an HTTP response for analysis or tests. This approach is useful if we’re using the DefaultServeMux as the server multiplexer.

Because we implemented our own multiplexer function, newMux(), we can use a different approach that allows integrated testing, including the route dispatching. We’ll use the type httptest.Server and instantiate a test server, providing the multiplexer function as input. This approach creates a test server with an URL that simulates our server, allowing us to make requests similarly to using curl on the actual server. Then we can analyze and test the responses to ensure the server works as designed.

Creating the new test file server_test.go

Since we’re going to create this test server multiple times, we’ll add a helper function to the test file to help with that. First, we create a new test file server_test.go, edit it, and add the package and import sections.

For these tests, we’ll use the following packages:

• io/ioutil to help read the response body.
• net/http to deal with HTTP requests and responses.
• net/http/httptest, which provides HTTP testing utilities.
• strings to compare strings.
• testing, which provides testing utilities.