Function setup

github/github_test.go:71–135

setup sets up a test HTTP server along with a github.Client that is configured to talk to that test server. Tests should register handlers on mux which provide mock responses for the API method being tested.

(t *testing.T)

// configured to talk to that test server. Tests should register handlers on
// mux which provide mock responses for the API method being tested.
func setup(t *testing.T) (client *Client, mux *http.ServeMux, serverURL string) {
	t.Helper()
	// mux is the HTTP request multiplexer used with the test server.
	mux = http.NewServeMux()

	// We want to ensure that tests catch mistakes where the endpoint URL is
	// specified as absolute rather than relative. It only makes a difference
	// when there's a non-empty base URL path. So, use that. See issue #752.
	apiHandler := http.NewServeMux()
	apiHandler.Handle(baseURLPath+"/", http.StripPrefix(baseURLPath, mux))
	apiHandler.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
		fmt.Fprintln(os.Stderr, "FAIL: Client.BaseURL path prefix is not preserved in the request URL:")
		fmt.Fprintln(os.Stderr)
		fmt.Fprintln(os.Stderr, "\t"+req.URL.String())
		fmt.Fprintln(os.Stderr)
		fmt.Fprintln(os.Stderr, "\tDid you accidentally use an absolute endpoint URL rather than relative?")
		fmt.Fprintln(os.Stderr, "\tSee https://github.com/google/go-github/issues/752 for information.")
		http.Error(w, "Client.BaseURL path prefix is not preserved in the request URL.", http.StatusInternalServerError)
	})

	// server is a test HTTP server used to provide mock API responses.
	server := httptest.NewServer(apiHandler)

	testDialer := &net.Dialer{Timeout: 30 * time.Second}

	// Create a custom transport with isolated connection pool
	transport := &http.Transport{
		// Wrap dialed connections so transport does not take concrete-TCP sendfile fast paths
		// that can race under Windows + -race in upload tests.
		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
			conn, err := testDialer.DialContext(ctx, network, addr)
			if err != nil {
				return nil, err
			}
			return &raceSafeTestConn{Conn: conn}, nil
		},
		// Controls connection reuse - false allows reuse, true forces new connections for each request
		DisableKeepAlives: false,
		// Maximum concurrent connections per host (active + idle)
		MaxConnsPerHost: 10,
		// Maximum idle connections maintained per host for reuse
		MaxIdleConnsPerHost: 5,
		// Maximum total idle connections across all hosts
		MaxIdleConns: 20,
		// How long an idle connection remains in the pool before being closed
		IdleConnTimeout: 20 * time.Second,
	}

	// Create HTTP client with the isolated transport
	httpClient := &http.Client{
		Transport: transport,
		Timeout:   30 * time.Second,
	}
	// client is the GitHub client being tested and is
	// configured to use test server.
	client = mustNewClient(t, WithHTTPClient(httpClient))

	url, _ := url.Parse(server.URL + baseURLPath + "/")