Testing simple web server

#go #testing #webdev

Testing web server in Golang

create a file with name<anything>_test.go, these files are ignore by compiler
write a func matchingfunc TestXxx(*testing.T) where Xxx does not start with a lowercase letter. The function name serves to identify the test routine.
to run the test :go test

Testing

inorder to test the handler, we call it by passinghttp.ResponseWriter and*http.Request
to create a new Request

req, err := http.NewRequest(    http.MethodGet,                 // defining method of HTTP request    "http://localhost:8080/",       // Url to hit    nil,                            // Body (taking nil right now))// checking for any errors            if err != nil {    t.Fatalf("Could not create a request %v", err)}

to record the response from the writer

rec := httptest.NewRecorder()

to verify

// calling the functionhelloWorldEndPoint(rec, req)// checking status codeif rec.Code != http.StatusOK {    t.Errorf("accepted status 200, got %v", rec.Code)}// checking the msg returnedif !strings.Contains(rec.Body.String(), "hello world") {    t.Errorf("unexpected body in response %q", rec.Body.String())}

Full code server.go

package mainimport (    "fmt"    "log"    "net/http")func main() {    http.HandleFunc("/", helloWorldEndPoint)    fmt.Println("Server :  http://localhost:8080")    log.Fatal(http.ListenAndServe(":8080", nil))}func helloWorldEndPoint(writer http.ResponseWriter, request *http.Request) {    fmt.Fprintf(writer, "hello world")}

full code main_test.go

package mainimport (    "net/http"    "net/http/httptest"    "strings"    "testing")func TestHandler(t *testing.T) {    req, err := http.NewRequest(        http.MethodGet,        "http://localhost:8080/",        nil,    )    if err != nil {        t.Fatalf("Could not create a request %v", err)    }    rec := httptest.NewRecorder()    helloWorldEndPoint(rec, req)    if rec.Code != http.StatusOK {        t.Errorf("accepted status 200, got %v", rec.Code)    }    if !strings.Contains(rec.Body.String(), "hello world") {        t.Errorf("unexpected body in response %q", rec.Body.String())    }}