handlers_test.go

func Test_IsPrimeHandler(t *testing.T) {
	handler := setupMux()

	type args struct {
		req *http.Request
	}

	tests := []struct {
		name     string
		args     func(t *testing.T) args
		wantCode int
		wantBody string
	}{
		{
			name: "must return http.StatusBadRequest to invalid number",
			args: func(*testing.T) args {
				req, err := http.NewRequest("GET", "/check-is-prime", nil)
				if err != nil {
					t.Fatalf("fail to create request: %s", err.Error())
				}

				q := req.URL.Query()
				q.Add("number", "not_number")
				req.URL.RawQuery = q.Encode()

				return args{
					req: req,
				}
			},
			wantCode: http.StatusBadRequest,
			wantBody: "invalid number\n",
		},
		{
			name: "must return http.StatusOk and true to prime number (7)",
			args: func(*testing.T) args {
				req, err := http.NewRequest("GET", "/check-is-prime", nil)
				if err != nil {
					t.Fatalf("fail to create request: %s", err.Error())
				}

				q := req.URL.Query()
				q.Add("number", "7")
				req.URL.RawQuery = q.Encode()

				return args{
					req: req,
				}
			},
			wantCode: http.StatusOK,
			wantBody: "true",
		},
		{
			name: "must return http.StatusOk and false because number (1) is not prime",
			args: func(*testing.T) args {
				req, err := http.NewRequest("GET", "/check-is-prime", nil)
				if err != nil {
					t.Fatalf("fail to create request: %s", err.Error())
				}

				q := req.URL.Query()
				q.Add("number", "1")
				req.URL.RawQuery = q.Encode()

				return args{
					req: req,
				}
			},
			wantCode: http.StatusOK,
			wantBody: "false",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			tArgs := tt.args(t)
			resp := httptest.NewRecorder()
			handler.ServeHTTP(resp, tArgs.req)

			if resp.Result().StatusCode != tt.wantCode {
				t.Fatalf("the status code should be [%d] but received [%d]", resp.Result().StatusCode, tt.wantCode)
			}

			if resp.Body.String() != tt.wantBody {
				t.Fatalf("the response body should be [%s] but received [%s]", resp.Body.String(), tt.wantBody)
			}

		})
	}
}