[INFO] Tests missing in Gin Challenge 2

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In the Gin Challenge 2 there are missing tests.

The RateLimitMiddleware is not correctly tested, all tests are passing without implementing the RateLimitMiddleware function.

The ErrorMiddleware is not tested, all tests are passing without implementing it.

If you are interested to fix those missing tests I already wrote them, see the comments below, you can take inspiration from them.

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// Test Error Middleware
func TestErrorMiddleware(t *testing.T) {
	// Specific router to test the Error middleware.
	// To simulate an internal server error we will use a divide by zero trick and
	// check if the Error middleware is doing his job correctly by returning
	// a code 500 with correct JSON message.
	gin.SetMode(gin.TestMode)
	router := gin.New()
	router.Use(RequestIDMiddleware())
	router.Use(ErrorHandlerMiddleware())
	router.GET("/div/:a/:b", func (c *gin.Context) {
		a, _ := strconv.Atoi(c.Param("a"))
		b, _ := strconv.Atoi(c.Param("b"))
		val := a / b   // No check on 'b' value, we want to allow a div by zero
		c.JSON(http.StatusOK, APIResponse{Success: true, Data: val})
	})

	w := httptest.NewRecorder()
	// a = 5, b = 0     a / b --> booom
	req, _ := http.NewRequest("GET", "/div/5/0)", nil)
	router.ServeHTTP(w, req)

	requestID := w.Header().Get("X-Request-ID")
	assert.NotEmpty(t, requestID)

	assert.Equal(t, 500, w.Code)

	var response APIResponse
	err := json.Unmarshal(w.Body.Bytes(), &response)
	assert.NoError(t, err)
	assert.False(t, response.Success)
	assert.Equal(t, response.Error, "Internal server error")
	assert.Equal(t, response.Message, "runtime error: integer divide by zero")
	assert.NotEmpty(t, response.RequestID)
}

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// -----------------------------------------------------------------
// Test Rate Limiting Middleware
//
// -- IMPORTANT --
// The following test must be the last one otherwise it will
// cause rate limit problem to all other tests because it will
// consume all available tokens and reach the rate limit.
// -----------------------------------------------------------------

func TestRateLimitMiddleware(t *testing.T) {
	router := setupRouter()

	// NOTE: Description of the rate limiter to implement
	// Limit: 100 requests per IP per minute
	// Set headers: X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset
	// Return 429 if rate limit exceeded

	var limit, remain, reset int = 0, 0, 0
	var err error

	// Do a first request to capture the remaining token value
	w := httptest.NewRecorder()
	req, _ := http.NewRequest("GET", "/ping", nil)
	router.ServeHTTP(w, req)

	assert.Equal(t, 200, w.Code)
	limitStr := w.Header().Get("X-RateLimit-Limit")
	limit, err = strconv.Atoi(limitStr)
	assert.NoError(t, err)
	assert.Equal(t, 100, limit)

	remainStr := w.Header().Get("X-RateLimit-Remaining")
	remain, err = strconv.Atoi(remainStr)
	assert.NoError(t, err)
	assert.Greater(t, remain, 0)

	resetStr := w.Header().Get("X-RateLimit-Reset")
	reset, err = strconv.Atoi(resetStr)
	assert.NoError(t, err)
	assert.Greater(t, reset, int(time.Now().Unix()))

	limitIndex := remain

	for i := 1; i < 102; i++ {
		w = httptest.NewRecorder()
		req, _ = http.NewRequest("GET", "/ping", nil)
		router.ServeHTTP(w, req)

		limitStr = w.Header().Get("X-RateLimit-Limit")
		limit, err = strconv.Atoi(limitStr)
		assert.NoError(t, err)
		assert.Equal(t, 100, limit)

		remainStr = w.Header().Get("X-RateLimit-Remaining")
		remain, err = strconv.Atoi(remainStr)
		assert.NoError(t, err)

		resetStr = w.Header().Get("X-RateLimit-Reset")
		reset, err = strconv.Atoi(resetStr)
		assert.NoError(t, err)
		assert.Greater(t, reset, int(time.Now().Unix()))

		// Allowed requests should succeed (with remain > 0)
		if i < limitIndex {
			assert.Equal(t, w.Code, 200)
			assert.Greater(t, remain, 0)
		}

		// Last allowed request should succeed (with remain == 0)
		if i == limitIndex {
			assert.Equal(t, w.Code, 200)
			assert.Equal(t, remain, 0)
		}

		// All Requests over the rate limit should fail
		if i > limitIndex {
			assert.Equal(t, w.Code, 429)
			assert.Equal(t, remain, 0)
		}
	}
}

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NOTE: My solution to Gin Challenge 2 is passing those tests.