limiter middleware new options: SkipFailedRequests, SkipSuccessfulRequests (#1542)

middleware/limiter/README.md

@@ -109,6 +109,16 @@ type Config struct {
 	// }
 	LimitReached fiber.Handler
 
+	// When set to true, requests with StatusCode >= 400 won't be counted.
+	//
+	// Default: false
+	SkipFailedRequests bool
+
+	// When set to true, requests with StatusCode < 400 won't be counted.
+	//
+	// Default: false
+	SkipSuccessfulRequests bool
+
 	// Store is used to store the state of the middleware
 	//
 	// Default: an in memory store for this process only
@@ -130,5 +140,7 @@ var ConfigDefault = Config{
 	LimitReached: func(c *fiber.Ctx) error {
 		return c.SendStatus(fiber.StatusTooManyRequests)
 	},
+	SkipFailedRequests: false,
+	SkipSuccessfulRequests: false,
 }
 ```

middleware/limiter/config.go

@@ -38,6 +38,16 @@ type Config struct {
 	// }
 	LimitReached fiber.Handler
 
+	// When set to true, requests with StatusCode >= 400 won't be counted.
+	//
+	// Default: false
+	SkipFailedRequests bool
+
+	// When set to true, requests with StatusCode < 400 won't be counted.
+	//
+	// Default: false
+	SkipSuccessfulRequests bool
+
 	// Store is used to store the state of the middleware
 	//
 	// Default: an in memory store for this process only
@@ -63,6 +73,8 @@ var ConfigDefault = Config{
 	LimitReached: func(c *fiber.Ctx) error {
 		return c.SendStatus(fiber.StatusTooManyRequests)
 	},
+	SkipFailedRequests:     false,
+	SkipSuccessfulRequests: false,
 }
 
 // Helper function to set default values

middleware/limiter/limiter.go

@@ -50,6 +50,10 @@ func New(config ...Config) fiber.Handler {
 			return c.Next()
 		}
 
+		// Continue stack for reaching c.Response().StatusCode()
+		// Store err for returning
+		err := c.Next()
+
 		// Get key from request
 		key := cfg.KeyGenerator(c)
 
@@ -72,8 +76,12 @@ func New(config ...Config) fiber.Handler {
 			e.exp = ts + expiration
 		}
 
-		// Increment hits
+		// Check for SkipFailedRequests and SkipSuccessfulRequests
-		e.hits++
+		if (!cfg.SkipSuccessfulRequests || c.Response().StatusCode() >= 400) &&
+			(!cfg.SkipFailedRequests || c.Response().StatusCode() < 400) {
+			// Increment hits
+			e.hits++
+		}
 
 		// Calculate when it resets in seconds
 		expire := e.exp - ts
@@ -102,7 +110,6 @@ func New(config ...Config) fiber.Handler {
 		c.Set(xRateLimitRemaining, strconv.Itoa(remaining))
 		c.Set(xRateLimitReset, strconv.FormatUint(expire, 10))
 
-		// Continue stack
+		return err
-		return c.Next()
 	}
 }

middleware/limiter/limiter_test.go

@@ -14,7 +14,7 @@ import (
 	"github.com/valyala/fasthttp"
 )
 
-// go test -run Test_Limiter_Concurrency -race -v
+// go test -run Test_Limiter_Concurrency_Store -race -v
 func Test_Limiter_Concurrency_Store(t *testing.T) {
 	// Test concurrency using a custom store
 
@@ -107,6 +107,84 @@ func Test_Limiter_Concurrency(t *testing.T) {
 
 }
 
+// go test -run Test_Limiter_Skip_Failed_Requests -v
+func Test_Limiter_Skip_Failed_Requests(t *testing.T) {
+
+	app := fiber.New()
+
+	app.Use(New(Config{
+		Max:                1,
+		Expiration:         2 * time.Second,
+		SkipFailedRequests: true,
+	}))
+
+	app.Get("/:status", func(c *fiber.Ctx) error {
+		if c.Params("status") == "fail" {
+			return c.SendStatus(400)
+		}
+		return c.SendStatus(200)
+	})
+
+	resp, err := app.Test(httptest.NewRequest(http.MethodGet, "/fail", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 400, resp.StatusCode)
+
+	resp, err = app.Test(httptest.NewRequest(http.MethodGet, "/success", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 200, resp.StatusCode)
+
+	resp, err = app.Test(httptest.NewRequest(http.MethodGet, "/success", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 429, resp.StatusCode)
+
+	time.Sleep(3 * time.Second)
+
+	resp, err = app.Test(httptest.NewRequest(http.MethodGet, "/success", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 200, resp.StatusCode)
+
+}
+
+// go test -run Test_Limiter_Skip_Successful_Requests -v
+func Test_Limiter_Skip_Successful_Requests(t *testing.T) {
+
+	// Test concurrency using a default store
+
+	app := fiber.New()
+
+	app.Use(New(Config{
+		Max:                    1,
+		Expiration:             2 * time.Second,
+		SkipSuccessfulRequests: true,
+	}))
+
+	app.Get("/:status", func(c *fiber.Ctx) error {
+		if c.Params("status") == "fail" {
+			return c.SendStatus(400)
+		}
+		return c.SendStatus(200)
+	})
+
+	resp, err := app.Test(httptest.NewRequest(http.MethodGet, "/success", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 200, resp.StatusCode)
+
+	resp, err = app.Test(httptest.NewRequest(http.MethodGet, "/fail", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 400, resp.StatusCode)
+
+	resp, err = app.Test(httptest.NewRequest(http.MethodGet, "/fail", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 429, resp.StatusCode)
+
+	time.Sleep(3 * time.Second)
+
+	resp, err = app.Test(httptest.NewRequest(http.MethodGet, "/fail", nil))
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, 400, resp.StatusCode)
+
+}
+
 // go test -v -run=^$ -bench=Benchmark_Limiter_Custom_Store -benchmem -count=4
 func Benchmark_Limiter_Custom_Store(b *testing.B) {
 	app := fiber.New()