Add ContentLength handler for checking the Content-Length HTTP header…

README.md

@@ -97,6 +97,14 @@ requests with no `Content-Type` header set.
 `ContentType` only acts on `POST`, `PATCH` and `PUT` requests, so it is safe to
 use it with `m.Use`. It will never block `GET` requests.
 
+#### The `strict.ContentLength` handler factory
+
+This handlers checks if the HTTP requests contain the `Content-Length` header.
+If the `Content-Length` header is not present, the handler returns a HTTP *411 Length Required*
+response.
+
+Like `ContentType` and `ContentCharset`, `ContentLength` only acts
+ on `POST`, `PATCH` and `PUT` requests.
 
 #### The `strict.ContentCharset` handler factory
 

strict.go

@@ -48,6 +48,16 @@ func ContentType(ctypes ...string) http.HandlerFunc {
 	}
 }
 
+// ContentLength generates a handler that writes a 411 Length Required response if the request
+// doesn't contain the Content-Length header
+func ContentLength() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if contentMethod(r.Method) && r.Header.Get("Content-Length") == "" {
+			w.WriteHeader(http.StatusLengthRequired)
+		}
+	}
+}
+
 // ContentCharset generates a handler that writes a 415 Unsupported Media Type response if none of the charsets match.
 // An empty charset will allow requests with no Content-Type header or no specified charset.
 func ContentCharset(charsets ...string) http.HandlerFunc {

strict_test.go

@@ -21,7 +21,7 @@ var _ = Describe("Negotiator", func() {
 		var err error
 		r, err = http.NewRequest("POST", "http://example.com/", nil)
 		Expect(err).
-			NotTo(HaveOccured())
+			NotTo(HaveOccurred())
 		n = &negotiator{r}
 	})
 	It("should parse the Accept header correctly", func() {
@@ -49,7 +49,7 @@ var _ = Describe("ContentType", func() {
 		var err error
 		r, err = http.NewRequest("POST", "http://example.com/", nil)
 		Expect(err).
-			NotTo(HaveOccured())
+			NotTo(HaveOccurred())
 		w = httptest.NewRecorder()
 	})
 	It("should accept requests with a matching content type", func() {
@@ -97,7 +97,7 @@ var _ = Describe("ContentType", func() {
 		for _, m := range []string{"POST", "PATCH", "PUT"} {
 			r, err = http.NewRequest(m, "http://example.com/", nil)
 			Expect(err).
-				NotTo(HaveOccured())
+				NotTo(HaveOccurred())
 			r.Header.Set("Content-Type", "text/plain")
 			ContentType("application/json", "text/xml", "")(w, r)
 			Expect(w.Code).
@@ -109,7 +109,7 @@ var _ = Describe("ContentType", func() {
 		for _, m := range []string{"GET", "HEAD", "OPTIONS", "DELETE"} {
 			r, err = http.NewRequest(m, "http://example.com/", nil)
 			Expect(err).
-				NotTo(HaveOccured())
+				NotTo(HaveOccurred())
 			r.Header.Set("Content-Type", "text/plain")
 			ContentType("application/json", "text/xml", "")(w, r)
 			Expect(w.Code).
@@ -118,14 +118,59 @@ var _ = Describe("ContentType", func() {
 	})
 })
 
+var _ = Describe("ContentLength", func() {
+	var w *httptest.ResponseRecorder
+	var r *http.Request
+	BeforeEach(func() {
+		var err error
+		r, err = http.NewRequest("POST", "http://example.com/", nil)
+		Expect(err).
+			NotTo(HaveOccurred())
+		w = httptest.NewRecorder()
+	})
+	It("should accept with Content-Length header set", func() {
+		r.Header.Set("Content-Length", "4")
+		ContentLength()(w, r)
+		Expect(w.Code).
+			ToNot(Equal(http.StatusLengthRequired))
+	})
+	It("should block requests with no Content-Length set", func() {
+		ContentLength()(w, r)
+		Expect(w.Code).
+			To(Equal(http.StatusLengthRequired))
+	})
+	It("should act on block POST, PATCH and PUT requests", func() {
+		var err error
+		for _, m := range []string{"POST", "PATCH", "PUT"} {
+			r, err = http.NewRequest(m, "http://example.com/", nil)
+			Expect(err).
+				NotTo(HaveOccurred())
+			ContentLength()(w, r)
+			Expect(w.Code).
+				To(Equal(http.StatusLengthRequired))
+		}
+	})
+	It("should not block GET, HEAD, OPTIONS and DELETE requests", func() {
+		var err error
+		for _, m := range []string{"GET", "HEAD", "OPTIONS", "DELETE"} {
+			r, err = http.NewRequest(m, "http://example.com/", nil)
+			Expect(err).
+				NotTo(HaveOccurred())
+			ContentLength()(w, r)
+			Expect(w.Code).
+				NotTo(Equal(http.StatusLengthRequired))
+		}
+	})
+})
+
 var _ = Describe("ContentCharset", func() {
 	var w *httptest.ResponseRecorder
 	var r *http.Request
 	BeforeEach(func() {
 		var err error
 		r, err = http.NewRequest("POST", "http://example.com/", nil)
 		Expect(err).
-			NotTo(HaveOccured())
+			NotTo(HaveOccurred())
 		w = httptest.NewRecorder()
 	})
 	It("should accept requests with a matching charset", func() {
@@ -181,7 +226,7 @@ var _ = Describe("ContentCharset", func() {
 		for _, m := range []string{"POST", "PATCH", "PUT"} {
 			r, err = http.NewRequest(m, "http://example.com/", nil)
 			Expect(err).
-				NotTo(HaveOccured())
+				NotTo(HaveOccurred())
 			r.Header.Set("Content-Type", "text/plain")
 			ContentType("application/json", "text/xml", "")(w, r)
 			Expect(w.Code).
@@ -193,7 +238,7 @@ var _ = Describe("ContentCharset", func() {
 		for _, m := range []string{"GET", "HEAD", "OPTIONS", "DELETE"} {
 			r, err = http.NewRequest(m, "http://example.com/", nil)
 			Expect(err).
-				NotTo(HaveOccured())
+				NotTo(HaveOccurred())
 			r.Header.Set("Content-Type", "text/plain")
 			ContentType("application/json", "text/xml", "")(w, r)
 			Expect(w.Code).
@@ -209,7 +254,7 @@ var _ = Describe("Accept", func() {
 		var err error
 		r, err = http.NewRequest("POST", "http://example.com/", nil)
 		Expect(err).
-			NotTo(HaveOccured())
+			NotTo(HaveOccurred())
 		w = httptest.NewRecorder()
 	})
 	It("should accept requests with a matching content type", func() {