#98 Bug/incorrect response code for empty body

handler.go

@@ -89,6 +89,10 @@ func (g *gzipHandler) Handle(c *gin.Context) {
 		if c.Writer.Size() < 0 {
 			// do not write gzip footer when nothing is written to the response body
 			gz.Reset(io.Discard)
+
+			// revert back to the original gin ResponseWriter to allow gin to handle the empty response (i.e. 404)
+			c.Writer = c.Writer.(*gzipWriter).ResponseWriter
+			c.Header(headerContentEncoding, "")
 		}
 		_ = gz.Close()
 		if c.Writer.Size() > -1 {

handler_test.go

@@ -22,20 +22,39 @@ func TestHandleGzip(t *testing.T) {
 		acceptEncoding          string
 		expectedContentEncoding string
 		expectedBody            string
+		expectedStatus          int
 	}{
 		{
 			name:                    "Gzip compression",
 			path:                    "/",
 			acceptEncoding:          "gzip",
 			expectedContentEncoding: "gzip",
 			expectedBody:            "Gzip Test Response",
+			expectedStatus:          http.StatusOK,
 		},
 		{
 			name:                    "No compression",
 			path:                    "/",
 			acceptEncoding:          "",
 			expectedContentEncoding: "",
 			expectedBody:            "Gzip Test Response",
+			expectedStatus:          http.StatusOK,
+		},
+		{
+			name:                    "Bad path, no compression",
+			path:                    "/bad-path",
+			acceptEncoding:          "",
+			expectedContentEncoding: "",
+			expectedBody:            "404 page not found",
+			expectedStatus:          http.StatusNotFound,
+		},
+		{
+			name:                    "Bad path, with compression",
+			path:                    "/bad-path",
+			acceptEncoding:          "gzip",
+			expectedContentEncoding: "",
+			expectedBody:            "404 page not found",
+			expectedStatus:          http.StatusNotFound,
 		},
 	}
 
@@ -53,7 +72,7 @@ func TestHandleGzip(t *testing.T) {
 			w := httptest.NewRecorder()
 			router.ServeHTTP(w, req)
 
-			assert.Equal(t, http.StatusOK, w.Code)
+			assert.Equal(t, tt.expectedStatus, w.Code)
 			assert.Equal(t, tt.expectedContentEncoding, w.Header().Get("Content-Encoding"))
 
 			if tt.expectedContentEncoding == "gzip" {