Fix cannot process array of values in `application/x-www-form-urlenco…

…ded` request (gofiber#1873)

* Renamed parseQuery to parseParamSquareBrackets

* Added square brackets processing for `application/x-www-form-urlencoded`

* Added test cases for Array of form values

ctx.go

@@ -341,10 +341,20 @@ func (c *Ctx) BodyParser(out interface{}) error {
 	}
 	if strings.HasPrefix(ctype, MIMEApplicationForm) {
 		data := make(map[string][]string)
+		var err error
+
 		c.fasthttp.PostArgs().VisitAll(func(key, val []byte) {
+			if err != nil {
+				return
+			}
+
 			k := utils.UnsafeString(key)
 			v := utils.UnsafeString(val)
 
+			if strings.Contains(k, "[") {
+				k, err = parseParamSquareBrackets(k)
+			}
+
 			if strings.Contains(v, ",") && equalFieldType(out, reflect.Slice, k) {
 				values := strings.Split(v, ",")
 				for i := 0; i < len(values); i++ {
@@ -929,7 +939,7 @@ func (c *Ctx) QueryParser(out interface{}) error {
 		v := utils.UnsafeString(val)
 
 		if strings.Contains(k, "[") {
-			k, err = parseQuery(k)
+			k, err = parseParamSquareBrackets(k)
 		}
 
 		if strings.Contains(v, ",") && equalFieldType(out, reflect.Slice, k) {
@@ -950,7 +960,7 @@ func (c *Ctx) QueryParser(out interface{}) error {
 	return c.parseToStruct(queryTag, out, data)
 }
 
-func parseQuery(k string) (string, error) {
+func parseParamSquareBrackets(k string) (string, error) {
 	bb := bytebufferpool.Get()
 	defer bytebufferpool.Put(bb)
 

ctx_test.go

@@ -399,6 +399,30 @@ func Test_Ctx_BodyParser(t *testing.T) {
 
 	testDecodeParserError("invalid-content-type", "")
 	testDecodeParserError(MIMEMultipartForm+`;boundary="b"`, "--b")
+
+	type CollectionQuery struct {
+		Data []Demo `query:"data"`
+	}
+
+	c.Request().Reset()
+	c.Request().Header.SetContentType(MIMEApplicationForm)
+	c.Request().SetBody([]byte("data[0][name]=john&data[1][name]=doe"))
+	c.Request().Header.SetContentLength(len(c.Body()))
+	cq := new(CollectionQuery)
+	utils.AssertEqual(t, nil, c.BodyParser(cq))
+	utils.AssertEqual(t, 2, len(cq.Data))
+	utils.AssertEqual(t, "john", cq.Data[0].Name)
+	utils.AssertEqual(t, "doe", cq.Data[1].Name)
+
+	c.Request().Reset()
+	c.Request().Header.SetContentType(MIMEApplicationForm)
+	c.Request().SetBody([]byte("data.0.name=john&data.1.name=doe"))
+	c.Request().Header.SetContentLength(len(c.Body()))
+	cq = new(CollectionQuery)
+	utils.AssertEqual(t, nil, c.BodyParser(cq))
+	utils.AssertEqual(t, 2, len(cq.Data))
+	utils.AssertEqual(t, "john", cq.Data[0].Name)
+	utils.AssertEqual(t, "doe", cq.Data[1].Name)
 }
 
 // go test -run Test_Ctx_BodyParser_WithSetParserDecoder