* Excluding v9 validator instance because gin already have it

* Some code refactorings of validating errors processing
* Code cleaning
* Tests and lint
* Readme update

Author: smgladkovskiy

.gitignore

@@ -1,2 +1,5 @@
 .idea
-vendor
+vendor
+.golangci.yml
+c.out
+coverage.html

Makefile

@@ -0,0 +1,22 @@
+deps:
+	go mod vendor
+.PHONY: deps
+
+get_lint_config:
+	@[ -f ./.golangci.yml ] && echo ".golangci.yml exists" || ( echo "getting .golangci.yml" && curl -O https://raw.githubusercontent.com/microparts/docker-golang/master/lint/.golangci.yml )
+.PHONY: get_lint_config
+
+lint: get_lint_config
+	golangci-lint run
+.PHONY: lint
+
+test-unit:
+	go test $$(go list ./...) --race --cover -count=1 -timeout 1s -coverprofile=c.out -v
+.PHONY: test-unit
+
+coverage-html:
+	go tool cover -html=c.out -o coverage.html
+.PHONE: coverage-html
+
+test: deps test-unit coverage-html
+.PHONY: test

README.md

@@ -1,7 +1,8 @@
-errors-go-gin
--------------
+# ginerrors
 
-errors for gin
+Smart generating error code and response for gin mux based on passed error.
+
+## Usage
 
 ```go
 package main
@@ -16,10 +17,23 @@ import (
 )
 
 func main() {
-	ginerrors.InitValidator()
 	r := gin.New()
+
 	r.GET("/", func(c*gin.Context) {c.JSON(http.StatusOK,`{"status":"ok"}`)})
 	r.GET("/err", func(c *gin.Context) { ginerrors.Response(c, errors.New("error")) })
 	_ = r.Run(":8080")
 }
-```
+```
+
+## Linter
+
+Lint code with [golangci-lint](https://github.com/golangci/golangci-lint) and 
+[custom config](https://github.com/microparts/docker-golang/blob/master/lint/.golangci.yml) for it: 
+
+    make lint
+
+## Testing
+
+Test code with race checking and generation coverage profile:
+
+    make test

gin.go

@@ -2,14 +2,32 @@ package ginerrors
 
 import (
 	"database/sql"
+	"errors"
+	"fmt"
 	"net/http"
 	"strings"
 
 	"github.com/gin-gonic/gin"
-	"github.com/pkg/errors"
 	"gopkg.in/go-playground/validator.v9"
 )
 
+type langName string
+type validationRule string
+type errorPattern string
+type validationError map[validationRule]errorPattern
+
+func (ve errorPattern) string() string {
+	return string(ve)
+}
+
+var CommonValidationErrors = map[langName]validationError{
+	"ru": {
+		"ek":       "Ошибка валидации для свойства `%s` с правилом `%s`",
+		"required": "Свойство `%s` обязательно для заполнения",
+		"gt":       "Свойство `%s` должно содержать более `%s` элементов",
+	},
+}
+
 type ResponseObject struct {
 	Error ErrorObject `json:"error,omitempty"`
 }
@@ -22,6 +40,8 @@ type ErrorObject struct {
 }
 
 var (
+	defaultLang = "ru"
+
 	ErrNotFound       = errors.New("route not found")
 	ErrNoMethod       = errors.New("method not allowed")
 	ErrServerError    = errors.New("internal server error")
@@ -30,13 +50,22 @@ var (
 
 //Response makes common error response
 func Response(c *gin.Context, err interface{}) {
-	errCode, data := MakeResponse(err)
+	errCode, data := MakeResponse(err, getLang(c))
 	resp := ResponseObject{Error: *data}
 	c.AbortWithStatusJSON(errCode, resp)
 }
 
+func getLang(c *gin.Context) langName {
+	lang := c.GetHeader("lang")
+	if lang == "" {
+		lang = c.DefaultQuery("lang", defaultLang)
+	}
+
+	return langName(lang)
+}
+
 //MakeResponse makes ErrorObject based on error type
-func MakeResponse(err interface{}) (int, *ErrorObject) {
+func MakeResponse(err interface{}, lang langName) (int, *ErrorObject) {
 	errObj := &ErrorObject{}
 	errCode := http.StatusBadRequest
 
@@ -53,7 +82,7 @@ func MakeResponse(err interface{}) (int, *ErrorObject) {
 		errCode = http.StatusUnprocessableEntity
 
 		errObj.Message = "validation error"
-		errObj.Validation = MakeErrorsSlice(et)
+		errObj.Validation = MakeErrorsSlice(et, lang)
 
 	case error:
 		errCode, errObj.Message = getErrCode(et)
@@ -90,3 +119,45 @@ func getErrCode(et error) (errCode int, msg string) {
 
 	return
 }
+
+// validationErrors Формирование массива ошибок
+func MakeErrorsSlice(err error, lang langName) map[string][]string {
+	ve := map[string][]string{}
+	for _, e := range err.(validator.ValidationErrors) {
+		field := getFieldName(e.Namespace(), e.Field())
+		if _, ok := ve[field]; !ok {
+			ve[field] = []string{}
+		}
+		ve[field] = append(
+			ve[field],
+			getErrMessage(validationRule(e.ActualTag()), field, e.Param(), lang),
+		)
+	}
+	return ve
+}
+func getFieldName(namespace string, field string) string {
+	namespace = strings.Replace(namespace, "]", "", -1)
+	namespace = strings.Replace(namespace, "[", ".", -1)
+	namespaceSlice := strings.Split(namespace, ".")
+	fieldName := field
+
+	if len(namespaceSlice) > 2 {
+		fieldName = strings.Join([]string{strings.Join(namespaceSlice[1:len(namespaceSlice)-1], "."), field}, ".")
+	}
+
+	return fieldName
+}
+
+func getErrMessage(errorType validationRule, field string, param string, lang langName) string {
+	errKey := errorType
+	_, ok := CommonValidationErrors[lang][errorType]
+	if !ok {
+		errKey = "ek"
+	}
+
+	if param != "" && errKey == "ek" {
+		return fmt.Sprintf(CommonValidationErrors[lang][errKey].string(), field, errorType)
+	}
+
+	return fmt.Sprintf(CommonValidationErrors[lang][errKey].string(), field)
+}

gin_test.go

@@ -2,13 +2,13 @@ package ginerrors
 
 import (
 	"database/sql"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 
 	"github.com/gin-gonic/gin"
-	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"gopkg.in/go-playground/validator.v9"
 )
@@ -39,15 +39,14 @@ func TestMakeResponse(t *testing.T) {
 	}
 	for _, testCase := range cases {
 		t.Run(testCase.name, func(t *testing.T) {
-			errCode, errObject := MakeResponse(testCase.err)
+			errCode, errObject := MakeResponse(testCase.err, "ru")
 			assert.Equal(t, testCase.errObject, errObject, testCase.name)
 			assert.Equal(t, testCase.httpCode, errCode, testCase.name)
 		})
 	}
 }
 
 func setupRouter() *gin.Engine {
-	InitValidator()
 	r := gin.New()
 
 	r.NoRoute(func(c *gin.Context) { Response(c, ErrNotFound) })

gin_validator.go

@@ -4,7 +4,6 @@ go 1.12
 
 require (
 	github.com/gin-gonic/gin v1.4.1-0.20191002234641-4fd3234840db
-	github.com/pkg/errors v0.8.1
 	github.com/stretchr/testify v1.4.0
 	gopkg.in/go-playground/validator.v9 v9.30.0
 )

go.mod

@@ -22,8 +22,6 @@ github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 h1:ZqeYNhU3OH
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 h1:Esafd1046DLDQ0W1YjYsBW+p8U2u7vzgW2SQVmlNazg=
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
-github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
-github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=