golangci(lint) : more linters (#2870)

.github/workflows/gin.yml

@@ -24,6 +24,7 @@ jobs:
           version: v1.42.1
           args: --verbose
   test:
+    needs: lint
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]

.golangci.yml

@@ -2,9 +2,22 @@ run:
   timeout: 5m
 linters:
   enable:
+  - asciicheck
+  - depguard
+  - dogsled
+  - durationcheck
+  - errcheck
+  - errorlint
+  - exportloopref
+  - gci 
   - gofmt
+  - goimports
   - misspell
+  - nakedret
+  - nilerr
+  - nolintlint
   - revive
+  - wastedassign
 issues:
   exclude-rules:
   - linters:

binding/form.go

@@ -5,6 +5,7 @@
 package binding
 
 import (
+	"errors"
 	"net/http"
 )
 
@@ -22,7 +23,7 @@ func (formBinding) Bind(req *http.Request, obj interface{}) error {
 	if err := req.ParseForm(); err != nil {
 		return err
 	}
-	if err := req.ParseMultipartForm(defaultMemory); err != nil && err != http.ErrNotMultipart {
+	if err := req.ParseMultipartForm(defaultMemory); err != nil && !errors.Is(err, http.ErrNotMultipart) {
 		return err
 	}
 	if err := mapForm(obj, req.Form); err != nil {

context.go

@@ -220,7 +220,8 @@ func (c *Context) Error(err error) *Error {
 		panic("err is nil")
 	}
 
-	parsedError, ok := err.(*Error)
+	var parsedError *Error
+	ok := errors.As(err, &parsedError)
 	if !ok {
 		parsedError = &Error{
 			Err:  err,
@@ -515,7 +516,7 @@ func (c *Context) initFormCache() {
 		c.formCache = make(url.Values)
 		req := c.Request
 		if err := req.ParseMultipartForm(c.engine.MaxMultipartMemory); err != nil {
-			if err != http.ErrNotMultipart {
+			if !errors.Is(err, http.ErrNotMultipart) {
 				debugPrint("error on parse multipart form array: %v", err)
 			}
 		}

context_test.go

@@ -23,10 +23,9 @@ import (
 
 	"github.com/gin-contrib/sse"
 	"github.com/gin-gonic/gin/binding"
+	testdata "github.com/gin-gonic/gin/testdata/protoexample"
 	"github.com/stretchr/testify/assert"
 	"google.golang.org/protobuf/proto"
-
-	testdata "github.com/gin-gonic/gin/testdata/protoexample"
 )
 
 var _ context.Context = &Context{}

recovery.go

@@ -6,6 +6,7 @@ package gin
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -60,7 +61,8 @@ func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 				// condition that warrants a panic stack trace.
 				var brokenPipe bool
 				if ne, ok := err.(*net.OpError); ok {
-					if se, ok := ne.Err.(*os.SyscallError); ok {
+					var se *os.SyscallError
+					if errors.As(ne, &se) {
 						if strings.Contains(strings.ToLower(se.Error()), "broken pipe") || strings.Contains(strings.ToLower(se.Error()), "connection reset by peer") {
 							brokenPipe = true
 						}

render/render_test.go

@@ -14,10 +14,9 @@ import (
 	"strings"
 	"testing"
 
+	testdata "github.com/gin-gonic/gin/testdata/protoexample"
 	"github.com/stretchr/testify/assert"
 	"google.golang.org/protobuf/proto"
-
-	testdata "github.com/gin-gonic/gin/testdata/protoexample"
 )
 
 // TODO unit tests