增加 Code 函数获取 error 对应的 code

Author: FishGoddess

HISTORY.md

@@ -1,5 +1,11 @@
 ## ✒ 历史版本的特性介绍 (Features in old versions)
 
+### v0.3.0
+
+> 此版本发布于 2023-06-18
+
+* 增加 Code 函数获取 error 对应的 code
+
 ### v0.2.1
 
 > 此版本发布于 2023-04-24

README.en.md

@@ -61,6 +61,7 @@ func main() {
 	// Use WithMsg to carry a message.
 	err = errors.Wrap(io.EOF, codeTestError, errors.WithMsg("test"))
 	fmt.Println(err.Error())
+	fmt.Println(errors.Code(err))
 	fmt.Println(errors.Msg(err))
 }
 ```

README.md

@@ -61,6 +61,7 @@ func main() {
 	// Use WithMsg to carry a message.
 	err = errors.Wrap(io.EOF, codeTestError, errors.WithMsg("test"))
 	fmt.Println(err.Error())
+	fmt.Println(errors.Code(err))
 	fmt.Println(errors.Msg(err))
 }
 ```

_examples/basic.go

@@ -47,5 +47,6 @@ func main() {
 	// Use WithMsg to carry a message.
 	err = errors.Wrap(io.EOF, codeTestError, errors.WithMsg("test"))
 	fmt.Println(err.Error())
+	fmt.Println(errors.Code(err))
 	fmt.Println(errors.Msg(err))
 }

_icons/coverage.svg

@@ -9,6 +9,11 @@ import (
 	"fmt"
 )
 
+const (
+	codeNil     = 0
+	codeUnknown = 1
+)
+
 const (
 	nilString = "<nil>"
 )
@@ -114,6 +119,20 @@ func Is(err error, code int32) bool {
 	return ok
 }
 
+// Code returns the code of err.
+func Code(err error) int32 {
+	if err == nil {
+		return codeNil
+	}
+
+	e, ok := err.(*Error)
+	if !ok {
+		return codeUnknown
+	}
+
+	return e.code
+}
+
 // Msg returns the msg of err.
 func Msg(err error) string {
 	if err == nil {

errors.go

@@ -6,6 +6,7 @@ package errors
 
 import (
 	"errors"
+	"io"
 	"testing"
 )
 
@@ -24,6 +25,31 @@ func TestError(t *testing.T) {
 	}
 }
 
+// go test -v -cover -run=^TestCode$
+func TestCode(t *testing.T) {
+	code := int32(500)
+
+	got := Code(nil)
+	if got != codeNil {
+		t.Errorf("got %d is wrong", got)
+	}
+
+	got = Code(Wrap(nil, code))
+	if got != codeNil {
+		t.Errorf("got %d is wrong", got)
+	}
+
+	got = Code(io.EOF)
+	if got != codeUnknown {
+		t.Errorf("got %d is wrong", got)
+	}
+
+	got = Code(Wrap(errors.New("500"), code))
+	if got != code {
+		t.Errorf("got %d is wrong", got)
+	}
+}
+
 // go test -v -cover -run=^TestMsg$
 func TestMsg(t *testing.T) {
 	code := int32(500)