removed Is method and improved StatusCode method

Author: suwakei

httperror.go

@@ -73,18 +73,14 @@ func (he *HTTPError) Error() string {
 	return fmt.Sprintf("code=%d, message=%v, err=%v", he.Code, msg, he.err.Error())
 }
 
-// Is checks if this error is equal to the target error.
-func (he *HTTPError) Is(target error) bool {
-	if he == target {
-		return true
+// HTTPStatusCode returns status code from error if it implements HTTPStatusCoder interface.
+// If error does not implement the interface it returns 0.
+func HTTPStatusCode(err error) int {
+	var sc HTTPStatusCoder
+	if errors.As(err, &sc) {
+		return sc.StatusCode()
 	}
-	switch t := target.(type) {
-	case *HTTPError:
-		return he.Code == t.Code
-	case *httpError:
-		return he.Code == t.code
-	}
-	return false
+	return 0
 }
 
 // Wrap eturns new HTTPError with given errors wrapped inside

httperror_test.go

@@ -5,9 +5,11 @@ package echo
 
 import (
 	"errors"
-	"github.com/stretchr/testify/assert"
+	"fmt"
 	"net/http"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestHTTPError_StatusCode(t *testing.T) {
@@ -66,54 +68,42 @@ func TestNewHTTPError(t *testing.T) {
 	assert.Equal(t, err2, err)
 }
 
-func TestHTTPError_Is(t *testing.T) {
+func TestHTTPStatusCode(t *testing.T) {
 	var testCases = []struct {
 		name   string
-		err    *HTTPError
-		target error
-		expect bool
+		err    error
+		expect int
 	}{
 		{
-			name:   "ok, same instance",
-			err:    &HTTPError{Code: http.StatusNotFound},
-			target: &HTTPError{Code: http.StatusNotFound},
-			expect: true,
-		},
-		{
-			name:   "ok, different instance, same code",
+			name:   "ok, HTTPError",
 			err:    &HTTPError{Code: http.StatusNotFound},
-			target: &HTTPError{Code: http.StatusNotFound, Message: "different"},
-			expect: true,
+			expect: http.StatusNotFound,
 		},
 		{
-			name:   "ok, target is sentinel error",
-			err:    &HTTPError{Code: http.StatusNotFound},
-			target: ErrNotFound,
-			expect: true,
+			name:   "ok, sentinel error",
+			err:    ErrNotFound,
+			expect: http.StatusNotFound,
 		},
 		{
-			name:   "nok, different code",
-			err:    &HTTPError{Code: http.StatusNotFound},
-			target: &HTTPError{Code: http.StatusInternalServerError},
-			expect: false,
+			name:   "ok, wrapped HTTPError",
+			err:    fmt.Errorf("wrapped: %w", &HTTPError{Code: http.StatusTeapot}),
+			expect: http.StatusTeapot,
 		},
 		{
-			name:   "nok, target is sentinel error with different code",
-			err:    &HTTPError{Code: http.StatusNotFound},
-			target: ErrInternalServerError,
-			expect: false,
+			name:   "nok, normal error",
+			err:    errors.New("error"),
+			expect: 0,
 		},
 		{
-			name:   "nok, target is different error type",
-			err:    &HTTPError{Code: http.StatusNotFound},
-			target: errors.New("some error"),
-			expect: false,
+			name:   "nok, nil",
+			err:    nil,
+			expect: 0,
 		},
 	}
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			assert.Equal(t, tc.expect, errors.Is(tc.err, tc.target))
+			assert.Equal(t, tc.expect, HTTPStatusCode(tc.err))
 		})
 	}
 }