feat: support std errors functions

go113.go

@@ -0,0 +1,13 @@
+// +build go1.13
+
+package errors
+
+import (
+	stderrors "errors"
+)
+
+func Is(err, target error) bool { return stderrors.Is(err, target) }
+
+func As(err error, target interface{}) bool { return stderrors.As(err, target) }
+
+func Unwrap(err error) error { return stderrors.Unwrap(err) }

go113_test.go

@@ -3,14 +3,154 @@
 package errors
 
 import (
-	stdlib_errors "errors"
+	stderrors "errors"
+	"reflect"
 	"testing"
 )
 
 func TestErrorChainCompat(t *testing.T) {
-	err := stdlib_errors.New("error that gets wrapped")
+	err := stderrors.New("error that gets wrapped")
 	wrapped := Wrap(err, "wrapped up")
-	if !stdlib_errors.Is(wrapped, err) {
+	if !stderrors.Is(wrapped, err) {
 		t.Errorf("Wrap does not support Go 1.13 error chains")
 	}
 }
+
+func TestIs(t *testing.T) {
+	err := New("test")
+
+	type args struct {
+		err    error
+		target error
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			name: "with stack",
+			args: args{
+				err:    WithStack(err),
+				target: err,
+			},
+			want: true,
+		},
+		{
+			name: "with message",
+			args: args{
+				err:    WithMessage(err, "test"),
+				target: err,
+			},
+			want: true,
+		},
+		{
+			name: "with message format",
+			args: args{
+				err:    WithMessagef(err, "%s", "test"),
+				target: err,
+			},
+			want: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := Is(tt.args.err, tt.args.target); got != tt.want {
+				t.Errorf("Is() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+type customErr struct {
+	msg string
+}
+
+func (c customErr) Error() string { return c.msg }
+
+func TestAs(t *testing.T) {
+	var err = customErr{msg: "test message"}
+
+	type args struct {
+		err    error
+		target interface{}
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			name: "with stack",
+			args: args{
+				err:    WithStack(err),
+				target: new(customErr),
+			},
+			want: true,
+		},
+		{
+			name: "with message",
+			args: args{
+				err:    WithMessage(err, "test"),
+				target: new(customErr),
+			},
+			want: true,
+		},
+		{
+			name: "with message format",
+			args: args{
+				err:    WithMessagef(err, "%s", "test"),
+				target: new(customErr),
+			},
+			want: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := As(tt.args.err, tt.args.target); got != tt.want {
+				t.Errorf("As() = %v, want %v", got, tt.want)
+			}
+
+			ce := tt.args.target.(*customErr)
+			if !reflect.DeepEqual(err, *ce) {
+				t.Errorf("set target error failed, target error is %v", *ce)
+			}
+		})
+	}
+}
+
+func TestUnwrap(t *testing.T) {
+	err := New("test")
+
+	type args struct {
+		err error
+	}
+	tests := []struct {
+		name string
+		args args
+		want error
+	}{
+		{
+			name: "with stack",
+			args: args{err: WithStack(err)},
+			want: err,
+		},
+		{
+			name: "with message",
+			args: args{err: WithMessage(err, "test")},
+			want: err,
+		},
+		{
+			name: "with message format",
+			args: args{err: WithMessagef(err, "%s", "test")},
+			want: err,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := Unwrap(tt.args.err); !reflect.DeepEqual(err, tt.want) {
+				t.Errorf("Unwrap() error = %v, want %v", err, tt.want)
+			}
+		})
+	}
+}