wrapper_test.go

package xerrors

import (
	"errors"
	"fmt"
	"io"
	"reflect"
	"testing"
)

func TestWithWrapper(t *testing.T) {
	tests := []struct {
		wrapper error
		err     error
		msg     string
		want    string
	}{
		{wrapper: Message("wrapper"), err: Message("err"), want: "wrapper: err"},
		{wrapper: Message("wrapper"), err: io.EOF, want: "wrapper: EOF"},
		{wrapper: nil, err: Message("err"), want: "err"},
		{wrapper: Message("wrapper"), err: Message("err"), msg: "msg", want: "msg"},
	}
	for n, tt := range tests {
		t.Run(fmt.Sprintf("case-%d", n+1), func(t *testing.T) {
			got := &withWrapper{
				wrapper: tt.wrapper,
				err:     tt.err,
				msg:     tt.msg,
			}
			if got.Error() != tt.want {
				t.Errorf("WithWrapper(%#v, %#v): got: %q, want %q", tt.wrapper, tt.err, got, tt.want)
			}
			if len(StackTrace(got)) != 0 {
				t.Errorf("WithWrapper(%#v, %#v): returned error must not contain a stack trace", tt.wrapper, tt.err)
			}
			if !errors.Is(got, tt.err) {
				t.Errorf("WithWrapper(%#v, %#v): errors.Is must return true for err", tt.wrapper, tt.err)
			}
			if tt.wrapper != nil && !errors.Is(got, tt.wrapper) {
				t.Errorf("WithWrapper(%#v, %#v): errors.Is must return true for wrapper", tt.wrapper, tt.err)
			}
			if tt.err != nil && !errors.As(got, reflect.New(reflect.TypeOf(tt.err)).Interface()) {
				t.Errorf("errors.As(WithWrapper(%#v, %#v), err): must return true for the err error type", tt.wrapper, tt.err)
			}
			if tt.wrapper != nil && !errors.As(got, reflect.New(reflect.TypeOf(tt.wrapper)).Interface()) {
				t.Errorf("errors.As(WithWrapper(%#v, %#v), err): must return true for the wrapper error type", tt.wrapper, tt.err)
			}
		})
	}
}