package union import (	"errors"	"testing" 	"github.com/stretchr/testify/assert") var (	err1 = errors.New("Error 1")	err2 = errors.New("Error 2")	err3 = errors.New("Error 3")) func TestErrorsMap(t *testing.T) {	es := Errors{		nil,		err1,		err2,	}	want := Errors{		err2,	}	got := es.Map(func(e error) error {		if e == err1 {			return nil		}		return e	})	assert.Equal(t, want, got)} func TestErrorsFilterNil(t *testing.T) {	es := Errors{		nil,		err1,		nil,		err2,		nil,	}	want := Errors{		err1,		err2,	}	got := es.FilterNil()	assert.Equal(t, want, got)} func TestErrorsErr(t *testing.T) {	// Check not all nil case	es := Errors{		nil,		err1,		nil,		err2,		nil,	}	want := Errors{		err1,		err2,	}	got := es.Err() 	// Check all nil case	assert.Equal(t, want, got)	es = Errors{		nil,		nil,		nil,	}	assert.Nil(t, es.Err())} func TestErrorsError(t *testing.T) {	assert.Equal(t, "no error", Errors{}.Error())	assert.Equal(t, "1 error: Error 1", Errors{err1}.Error())	assert.Equal(t, "1 error: nil error", Errors{nil}.Error())	assert.Equal(t, "2 errors: Error 1; Error 2", Errors{err1, err2}.Error())} func TestErrorsUnwrap(t *testing.T) {	es := Errors{		err1,		err2,	}	assert.Equal(t, []error{err1, err2}, es.Unwrap())	assert.True(t, errors.Is(es, err1))	assert.True(t, errors.Is(es, err2))	assert.False(t, errors.Is(es, err3))}