func TestDetails(t *testing.T) {
if details := errors.Details(nil); details != "[]" {
t.Fatalf("errors.Details(nil) got %q want %q", details, "[]")
}
otherErr := fmt.Errorf("other")
checkErr(t, otherErr, nil, "other", "[{other}]", otherErr)
err0 := &embed{errors.New("foo").(*errors.Err)} //err TestStack#0
checkErr(t, err0, nil, "foo", "[{$TestStack#0$: foo}]", err0)
err1 := &embed{errors.Notef(err0, "bar").(*errors.Err)} //err TestStack#1
checkErr(t, err1, err0, "bar: foo", "[{$TestStack#1$: bar} {$TestStack#0$: foo}]", err1)
err2 := errors.Mask(err1) //err TestStack#2
checkErr(t, err2, err1, "bar: foo", "[{$TestStack#2$: } {$TestStack#1$: bar} {$TestStack#0$: foo}]", err2)
}
func checkErr(t *testing.T, err, underlying error, msg string, details string, cause error) {
if err == nil {
t.Fatalf("err is nil; want %q", msg)
}
if err.Error() != msg {
t.Fatalf("unexpected message: want %q; got %q", msg, err.Error())
}
if err, ok := err.(errors.Wrapper); ok {
if err.Underlying() != underlying {
t.Fatalf("unexpected underlying error: want %q; got %v", underlying, err.Underlying())
}
} else if underlying != nil {
t.Fatalf("no underlying error found; want %q", underlying)
}
if errors.Cause(err) != cause {
t.Fatalf("unexpected cause: want %#v; got %#v", cause, errors.Cause(err))
}
wantDetails := replaceLocations(details)
if gotDetails := errors.Details(err); gotDetails != wantDetails {
t.Fatalf("unexpected details: want %q; got %q", wantDetails, gotDetails)
}
}