func TestCause(t *testing.T) {
if cause := errors.Cause(someErr); cause != someErr {
t.Fatalf("expected %q kind; got %#v", someErr, cause)
}
causeErr := errors.New("cause error")
underlyingErr := errors.New("underlying error") //err TestCause#1
err := errors.WithCausef(underlyingErr, causeErr, "foo %d", 99) //err TestCause#2
if errors.Cause(err) != causeErr {
t.Fatalf("expected %q; got %#v", causeErr, errors.Cause(err))
}
checkErr(t, err, underlyingErr, "foo 99: underlying error", "[{$TestCause#2$: foo 99} {$TestCause#1$: underlying error}]", causeErr)
err = &embed{err.(*errors.Err)}
if errors.Cause(err) != causeErr {
t.Fatalf("expected %q; got %#v", causeErr, errors.Cause(err))
}
}
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)
}
}
func TestMaskFunc(t *testing.T) {
err0 := errors.New("zero")
err1 := errors.New("one")
allowVals := func(vals ...error) (r []func(error) bool) {
for _, val := range vals {
r = append(r, errors.Is(val))
}
return
}
tests := []struct {
err error
allow0 []func(error) bool
allow1 []func(error) bool
cause error
}{{
err: err0,
allow0: allowVals(err0),
cause: err0,
}, {
err: err1,
allow0: allowVals(err0),
cause: nil,
}, {
err: err0,
allow1: allowVals(err0),
cause: err0,
}, {
err: err0,
allow0: allowVals(err1),
allow1: allowVals(err0),
cause: err0,
}, {
err: err0,
allow0: allowVals(err0, err1),
cause: err0,
}, {
err: err1,
allow0: allowVals(err0, err1),
cause: err1,
}, {
err: err0,
allow1: allowVals(err0, err1),
cause: err0,
}, {
err: err1,
allow1: allowVals(err0, err1),
cause: err1,
}}
for i, test := range tests {
wrap := errors.MaskFunc(test.allow0...)
err := wrap(test.err, test.allow1...)
cause := errors.Cause(err)
wantCause := test.cause
if wantCause == nil {
wantCause = err
}
if cause != wantCause {
t.Errorf("test %d. got %#v want %#v", i, cause, err)
}
}
}