go-spew/spew/internal_test.go

82 lines
2.3 KiB
Go

/*
* Copyright (c) 2013 Dave Collins <dave@davec.name>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
This test file is part of the spew package rather than than the spew_test
package because it needs access to internals to properly test certain cases
which are not possible via the public interface since they should never happen.
*/
package spew
import (
"bytes"
"reflect"
"testing"
)
// dummyFmtState implements a fake fmt.State to use for testing invalid
// reflect.Value handling. This is necessary because the fmt package catches
// invalid values before invoking the formatter on them.
type dummyFmtState struct {
bytes.Buffer
}
func (dfs *dummyFmtState) Flag(f int) bool {
if f == int('+') {
return true
}
return false
}
func (dfs *dummyFmtState) Precision() (int, bool) {
return 0, false
}
func (dfs *dummyFmtState) Width() (int, bool) {
return 0, false
}
// TestInvalidReflectValue ensures the dump and formatter code handles an
// invalid reflect value properly. This needs access to internal state since it
// should never happen in real code and therefore can't be tested via the public
// API.
func TestInvalidReflectValue(t *testing.T) {
i := 1
// Dump invalid reflect value.
v := new(reflect.Value)
buf := new(bytes.Buffer)
d := dumpState{w: buf, cs: &Config}
d.dump(*v)
s := buf.String()
want := "<invalid>"
if s != want {
t.Errorf("InvalidReflectValue #%d\n got: %s want: %s", i, s, want)
}
i++
// Formatter invalid reflect value.
buf2 := new(dummyFmtState)
f := formatState{value: *v, cs: &Config, fs: buf2}
f.format(*v)
s = buf2.String()
want = "<invalid>"
if s != want {
t.Errorf("InvalidReflectValue #%d got: %s want: %s", i, s, want)
}
}