package hatmill_test

import (
	"bytes"
	"github.com/leanovate/gopter"
	"github.com/leanovate/gopter/gen"
	"github.com/leanovate/gopter/prop"
	"gitlab.codemonkeysoftware.com/b/hatmill"
	"testing"
)

type NopWriter struct{}

func (NopWriter) Write(p []byte) (n int, err error) {
	return len(p), nil
}

func TestText(t *testing.T) {
	properties := gopter.NewProperties(nil)

	properties.Property("writing to string is identity", prop.ForAll(
		func(s string) bool {
			var buf bytes.Buffer
			hatmill.Text(s).WriteTo(&buf)
			return buf.String() == s
		},
		gen.AnyString(),
	))

	properties.Property("WriteTo returns correct n", prop.ForAll(
		func(s string) bool {
			n, _ := hatmill.Text(s).WriteTo(NopWriter{})
			return n == int64(len(s))
		},
		gen.AnyString(),
	))

	properties.Property("WriteTo does not generate error", prop.ForAll(
		func(s string) bool {
			_, err := hatmill.Text(s).WriteTo(NopWriter{})
			return err == nil
		},
		gen.AnyString(),
	))

	properties.TestingRun(t)
}