package main

import (
	"bytes"
	"strings"
	"testing"
)

func TestParse(t *testing.T) {
	const input = `From user1

Body 1

From user2

Body 2 with From in it.

From user3

Body 3
`
	wants := []string{
		`From user1

Body 1
`,
		`From user2

Body 2 with From in it.
`,
		`From user3

Body 3
`,
	}
	msgN := 0
	testWriteMessage := func(got []byte) error {
		want := wants[msgN]
		if !bytes.Equal([]byte(want), got) {
			t.Errorf("msg[%d] = %q, want %q", msgN, got, want)
		}
		msgN++
		return nil
	}
	if err := parse(strings.NewReader(input), testWriteMessage); err != nil {
		t.Errorf("parse() failed: %v", err)
	}
	if msgN != len(wants) {
		t.Errorf("Parsed %d messages, expected %d", msgN, len(wants))
	}
}