// go test v1_test.go v1.go
package main

import (
	"errors"
	"testing"
)

func Equal(a, b error) bool {
	if a == nil {
		return b == nil
	}
	return b != nil && a.Error() == b.Error()
}

func TestLineCount(t *testing.T) {
	for i, tc := range []struct {
		path string
		lc   int
		err  error
	}{
		{"10", 10, nil},
		{"11", 0, errors.New("open 11: no such file or directory")},
	} {
		lc, err := lineCount(tc.path)
		if lc != tc.lc || !Equal(tc.err, err) {
			t.Errorf("%d. lineCount(%q) = %d, %s; want = %d, %s", i, tc.path, lc, err, tc.lc, tc.err)
		}
	}
}