go-by-test/blogposts/blogposts_test.go

package blogposts

import (
	"reflect"
	"testing"
	"testing/fstest"
)

// NOTE: This should be a black box test outside blogposts package.

// NOTE: If we want to test the return error
//
// type StubFailingFS struct{}
//
// func (s StubFailingFS) Open(name string) (fs.File, error) {
// 	return nil, errors.New("fail")
// }

func TestNewBlogPosts(t *testing.T) {
	fs := fstest.MapFS{
		"hello world.md":  {Data: []byte("Title: Post 1")},
		"hello-world2.md": {Data: []byte("Title: Post 2")},
	}

	posts, err := NewPostsFromFS(fs)
	if err != nil {
		t.Fatal(err)
	}

	if len(posts) != len(fs) {
		t.Errorf("got %d posts, wanted %d posts", len(posts), len(fs))
	}

	got := posts[0]
	want := Post{Title: "Post 1"}

	if !reflect.DeepEqual(got, want) {
		t.Errorf("got %+v, want %+v", got, want)
	}
}