blogposts: test get blog content

blogposts/blogposts.go

@@ -1,12 +1,43 @@
 package blogposts
 
-import "io/fs"
+import (
+	"io"
+	"io/fs"
+)
 
 type Post struct {
 	Title, Description, Body string
 	Tags                     []string
 }
 
-func NewPostsFromFS(fs fs.FS) []Post {
-	return []Post{{}, {}}
+func NewPostsFromFS(fileSystem fs.FS) ([]Post, error) {
+	dir, err := fs.ReadDir(fileSystem, ".")
+	if err != nil {
+		return nil, err
+	}
+	var posts []Post
+	for _, f := range dir {
+		post, err := getPost(fileSystem, f)
+		if err != nil {
+			return nil, err
+		}
+		posts = append(posts, post)
+	}
+	return posts, nil
+}
+
+func getPost(fileSystem fs.FS, f fs.DirEntry) (Post, error) {
+	postFile, err := fileSystem.Open(f.Name())
+	if err != nil {
+		return Post{}, err
+	}
+	defer postFile.Close()
+
+	postData, err := io.ReadAll(postFile)
+	if err != nil {
+		return Post{}, err
+	}
+
+	post := Post{Title: string(postData)[7:]}
+	return post, nil
 }

blogposts/blogposts_test.go

@@ -1,20 +1,40 @@
 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("hi")},
-		"hello-world2.md": {Data: []byte("hola")},
+		"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)
 	}
 
-	posts := NewPostsFromFS(fs)
 	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)
+	}
 }