fix: bug that causes an error when dirwalking to a non-existent direc…

…tory.

fix: #1

broker.go

@@ -143,6 +143,10 @@ func (b *Broker) FetchLocalArticles() (articles map[string]*Article, err error)
 }
 
 func dirwalk(dir string) ([]string, error) {
+	err := os.MkdirAll(dir, 0755)
+	if err != nil {
+		return nil, fmt.Errorf("make dir: %w", err)
+	}
 	files, err := ioutil.ReadDir(dir)
 	if err != nil {
 		return nil, fmt.Errorf("read dir: %w", err)

broker_test.go

@@ -909,12 +909,6 @@ func Test_fetchLocalArticles(t *testing.T) {
 				Local: localConfig{Dir: filepath.Join("testdata", "duplicate")}}},
 			wantErr: true,
 		},
-		{
-			name: "dummy_dir",
-			fields: fields{config: &Config{
-				Local: localConfig{Dir: "dummy"}}},
-			wantErr: true,
-		},
 	}
 
 	if err := os.Chtimes(filepath.Join("testdata", "article", "20_test_article_posted.md"), updateAt, updateAt); err != nil {
@@ -1159,13 +1153,6 @@ func Test_dirwalk(t *testing.T) {
 	}
 }
 
-func Test_dirwalk_dummyDir(t *testing.T) {
-	_, err := dirwalk("dummy")
-	if err == nil {
-		t.Errorf("expect to occur error but nothing: %v", err)
-	}
-}
-
 func setup() (broker *Broker, mux *http.ServeMux, serverURL string, teardown func()) {
 	mux = http.NewServeMux()