add reorder tracks options to playlist page context menu

sharedutil/sharedutil_test.go

@@ -0,0 +1,91 @@
+package sharedutil
+
+import (
+	"testing"
+
+	"github.com/dweymouth/go-subsonic/subsonic"
+)
+
+func Test_ReorderTracks(t *testing.T) {
+	tracks := []*subsonic.Child{
+		{ID: "a"}, // 0
+		{ID: "b"}, // 1
+		{ID: "c"}, // 2
+		{ID: "d"}, // 3
+		{ID: "e"}, // 4
+		{ID: "f"}, // 5
+	}
+
+	// test MoveToTop:
+	idxToMove := []int{0, 2, 3, 5}
+	want := []*subsonic.Child{
+		{ID: "a"},
+		{ID: "c"},
+		{ID: "d"},
+		{ID: "f"},
+		{ID: "b"},
+		{ID: "e"},
+	}
+	newTracks := ReorderTracks(tracks, idxToMove, MoveToTop)
+	if !tracklistsEqual(t, newTracks, want) {
+		t.Error("ReorderTracks: MoveToTop order incorrect")
+	}
+
+	// test MoveToBottom:
+	idxToMove = []int{0, 2, 5}
+	want = []*subsonic.Child{
+		{ID: "b"},
+		{ID: "d"},
+		{ID: "e"},
+		{ID: "a"},
+		{ID: "c"},
+		{ID: "f"},
+	}
+	newTracks = ReorderTracks(tracks, idxToMove, MoveToBottom)
+	if !tracklistsEqual(t, newTracks, want) {
+		t.Error("ReorderTracks: MoveToBottom order incorrect")
+	}
+
+	// test MoveUp:
+	idxToMove = []int{0, 1, 3, 5}
+	want = []*subsonic.Child{
+		{ID: "a"},
+		{ID: "b"},
+		{ID: "d"},
+		{ID: "c"},
+		{ID: "f"},
+		{ID: "e"},
+	}
+	newTracks = ReorderTracks(tracks, idxToMove, MoveUp)
+	if !tracklistsEqual(t, newTracks, want) {
+		t.Error("ReorderTracks: MoveUp order incorrect")
+	}
+
+	// test MoveDown:
+	idxToMove = []int{2, 4, 5}
+	want = []*subsonic.Child{
+		{ID: "a"},
+		{ID: "b"},
+		{ID: "d"},
+		{ID: "c"},
+		{ID: "e"},
+		{ID: "f"},
+	}
+	newTracks = ReorderTracks(tracks, idxToMove, MoveDown)
+	if !tracklistsEqual(t, newTracks, want) {
+		t.Error("ReorderTracks: MoveDown order incorrect")
+	}
+}
+
+func tracklistsEqual(t *testing.T, a, b []*subsonic.Child) bool {
+	t.Helper()
+	if len(a) != len(b) {
+		return false
+	}
+	for i, _ := range a {
+		if a[i].ID != b[i].ID {
+			return false
+		}
+	}
+	return true
+}