feat: the library's folders are set in Admin › Library, and changing a folder moves its tracks with it, keeping their plays, likes and playlists (#6129)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/library/library_paths_test.go

@@ -0,0 +1,148 @@
+package library
+
+import (
+	"context"
+	"errors"
+	"io"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
+)
+
+func mkdir(t *testing.T, parts ...string) string {
+	t.Helper()
+	p := filepath.Join(parts...)
+	if err := os.MkdirAll(p, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	return p
+}
+
+func TestPlanRoots(t *testing.T) {
+	base := t.TempDir()
+	music := mkdir(t, base, "music")
+	data := mkdir(t, base, "data", "music")
+	more := mkdir(t, base, "more")
+	file := filepath.Join(base, "a.mp3")
+	if err := os.WriteFile(file, []byte("x"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	current := []string{music, more}
+
+	roots, moves, err := planRoots(current, []RootChange{{Path: data + "/", Was: music}, {Path: more, Was: more}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !slices.Equal(roots, []string{data, more}) {
+		t.Errorf("roots %v", roots)
+	}
+	if len(moves) != 1 || moves[0] != (RootChange{Path: data, Was: music}) {
+		t.Errorf("moves %v; want only %s → %s", moves, music, data)
+	}
+
+	for name, tc := range map[string]struct {
+		changes  []RootChange
+		mentions string
+	}{
+		"none":         {nil, "At least one"},
+		"relative":     {[]RootChange{{Path: "music"}}, "full path"},
+		"root":         {[]RootChange{{Path: "/"}}, "whole filesystem"},
+		"absent":       {[]RootChange{{Path: filepath.Join(base, "nope")}}, "does not exist"},
+		"a file":       {[]RootChange{{Path: file}}, "not a folder"},
+		"twice":        {[]RootChange{{Path: music}, {Path: music}}, "twice"},
+		"nested":       {[]RootChange{{Path: base}, {Path: music}}, "overlap"},
+		"unknown was":  {[]RootChange{{Path: data, Was: "/elsewhere"}}, "not one of"},
+		"split a move": {[]RootChange{{Path: data, Was: music}, {Path: more, Was: music}}, "one place"},
+	} {
+		_, _, err := planRoots(current, tc.changes)
+		var re *RootsError
+		if !errors.As(err, &re) || !strings.Contains(err.Error(), tc.mentions) {
+			t.Errorf("%s: err %v; want a RootsError mentioning %q", name, err, tc.mentions)
+		}
+	}
+}
+
+// clearSavedRoots puts the folders back to env afterwards. It also finishes any
+// scan an earlier test left running: dbtest.ResetDB keeps scan_runs, and a
+// save refuses while a scan is in flight.
+func clearSavedRoots(t *testing.T, pool *pgxpool.Pool) {
+	t.Helper()
+	if _, err := pool.Exec(context.Background(),
+		`UPDATE scan_runs SET finished_at = now() WHERE finished_at IS NULL`); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		_, _ = pool.Exec(context.Background(), `UPDATE library_settings SET scan_paths = NULL`)
+	})
+}
+
+func TestSetRoots_TracksMoveWithTheirFolder_Integration(t *testing.T) {
+	pool := newPool(t)
+	clearSavedRoots(t, pool)
+	ctx := context.Background()
+	base := t.TempDir()
+	old := filepath.Join(base, "music") // gone: the mount moved
+	moved := mkdir(t, base, "data", "music", "Artist")
+	if err := os.WriteFile(filepath.Join(moved, "a.mp3"), []byte("x"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	newRoot := filepath.Dir(moved)
+	track, _, _ := seedTrack(t, pool, filepath.Join(old, "Artist", "a.mp3"))
+
+	s := New(pool, slog.New(slog.NewTextHandler(io.Discard, nil)), []string{old}, nil)
+	res, err := s.SetRoots(ctx, []RootChange{{Path: newRoot, Was: old}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if res.Tracks != 1 {
+		t.Errorf("moved %d tracks; want 1", res.Tracks)
+	}
+	got, err := dbq.New(pool).GetTrackByPath(ctx, filepath.Join(newRoot, "Artist", "a.mp3"))
+	if err != nil {
+		t.Fatalf("the track is not at its new path: %v", err)
+	}
+	if got.ID != track.ID {
+		t.Error("the move made a new track instead of keeping the old one")
+	}
+	if !slices.Equal(s.Roots(), []string{newRoot}) {
+		t.Errorf("roots %v", s.Roots())
+	}
+	select {
+	case <-s.RootsChanged():
+	default:
+		t.Error("the watcher was not told the folders changed")
+	}
+	roots, saved, err := LoadRoots(ctx, pool, []string{old})
+	if err != nil || !saved || !slices.Equal(roots, []string{newRoot}) {
+		t.Errorf("after a restart: %v saved=%v err=%v; want the saved folder over env", roots, saved, err)
+	}
+}
+
+func TestSetRoots_RefusesAMoveToAFolderWithoutTheFiles_Integration(t *testing.T) {
+	pool := newPool(t)
+	clearSavedRoots(t, pool)
+	ctx := context.Background()
+	base := t.TempDir()
+	old := filepath.Join(base, "music")
+	wrong := mkdir(t, base, "elsewhere")
+	seedTrack(t, pool, filepath.Join(old, "a.mp3"))
+
+	s := New(pool, slog.New(slog.NewTextHandler(io.Discard, nil)), []string{old}, nil)
+	var re *RootsError
+	if _, err := s.SetRoots(ctx, []RootChange{{Path: wrong, Was: old}}); !errors.As(err, &re) {
+		t.Fatalf("err %v; want a RootsError", err)
+	}
+	if _, err := dbq.New(pool).GetTrackByPath(ctx, filepath.Join(old, "a.mp3")); err != nil {
+		t.Errorf("a refused move rewrote the track: %v", err)
+	}
+	if !slices.Equal(s.Roots(), []string{old}) {
+		t.Errorf("a refused move changed the folders to %v", s.Roots())
+	}
+}