fix(hub): one entry per file in the Search view's Videos grid

A library shared by two groups arrived in the cross-group Search view as
two entries per file: every film was two poster cards, every episode was
listed twice in the season list under the synopsis. Inside one group
this cannot happen — GroupIndex is keyed by blake3 — so the duplication
was the Search page's own, from concatenating N independently keyed
indexes.

source-merge.js folds entries on the content hash and resolves one
source per *unit* (a film, a whole show), so a season does not scatter
across two nodes. A group hosted by the reader's own node wins; failing
that the pick is a hash of the unit key and the reader's id, stable
across renders and reloads — a source that changed mid-stream would tear
down the connection under a film that is playing — and spread across
readers and units.

The units come from video-app.js's own groupVideoEntries rather than a
second copy of its keys here. Only the Videos view is wired up so far;
Music, Photos, failover and the "N sources" badge are phases 5-8 of
docs/refactoring-search.md.

Every test was checked against the fix removed. That is how the first
version of "a unit's files share its source" turned out to prove
nothing: with every episode in every group, per-file and per-unit
picking give the same answer, so it passed against a per-file
implementation. It now uses a unit whose files have unequal sources.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AbwJDbNTkiRUh7HTWEoyss

1 files changed, 185 insertions, 0 deletions

diff --git a/packages/meshbay-hub/tests/test_search_video_merge.py b/packages/meshbay-hub/tests/test_search_video_merge.py
new file mode 100644
index 0000000..e9ab258
--- /dev/null
+++ b/packages/meshbay-hub/tests/test_search_video_merge.py
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+"""
+The reported symptom, end to end: one library shared by two groups.
+
+`test_search_source_merge.py` holds the merging rules in isolation. This holds
+the thing an operator actually saw — a node hosting two groups that were given
+the same video directory, and a Search view showing every film as two poster
+cards and every episode twice inside a show.
+
+Three pieces have to agree for that to come out right, and each lives in a
+different file:
+
+  * `groupVideoEntries` (video-app.js) turns entries into films and shows;
+  * `videoUnits` (search-page.js) turns those into merge units;
+  * `mergeUnitEntries` (source-merge.js) folds them on the content hash.
+
+All three are read out of their real sources here rather than restated. The
+pipeline is assembled the way `search-page.js` assembles it, and then the
+result is passed through `groupVideoEntries` a second time — which is what
+`VideoApp` does with it — so what this counts is what the grid renders.
+
+See docs/refactoring-search.md.
+"""
+
+import json
+import re
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+STATIC = Path(__file__).resolve().parents[1] / "src" / "meshbay_hub" / "static"
+VIDEO_APP = STATIC / "video-app.js"
+SEARCH_PAGE = STATIC / "search-page.js"
+MERGE = STATIC / "source-merge.js"
+
+pytestmark = pytest.mark.skipif(
+    shutil.which("node") is None or not MERGE.exists(),
+    reason="node or the SPA sources are not available")
+
+EXPORT = re.compile(r"^export \{[^}]*\};?\s*$", re.M)
+
+
+def _block(path, header):
+    """One top-level `function name(...) {` ... `}` read out of a module."""
+    src = path.read_text()
+    m = re.search(r"^" + re.escape(header) + r".*?^\}", src, re.M | re.S)
+    assert m, (
+        f"{header} is no longer where this test reads it from in {path.name} — "
+        "the Search view's de-duplication is untested until this is fixed")
+    return m.group(0)
+
+
+@pytest.fixture(scope="module")
+def pipeline():
+    root = re.search(r"^const SEARCH_VIDEO_ROOT = .*?;$", SEARCH_PAGE.read_text(), re.M)
+    assert root, "SEARCH_VIDEO_ROOT moved — videoUnits cannot be lifted"
+    return "\n".join([
+        EXPORT.sub("", MERGE.read_text()),
+        _block(VIDEO_APP, "function underVideoRoot(entry, videoRoot) {"),
+        _block(VIDEO_APP, "function buildSeasons(episodes) {"),
+        _block(VIDEO_APP, "function groupVideoEntries(entries, videoRoot) {"),
+        root.group(0),
+        _block(SEARCH_PAGE, "function videoUnits(entries) {"),
+    ])
+
+
+def _grid(tmp_path, pipeline, entries, salt="reader", local=()):
+    """What the poster grid ends up with, after the merge and VideoApp's own
+    regrouping."""
+    body = f"""
+      const raw = {json.dumps(entries)};
+      const local = new Set({json.dumps(list(local))});
+      const merged = mergeUnitEntries(videoUnits(raw), {{
+        salt: {json.dumps(salt)},
+        isLocal: (g) => local.has(g),
+      }});
+      const {{ movies, shows }} = groupVideoEntries(merged, SEARCH_VIDEO_ROOT);
+      console.log(JSON.stringify({{
+        movies: movies.map((e) => ({{
+          id: e.id, title: e.display_title || e.name, groupId: e.groupId,
+          sources: e._sources.length,
+        }})),
+        shows: shows.map((s) => ({{
+          title: s.title,
+          groups: [...new Set(s.episodes.map((e) => e.groupId))].sort(),
+          seasons: s.seasons.map((x) => ({{
+            season: x.season,
+            episodes: x.episodes.map((e) => `S${{e.season}}E${{e.episode}}`),
+          }})),
+        }})),
+      }}));
+    """
+    script = tmp_path / "case.js"
+    script.write_text(f"{pipeline}\n{body}\n")
+    out = subprocess.run(
+        ["node", str(script)], capture_output=True, text=True, timeout=30)
+    assert out.returncode == 0, out.stderr
+    return json.loads(out.stdout)
+
+
+# The shape of one shared library: a film, and a two-season show. Invented
+# titles — the real one this was found against is nobody's business here.
+def _library(group):
+    """`path` is already prefixed the way search-page.js prefixes it."""
+    def entry(file_id, name, **kw):
+        return {
+            "id": file_id, "name": name, "type": "video",
+            "path": "__search__/shows", "size": 1,
+            "groupId": group, "groupName": group.upper(), "groupOwner": "someone",
+            "_tRef": f"t:{group}", "_gRef": f"g:{group}", "_connGen": 1,
+            **kw,
+        }
+    files = [entry("film1", "a-film.mkv", display_title="Some Film")]
+    for season in (1, 2):
+        for ep in (1, 2, 3):
+            files.append(entry(
+                f"s{season}e{ep}", f"show.s0{season}e0{ep}.mkv",
+                display_title="Some Saga", season=season, episode=ep))
+    return files
+
+
+def test_a_shared_library_is_listed_once(tmp_path, pipeline):
+    """
+    The bug as reported: two groups, one directory, everything twice.
+    """
+    both = _library("demo35") + _library("media")
+    grid = _grid(tmp_path, pipeline, both)
+
+    assert [m["title"] for m in grid["movies"]] == ["Some Film"]
+    assert grid["movies"][0]["sources"] == 2
+
+    assert len(grid["shows"]) == 1
+    show = grid["shows"][0]
+    assert [s["season"] for s in show["seasons"]] == [1, 2]
+    for season in show["seasons"]:
+        assert season["episodes"] == [
+            f"S{season['season']}E{n}" for n in (1, 2, 3)], (
+            "an episode is listed more than once — this is the reported bug, "
+            "in the season list under the synopsis")
+
+
+def test_a_show_streams_from_one_source(tmp_path, pipeline):
+    """A season split across two nodes would open two connections and two
+    metadata lookups for one show."""
+    both = _library("demo35") + _library("media")
+    show = _grid(tmp_path, pipeline, both)["shows"][0]
+    assert len(show["groups"]) == 1
+
+
+def test_the_operators_own_node_serves_it(tmp_path, pipeline):
+    """Both groups are on the operator's node in the reported case; when only
+    one is, that one is the source."""
+    both = _library("remote") + _library("mine")
+    grid = _grid(tmp_path, pipeline, both, local=["mine"])
+    assert grid["movies"][0]["groupId"] == "mine"
+    assert grid["shows"][0]["groups"] == ["mine"]
+
+
+def test_one_group_is_unchanged(tmp_path, pipeline):
+    """The overwhelmingly common case: nothing to merge, nothing different."""
+    grid = _grid(tmp_path, pipeline, _library("solo"))
+    assert [m["title"] for m in grid["movies"]] == ["Some Film"]
+    assert grid["movies"][0]["sources"] == 1
+    assert grid["movies"][0]["groupId"] == "solo"
+    show = grid["shows"][0]
+    assert show["groups"] == ["solo"]
+    assert sum(len(s["episodes"]) for s in show["seasons"]) == 6
+
+
+def test_an_episode_only_one_group_has_is_kept(tmp_path, pipeline):
+    """
+    Merging must never subtract. A group holding one extra episode contributes
+    it, whichever source the show settled on.
+    """
+    extra = _library("media")
+    extra.append({
+        "id": "s2e4", "name": "show.s02e04.mkv", "type": "video",
+        "path": "__search__/shows", "size": 1,
+        "groupId": "media", "groupName": "MEDIA", "groupOwner": "someone",
+        "display_title": "Some Saga", "season": 2, "episode": 4,
+    })
+    grid = _grid(tmp_path, pipeline, _library("demo35") + extra)
+    season2 = [s for s in grid["shows"][0]["seasons"] if s["season"] == 2][0]
+    assert season2["episodes"] == ["S2E1", "S2E2", "S2E3", "S2E4"]