Swimlanes: a shared card no longer appears in every swimlane (doubled cards).

In swimlanes view a card with swimlaneId null/'' (a 'shared' / pre-migration card) was surfaced in EVERY swimlane: swimlaneMembershipSelector used { swimlaneId: { $in: [swimlaneId, null, ''] } } for non-first swimlanes, and filterCardsByListAndSwimlane matched null/''/missing there too. On a board with several swimlanes the same shared card therefore rendered once per swimlane -- the reported 'doubled cards/entries', which also bloats the DOM (contributing to the search hang / can't-scroll on big boards). A non-first swimlane now matches ONLY its own cards ({ swimlaneId }); shared and orphaned cards surface ONCE, in the FIRST swimlane (the $nin branch, unchanged), so a card is never shown in more than one swimlane. Still a single field clause, so the #6441 board-wide label-filter fix is preserved (verified in the tests).

Tests: tests/swimlaneFilter.test.cjs updated -- a non-first swimlane matches only its own cards; shared/orphaned cards appear once in the first swimlane and are still filtered by the active label filter; #6441 board-wide filtering for cards that HAVE a swimlaneId is unchanged. 18 checks pass.

Thanks to xet7.

models/lib/swimlaneFilter.js

@@ -52,13 +52,21 @@
 function swimlaneMembershipSelector(swimlaneId, otherSwimlaneIds) {
   if (!swimlaneId) return {};
   if (Array.isArray(otherSwimlaneIds)) {
-    // First swimlane: everything in the list that is NOT owned by another
-    // existing swimlane (own id, null/'', missing, or orphaned).
+    // FIRST swimlane: everything in the list NOT owned by another existing
+    // swimlane — its own cards, shared cards (null/''/missing) AND orphaned cards
+    // (a swimlaneId pointing at a deleted swimlane). This is where shared/orphaned
+    // cards surface — ONCE.
     return { swimlaneId: { $nin: otherSwimlaneIds } };
   }
-  // `$in` with null matches swimlaneId === null AND a missing swimlaneId field;
-  // '' covers the empty-string value from the shared-lists era.
-  return { swimlaneId: { $in: [swimlaneId, null, ''] } };
+  // NON-first swimlane: ONLY its own cards. Shared cards (null/'') are NOT
+  // surfaced here — they appear once, in the FIRST swimlane above — so a card is
+  // never shown in more than one swimlane. Previously this was
+  // `{ swimlaneId: { $in: [swimlaneId, null, ''] } }`, which put every shared /
+  // pre-migration card (swimlaneId null) into EVERY swimlane, so on a multi-
+  // swimlane board those cards appeared once per swimlane — the reported "doubled
+  // cards". Still a single field clause (no second $or), so the #6441 board-wide
+  // filter fix is preserved.
+  return { swimlaneId };
 }
 
 // Base (unfiltered) selector for the active cards of one list, optionally

models/lists.js

@@ -18,10 +18,12 @@ const Lists = new Mongo.Collection('lists');
 //
 // - When `swimlaneId` is undefined (no swimlane context), every card in the
 //   list is returned (preserves the historical "select all in list" behavior).
-// - When `swimlaneId` is provided, a card matches when its `swimlaneId` equals
-//   the given value, OR the card has no swimlane at all (null / '' / missing),
-//   mirroring `cards()` so orphaned/pre-migration cards stay selectable in
-//   every swimlane.
+// - When `swimlaneId` is provided (a NON-first swimlane), a card matches only
+//   when its `swimlaneId` equals the given value. Shared / pre-migration cards
+//   (swimlaneId null / '' / missing) are NOT surfaced here — they surface once,
+//   in the FIRST swimlane (the otherSwimlaneIds branch), so a card is never
+//   selected in more than one swimlane (mirrors swimlaneMembershipSelector; the
+//   "doubled cards" fix).
 // - #6443: when `otherSwimlaneIds` is provided (the board's OTHER swimlane ids,
 //   i.e. this is the FIRST swimlane), a card also matches when its swimlaneId is
 //   "orphaned" — a non-empty value that is not one of the board's existing
@@ -46,12 +48,9 @@ export function filterCardsByListAndSwimlane(cards, listId, swimlaneId, otherSwi
       // swimlane (own id, null/'', missing, or orphaned all pass).
       return !otherSwimlaneIds.includes(cardSwimlaneId);
     }
-    return (
-      cardSwimlaneId === swimlaneId ||
-      cardSwimlaneId === null ||
-      cardSwimlaneId === undefined ||
-      cardSwimlaneId === ''
-    );
+    // NON-first swimlane: ONLY its own cards — shared cards surface once, in the
+    // first swimlane above.
+    return cardSwimlaneId === swimlaneId;
   });
 }
 

tests/swimlaneFilter.test.cjs

@@ -88,9 +88,11 @@ const BACKGROUND = 'swimlane-background';
 const LIST = 'list-1';
 
 // --- swimlaneMembershipSelector ---------------------------------------------
-test('swimlaneMembershipSelector uses a single $in clause, not a top-level $or', () => {
+test('a NON-first swimlane clause is a single own-swimlane match (no $or)', () => {
   const sel = swimlaneMembershipSelector(BACKGROUND);
-  assert.deepStrictEqual(sel, { swimlaneId: { $in: [BACKGROUND, null, ''] } });
+  // Doubled-cards fix: a non-first swimlane matches ONLY its own cards; shared
+  // cards (null/'') surface once, in the first swimlane (the $nin branch).
+  assert.deepStrictEqual(sel, { swimlaneId: BACKGROUND });
   assert.ok(!('$or' in sel), 'must NOT introduce a top-level $or (#6441)');
 });
 
@@ -99,12 +101,12 @@ test('swimlaneMembershipSelector is empty without a swimlane context', () => {
   assert.deepStrictEqual(swimlaneMembershipSelector(''), {});
 });
 
-test('the swimlane clause matches the swimlane plus orphaned/shared cards', () => {
+test('a non-first swimlane clause matches ONLY its own cards, not shared/orphaned', () => {
   const sel = swimlaneMembershipSelector(BACKGROUND);
   assert.ok(docMatches(sel, { swimlaneId: BACKGROUND }));
-  assert.ok(docMatches(sel, { swimlaneId: null }));
-  assert.ok(docMatches(sel, { swimlaneId: '' }));
-  assert.ok(docMatches(sel, {}), 'missing swimlaneId is treated as orphaned');
+  assert.ok(!docMatches(sel, { swimlaneId: null }), 'shared card surfaces in the FIRST swimlane, not here');
+  assert.ok(!docMatches(sel, { swimlaneId: '' }), 'empty/shared surfaces in the first swimlane');
+  assert.ok(!docMatches(sel, {}), 'missing swimlaneId surfaces in the first swimlane');
   assert.ok(!docMatches(sel, { swimlaneId: FOCUS }), 'other swimlane excluded');
 });
 
@@ -162,15 +164,22 @@ test('#6441: matching result is identical across swimlanes for the same card', (
   });
 });
 
-test('#6441: an orphaned (no swimlane) card is filtered consistently in every swimlane', () => {
+test('shared/orphaned (no-swimlane) cards surface ONCE, in the first swimlane (not every)', () => {
+  // Doubled-cards fix: previously these matched in EVERY swimlane; now a non-first
+  // swimlane does not show them, and the first swimlane shows them once. The label
+  // filter still applies (an unlabelled card is hidden even in the first swimlane).
   const orphanLabelled = { _id: 'c7', listId: LIST, archived: false }; // no swimlaneId, no labels
   const orphanWithLabel = { _id: 'c8', listId: LIST, archived: false, labelIds: [RECURRING] };
 
+  // NON-first swimlanes: shared cards are not shown (no duplication).
   [FOCUS, BACKGROUND].forEach(swimlaneId => {
     const sel = filteredListCardsSelector(LIST, swimlaneId, labelFilterSelector(RECURRING));
-    assert.ok(!docMatches(sel, orphanLabelled), `orphaned unlabelled card hidden in ${swimlaneId}`);
-    assert.ok(docMatches(sel, orphanWithLabel), `orphaned labelled card shown in ${swimlaneId}`);
+    assert.ok(!docMatches(sel, orphanWithLabel), `shared card NOT in non-first swimlane ${swimlaneId}`);
   });
+  // FIRST swimlane (otherSwimlaneIds passed): shown once, still filtered by label.
+  const firstSel = filteredListCardsSelector(LIST, BACKGROUND, labelFilterSelector(RECURRING), [FOCUS]);
+  assert.ok(docMatches(firstSel, orphanWithLabel), 'shared labelled card shown once in the first swimlane');
+  assert.ok(!docMatches(firstSel, orphanLabelled), 'unlabelled shared card still hidden by the label filter');
 });
 
 // --- do not regress other filter types --------------------------------------
@@ -212,10 +221,11 @@ test('#6443: first swimlane surfaces own, shared AND orphaned cards; excludes ot
   assert.ok(!docMatches(sel, { swimlaneId: FOCUS }), 'card owned by another existing swimlane excluded');
 });
 
-test('#6443: a non-first swimlane does NOT show orphaned cards (own + shared only)', () => {
+test('a non-first swimlane shows ONLY its own cards (shared + orphaned surface once, in the first)', () => {
   const sel = swimlaneMembershipSelector(FOCUS); // no otherSwimlaneIds passed
   assert.ok(docMatches(sel, { swimlaneId: FOCUS }));
-  assert.ok(docMatches(sel, { swimlaneId: null }));
+  assert.ok(!docMatches(sel, { swimlaneId: null }), 'shared card is NOT duplicated into non-first swimlanes');
+  assert.ok(!docMatches(sel, { swimlaneId: '' }), 'empty/shared card not duplicated here');
   assert.ok(!docMatches(sel, { swimlaneId: DELETED }), 'orphaned card is not duplicated into non-first swimlanes');
 });