feat(desktop): select several tasks in the Session rail

apps/desktop/src/main/__tests__/session-navigation-selection.test.ts

@@ -0,0 +1,119 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import assert from 'node:assert/strict';
+import { describe, test } from 'node:test';
+import {
+  EMPTY_SESSION_SELECTION,
+  enterSessionSelection,
+  exitSessionSelection,
+  pruneSessionSelection,
+  sessionSelectionMasterState,
+  setAllSessionsSelected,
+  type SessionSelection,
+} from '../../renderer/features/session-navigation/testing.js';
+
+const GROUP = ['a', 'b', 'c', 'd', 'e'];
+
+function ids(selection: SessionSelection): string[] {
+  return [...selection.selectedIds].sort();
+}
+
+/** What a row's checkbox does, as the hook applies it. */
+function mark(selection: SessionSelection, sessionId: string): SessionSelection {
+  return {
+    active: true,
+    selectedIds: new Set([...selection.selectedIds, sessionId]),
+  };
+}
+
+describe('selection mode', () => {
+  test('entering marks nothing on its own', () => {
+    const entered = enterSessionSelection(EMPTY_SESSION_SELECTION);
+    assert.equal(entered.active, true);
+    assert.deepEqual(ids(entered), []);
+  });
+
+  test('leaving drops the mode and the marks together', () => {
+    assert.equal(exitSessionSelection().active, false);
+    assert.deepEqual(ids(exitSessionSelection()), []);
+  });
+
+  test('unticking every row is select-none, not leave', () => {
+    // A mode that ended itself on the last untick would take the checkboxes
+    // away mid-gesture, and one mis-click would cost the user the way back.
+    const all = setAllSessionsSelected(EMPTY_SESSION_SELECTION, GROUP, true);
+    const none = setAllSessionsSelected(all, GROUP, false);
+    assert.deepEqual(ids(none), []);
+    assert.equal(none.active, true);
+  });
+
+  test('an emptied selection keeps the mode it was in', () => {
+    // It used to settle on the shared EMPTY value, which also carries
+    // `active: false` — so a catalog change that pruned the last row would have
+    // taken the checkboxes away while the user was still selecting.
+    const pruned = pruneSessionSelection(mark(EMPTY_SESSION_SELECTION, 'a'), []);
+    assert.deepEqual(ids(pruned), []);
+    assert.equal(pruned.active, true);
+  });
+});
+
+describe('the master box', () => {
+  test('marks exactly the rows the rail is listing', () => {
+    // Not every task in the catalog: the box sits above these rows, and a
+    // selection that reached past them would name a number nobody agreed to.
+    assert.deepEqual(ids(setAllSessionsSelected(EMPTY_SESSION_SELECTION, ['a', 'b'], true)), [
+      'a',
+      'b',
+    ]);
+  });
+
+  test('reads unchecked, indeterminate, then checked', () => {
+    assert.equal(sessionSelectionMasterState(EMPTY_SESSION_SELECTION, GROUP), false);
+    assert.equal(sessionSelectionMasterState(mark(EMPTY_SESSION_SELECTION, 'b'), GROUP), 'indeterminate');
+    assert.equal(
+      sessionSelectionMasterState(setAllSessionsSelected(EMPTY_SESSION_SELECTION, GROUP, true), GROUP),
+      true,
+    );
+  });
+
+  test('an empty list is unchecked, never checked', () => {
+    // `every` over an empty array is vacuously true, which would tick the box
+    // above no rows at all.
+    assert.equal(sessionSelectionMasterState(EMPTY_SESSION_SELECTION, []), false);
+  });
+
+  test('a mark outside the listed rows does not make it checked', () => {
+    assert.equal(sessionSelectionMasterState(mark(EMPTY_SESSION_SELECTION, 'zzz'), GROUP), 'indeterminate');
+  });
+});
+
+describe('pruneSessionSelection', () => {
+  test('drops ids the catalog no longer lists', () => {
+    const selection = setAllSessionsSelected(EMPTY_SESSION_SELECTION, ['a', 'b'], true);
+    assert.deepEqual(ids(pruneSessionSelection(selection, ['a'])), ['a']);
+  });
+
+  test('returns the same value when nothing was dropped', () => {
+    // Identity matters here: this runs on every catalog refresh, and a new Set
+    // each time would re-render every row of the rail.
+    const selection = mark(EMPTY_SESSION_SELECTION, 'a');
+    assert.equal(pruneSessionSelection(selection, ['a', 'b']), selection);
+  });
+});