feat(theme): add Material You tonal palette

src/features/theme/services/MaterialYouPalette.test.ts

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
+import { createMaterialYouScheme, MATERIAL_YOU_STABLE_SEED } from './MaterialYouPalette.ts';
+
+describe('createMaterialYouScheme', () => {
+    it('creates a deterministic stable blue light scheme', () => {
+        const first = createMaterialYouScheme(MATERIAL_YOU_STABLE_SEED, 'light');
+        const second = createMaterialYouScheme(MATERIAL_YOU_STABLE_SEED, 'light');
+
+        assert.deepEqual(first, second);
+        assert.equal(first.seed, '#5B74EF');
+        assert.equal(first.onSurface, '#171B2C');
+        assert.notEqual(first.surface, first.surfaceContainer);
+    });
+
+    it('orders dark tonal surfaces from darkest to lightest', () => {
+        const scheme = createMaterialYouScheme('#8F7CF7', 'dark');
+
+        assert.deepEqual(
+            [scheme.surface, scheme.surfaceContainer, scheme.surfaceContainerHigh],
+            ['#11131A', '#191B23', '#24262F'],
+        );
+        assert.equal(scheme.onSurface, '#E4E6F0');
+    });
+
+    it('uses true black only for the base pure-black surface', () => {
+        const scheme = createMaterialYouScheme('#5B74EF', 'dark', true);
+
+        assert.equal(scheme.surface, '#000000');
+        assert.notEqual(scheme.surfaceContainer, '#000000');
+        assert.notEqual(scheme.primary, scheme.onPrimary);
+    });
+
+    it('normalizes invalid seeds to the stable seed', () => {
+        assert.deepEqual(createMaterialYouScheme('not-a-color', 'dark'), createMaterialYouScheme('#5B74EF', 'dark'));
+    });
+});