feat(core): add Electron runtime, services, and app composition

src/main/runtime/mpv-subtitle-render-metrics.test.ts

@@ -0,0 +1,63 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { createUpdateMpvSubtitleRenderMetricsHandler } from './mpv-subtitle-render-metrics';
+import type { MpvSubtitleRenderMetrics } from '../../types';
+
+const BASE_METRICS: MpvSubtitleRenderMetrics = {
+  subPos: 100,
+  subFontSize: 36,
+  subScale: 1,
+  subMarginY: 0,
+  subMarginX: 0,
+  subFont: '',
+  subSpacing: 0,
+  subBold: false,
+  subItalic: false,
+  subBorderSize: 0,
+  subShadowOffset: 0,
+  subAssOverride: 'yes',
+  subScaleByWindow: true,
+  subUseMargins: true,
+  osdHeight: 0,
+  osdDimensions: null,
+};
+
+test('subtitle render metrics handler no-ops when patch does not change state', () => {
+  let metrics = { ...BASE_METRICS };
+  let broadcasts = 0;
+  const updateMetrics = createUpdateMpvSubtitleRenderMetricsHandler({
+    getCurrentMetrics: () => metrics,
+    setCurrentMetrics: (next) => {
+      metrics = next;
+    },
+    applyPatch: (current) => ({ next: current, changed: false }),
+    broadcastMetrics: () => {
+      broadcasts += 1;
+    },
+  });
+
+  updateMetrics({});
+  assert.equal(broadcasts, 0);
+});
+
+test('subtitle render metrics handler updates and broadcasts when changed', () => {
+  let metrics = { ...BASE_METRICS };
+  let broadcasts = 0;
+  const updateMetrics = createUpdateMpvSubtitleRenderMetricsHandler({
+    getCurrentMetrics: () => metrics,
+    setCurrentMetrics: (next) => {
+      metrics = next;
+    },
+    applyPatch: (current, patch) => ({
+      next: { ...current, ...patch },
+      changed: true,
+    }),
+    broadcastMetrics: () => {
+      broadcasts += 1;
+    },
+  });
+
+  updateMetrics({ subPos: 80 });
+  assert.equal(metrics.subPos, 80);
+  assert.equal(broadcasts, 1);
+});