fix: delegate multi-line digit selection to visible overlay (#78)

src/media-generator.test.ts

@@ -1,7 +1,60 @@
 import assert from 'node:assert/strict';
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import * as path from 'node:path';
 import test from 'node:test';
 
-import { buildAnimatedImageVideoFilter } from './media-generator';
+import { buildAnimatedImageVideoFilter, MediaGenerator } from './media-generator';
+
+async function withStubbedFfmpeg(
+  run: (generator: MediaGenerator, argsPath: string) => Promise<void>,
+): Promise<void> {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-media-generator-test-'));
+  const binDir = path.join(root, 'bin');
+  const tempDir = path.join(root, 'media');
+  const argsPath = path.join(root, 'ffmpeg-args.txt');
+  fs.mkdirSync(binDir, { recursive: true });
+  const ffmpegPath = path.join(binDir, 'ffmpeg');
+  fs.writeFileSync(
+    ffmpegPath,
+    [
+      '#!/bin/sh',
+      'if [ "$1" = "-hide_banner" ] && [ "$2" = "-encoders" ]; then',
+      '  echo " V..... libaom-av1"',
+      '  exit 0',
+      'fi',
+      'printf "%s\\n" "$@" > "$SUBMINER_TEST_FFMPEG_ARGS"',
+      'out=""',
+      'for arg in "$@"; do out="$arg"; done',
+      'printf avif > "$out"',
+    ].join('\n'),
+    'utf8',
+  );
+  fs.chmodSync(ffmpegPath, 0o755);
+
+  const originalPath = process.env.PATH;
+  const originalArgsPath = process.env.SUBMINER_TEST_FFMPEG_ARGS;
+  process.env.PATH = `${binDir}${path.delimiter}${originalPath ?? ''}`;
+  process.env.SUBMINER_TEST_FFMPEG_ARGS = argsPath;
+  const generator = new MediaGenerator(tempDir);
+
+  try {
+    await run(generator, argsPath);
+  } finally {
+    generator.cleanup();
+    process.env.PATH = originalPath;
+    if (originalArgsPath === undefined) {
+      delete process.env.SUBMINER_TEST_FFMPEG_ARGS;
+    } else {
+      process.env.SUBMINER_TEST_FFMPEG_ARGS = originalArgsPath;
+    }
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+}
+
+function readFfmpegArgs(argsPath: string): string[] {
+  return fs.readFileSync(argsPath, 'utf8').trim().split('\n');
+}
 
 test('buildAnimatedImageVideoFilter prepends a cloned first frame when lead-in is provided', () => {
   assert.equal(
@@ -13,3 +66,89 @@ test('buildAnimatedImageVideoFilter prepends a cloned first frame when lead-in i
     'tpad=start_duration=1.25:start_mode=clone,fps=10,scale=w=640:h=-2',
   );
 });
+
+test('generateAnimatedImage freezes first frame for leading audio padding', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAnimatedImage('/video.mp4', 10, 12, 0.5, {
+      fps: 10,
+      maxWidth: 640,
+    });
+
+    const args = readFfmpegArgs(argsPath);
+    assert.equal(args[args.indexOf('-ss') + 1], '10');
+    assert.equal(args[args.indexOf('-t') + 1], '2.5');
+    assert.equal(
+      args[args.indexOf('-vf') + 1],
+      'tpad=start_duration=0.5:start_mode=clone,fps=10,scale=w=640:h=-2',
+    );
+  });
+});
+
+test('generateAnimatedImage defaults to unpadded sentence timing', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAnimatedImage('/video.mp4', 10, 12, undefined, {
+      fps: 10,
+      maxWidth: 640,
+    });
+
+    const args = readFfmpegArgs(argsPath);
+    assert.equal(args[args.indexOf('-ss') + 1], '10');
+    assert.equal(args[args.indexOf('-t') + 1], '2');
+    assert.equal(args[args.indexOf('-vf') + 1], 'fps=10,scale=w=640:h=-2');
+  });
+});
+
+test('generateAnimatedImage adds audio lead padding to existing word-audio lead-in', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAnimatedImage('/video.mp4', 10, 12, 0.5, {
+      fps: 10,
+      maxWidth: 640,
+      leadingStillDuration: 1.25,
+    });
+
+    const args = readFfmpegArgs(argsPath);
+    assert.equal(args[args.indexOf('-ss') + 1], '10');
+    assert.equal(args[args.indexOf('-t') + 1], '2.5');
+    assert.equal(
+      args[args.indexOf('-vf') + 1],
+      'tpad=start_duration=1.75:start_mode=clone,fps=10,scale=w=640:h=-2',
+    );
+  });
+});
+
+test('generateAnimatedImage clips leading audio padding at the start of media', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAnimatedImage('/video.mp4', 0.2, 1.2, 0.5, {
+      fps: 10,
+      maxWidth: 640,
+    });
+
+    const args = readFfmpegArgs(argsPath);
+    assert.equal(args[args.indexOf('-ss') + 1], '0.2');
+    assert.equal(args[args.indexOf('-t') + 1], '1.5');
+    assert.equal(
+      args[args.indexOf('-vf') + 1],
+      'tpad=start_duration=0.2:start_mode=clone,fps=10,scale=w=640:h=-2',
+    );
+  });
+});
+
+test('generateAudio defaults to unpadded sentence timing', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAudio('/video.mp4', 10, 12);
+
+    const args = readFfmpegArgs(argsPath);
+    assert.equal(args[args.indexOf('-ss') + 1], '10');
+    assert.equal(args[args.indexOf('-t') + 1], '2');
+  });
+});
+
+test('generateAudio clips leading padding without adding it to trailing duration', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAudio('/video.mp4', 0.2, 1.2, 0.5);
+
+    const args = readFfmpegArgs(argsPath);
+    assert.equal(args[args.indexOf('-ss') + 1], '0');
+    assert.equal(args[args.indexOf('-t') + 1], '1.7');
+  });
+});