stitcher function

test/stitcher.test.ts

@@ -0,0 +1,87 @@
+import { Stitcher } from '../src/stitcher.js';
+import { describe, expect, it, vi, beforeEach } from 'vitest';
+import { EventEmitter } from 'events';
+import { spawn } from 'child_process';
+
+const mockChildProcess = new (class MockChildProcess
+    extends EventEmitter {
+    kill = vi.fn(() => {
+        return true;
+    });
+})();
+
+vi.mock('child_process', () => {
+    return {
+        spawn: vi.fn(() => mockChildProcess)
+    }
+});
+
+describe('stitcher', () => {
+
+    beforeEach(() => {
+        vi.clearAllMocks();
+    });
+
+    it('passes the correct arguments to ffmpeg', async () => {
+        const p = Stitcher(['1.flac', 'dir/2.flac']);
+        mockChildProcess.emit('exit', 0, null);
+        await p;
+        expect(spawn).toBeCalledWith('ffmpeg', [
+            "-i",
+            '1.flac',
+            '-i',
+            'dir/2.flac',
+            '-filter_complex',
+            '[0:a][1:a][2:a]concat=n=2:v=0:a=1[out]',
+            '-map',
+            '[out]',
+            '-ar',
+            '44100',
+            '-ac',
+            '2',
+            '-c:a',
+            'pcm_s16le',
+            'output.wav'
+        ]);
+    });
+
+    it('throws an error when ffmpeg fails', async () => {
+        const p = Stitcher(['sound.mp3']);
+        mockChildProcess.emit('exit', 1, null);
+        await expect(p).rejects.toThrow('exited with 1');
+        expect(spawn).toBeCalledWith('ffmpeg', [
+            "-i",
+            'sound.mp3',
+            '-filter_complex',
+            '[0:a][1:a][2:a]concat=n=1:v=0:a=1[out]',
+            '-map',
+            '[out]',
+            '-ar',
+            '44100',
+            '-ac',
+            '2',
+            '-c:a',
+            'pcm_s16le',
+            'output.wav'
+        ]);
+    });
+
+    it('throws an error when ffmpeg takes longer than expected', { timeout: 6000 }, async () => {
+        await expect(Stitcher(['in.wav'])).rejects.toThrow('timed out');
+        expect(spawn).toBeCalledWith('ffmpeg', [
+            "-i",
+            'in.wav',
+            '-filter_complex',
+            '[0:a][1:a][2:a]concat=n=1:v=0:a=1[out]',
+            '-map',
+            '[out]',
+            '-ar',
+            '44100',
+            '-ac',
+            '2',
+            '-c:a',
+            'pcm_s16le',
+            'output.wav'
+        ]);
+    });
+});