Add a test (#77)

* Match Prettier style

This way, people who have Prettier as their default formatter in their Editor (probably the majority of people) will not have the code re-formatted to double quotes if they are saving

* Add trailing-comma option

* Instruct .vscode to use ESLint as a default formatter

* Discard changes to package.json

* Add a first test

* Setup CI

* Rename to test

* move tsconfig hacks to local tsconfig.json

* Better test title

* rename file

* Fix ts setup

test/read-mp4.test.ts

@@ -0,0 +1,51 @@
+import { expect, test } from 'vitest';
+import { ALL_FORMATS, MP4, StreamSource, EncodedPacketSink, Input } from '../src/index.js';
+import { open } from 'node:fs/promises';
+
+const __dirname = new URL('.', import.meta.url).pathname;
+
+const fileHandle = await open(
+	`${__dirname}/files/video.mp4`,
+	'r',
+);
+
+const source = new StreamSource({
+	read: async (start, end) => {
+		const buffer = Buffer.alloc(end - start);
+		await fileHandle.read(buffer, 0, end - start, start);
+		return buffer;
+	},
+	getSize: async () => {
+		const { size } = await fileHandle.stat();
+		return size;
+	},
+});
+
+test('Should be able to get packets from a .MP4 file', async () => {
+	const input = new Input({
+		formats: ALL_FORMATS,
+		source,
+	});
+
+	expect(await input.getFormat()).toBe(MP4);
+	expect(await input.getMimeType()).toBe('video/mp4; codecs="avc1.640028, mp4a.40.2"');
+	expect(await input.computeDuration()).toBe(5.056);
+
+	const track = await input.getPrimaryVideoTrack();
+	if (!track) throw new Error('No video track found');
+
+	const sink = new EncodedPacketSink(track);
+
+	let samples = 0;
+	const timestamps: number[] = [];
+
+	for await (const packet of sink.packets()) {
+		timestamps.push(packet.timestamp);
+		samples++;
+	}
+
+	expect(samples).toBe(125);
+	expect(timestamps.slice(0, 10)).toEqual([
+		0, 0.16, 0.08, 0.04, 0.12, 0.32, 0.24, 0.2, 0.28, 0.48,
+	]);
+});