Add exit unit test

wasm/tests/exit.test.js

+const fs = require('fs');
+const path = require('path');
+const { TIMEOUT } = require('./config');
+const { runFFmpeg } = require('./utils');
+const IN_FILE_NAME = 'video-1s.avi';
+const OUT_FILE_NAME = 'video.mp4';
+const FILE_SIZE = 38372;
+let aviData = null;
+
+beforeAll(() => {
+  aviData = Uint8Array.from(fs.readFileSync(path.join(__dirname, 'data', IN_FILE_NAME)));
+});
+
+test('transcode avi to x264 mp4 with exit', async () => {
+  const processExit = process.exit;
+  global.process.exit = jest.fn();
+  const args = ['-i', IN_FILE_NAME, OUT_FILE_NAME];
+  const { fileSize } = await runFFmpeg(IN_FILE_NAME, aviData, args, OUT_FILE_NAME, [], [], 1000);
+  expect(fileSize).not.toBe(FILE_SIZE);
+  global.process.exit = processExit;
+}, TIMEOUT);

wasm/tests/utils.js

@@ -19,7 +19,7 @@ const ffmpeg = (Core, args) => {
   );
 };
 
-const runFFmpeg = async (ifilename, data, args, ofilename, extraFiles = [], extraFolders = []) => {
+const runFFmpeg = async (ifilename, data, args, ofilename, extraFiles = [], extraFolders = [], msBeforeExit = -1) => {
   let resolve = null;
   let file = null;
   let fileSize = -1;
@@ -39,6 +39,12 @@ const runFFmpeg = async (ifilename, data, args, ofilename, extraFiles = [], extr
   });
   Core.FS.writeFile(ifilename, data);
   ffmpeg(Core, args);
+  if (msBeforeExit !== -1) {
+    setTimeout(() => {
+      Core.exit();
+      resolve();
+    }, msBeforeExit);
+  }
   await new Promise((_resolve) => { resolve = _resolve });
   if (typeof ofilename !== 'undefined') {
     file = Core.FS.readFile(ofilename);