prettier 2

Summary:
Quick notes:

- This looks worse than it is. It adds mandatory parentheses to single argument lambdas. Lots of outrage on Twitter about it, personally I'm {emoji:1f937_200d_2642} about it.
- Space before function, e.g. `a = function ()` is now enforced. I like this because both were fine before.
- I added `eslint-config-prettier` to the config because otherwise a ton of rules conflict with eslint itself.

Close https://github.com/facebook/flipper/pull/915

Reviewed By: jknoxville

Differential Revision: D20594929

fbshipit-source-id: ca1c65376b90e009550dd6d1f4e0831d32cbff03

desktop/scripts/start-dev-server.ts

@@ -149,7 +149,7 @@ function startAssetServer(
 
   app.use(express.static(staticDir));
 
-  app.use(function(err: any, req: any, res: any, _next: any) {
+  app.use(function (err: any, req: any, res: any, _next: any) {
     knownErrors[req.url] = err;
     outputScreen();
     res.status(500).send('Something broke, check the console!');
@@ -157,7 +157,7 @@ function startAssetServer(
 
   const server = http.createServer(app);
 
-  return new Promise(resolve => {
+  return new Promise((resolve) => {
     server.listen(port, 'localhost', () => resolve({app, server}));
   });
 }
@@ -166,7 +166,7 @@ async function addWebsocket(server: http.Server) {
   const io = socketIo(server);
 
   // notify connected clients that there's errors in the console
-  io.on('connection', client => {
+  io.on('connection', (client) => {
     if (hasErrors()) {
       client.emit('hasErrors', ansiToHtmlConverter.toHtml(buildErrorScreen()));
     }
@@ -178,7 +178,7 @@ async function addWebsocket(server: http.Server) {
     const watchman = new Watchman(path.resolve(__dirname, '..'));
     await watchman.initialize();
     await Promise.all(
-      ['src', 'pkg', 'doctor'].map(dir =>
+      ['src', 'pkg', 'doctor'].map((dir) =>
         watchman.startWatchFiles(
           dir,
           () => {