fix: wait for webpack builds to finish

in the current setup, webpack builds where still running when the
puppeteer tests would start, which leads to timeout issues,
especially on slow machines like CI servers.

This commit waits for the build to finish before continuing with
`getUrl`, which is called by the integration tests upfront

Co-authored-by: Björn Brauer <bjoern.brauer@new-work.se>

packages/jest-environment/helpers.js

@@ -45,8 +45,11 @@ const build = ({ cwd, env = {}, argv = [] }) =>
 const startServer = ({ cwd, command, env = {}, argv = [] }) => {
   const teardownPromise = new EProm();
   const urlPromise = new EProm();
+
   let stdout = '';
   let stderr = '';
+  const success1 = "bundling 'develop' finished";
+  const success2 = "bundling 'node' finished";
 
   const hopsBin = resolveFrom(cwd, 'hops/bin');
   const args = [hopsBin, command].concat(argv);
@@ -61,15 +64,20 @@ const startServer = ({ cwd, command, env = {}, argv = [] }) => {
     return teardownPromise;
   };
 
+  let serverUrl = '';
   started.stdout.on('data', (data) => {
     const line = data.toString('utf-8');
     debug('stdout >', line);
     stdout += line;
 
     const [, url] = line.match(/listening at (.*)/i) || [];
     if (url) {
+      serverUrl = url;
       debug('found match:', url);
-      urlPromise.resolve(url);
+    }
+
+    if (stdout.includes(success1) && stdout.includes(success2) && serverUrl) {
+      urlPromise.resolve(serverUrl);
     }
   });