E2E test Babel with itself before publishing (#10569)

* Add e2e test using Babel itself

* Make checks run again

scripts/integration-tests/utils/git.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+original_git_branch=`git rev-parse --abbrev-ref HEAD`
+tmp_branch_name="integration-tests-$(date +'%F-%H-%M-%N')"
+original_user_name=`git config user.name`
+original_user_email=`git config user.email`
+
+export GIT_E2E_SETUP="true"
+
+function initializeE2Egit {
+  git checkout -b $tmp_branch_name
+
+  # This is needed by lerna, which commits when publishing
+  git config user.name "Babel E2E Test"
+  git config user.email "babel-e2e@example.com"
+}
+
+function cleanupE2Egit {
+  # Delete release tags
+  git tag -d $(git tag -l "version-e2e-test-*")
+
+  # Checkout the previous branch
+  git checkout -f $original_git_branch
+  git branch -D $tmp_branch_name
+
+  # Restore git user
+  git config user.name "$original_user_name"
+  git config user.email "$original_user_email"
+}