CircleCI project setup (#138)

scripts/assert-changed-files.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+IS_CI="${CI:-false}"
+GREP_PATTERN=$1
+
+if [ "$IS_CI" = true ]; then
+  git config --local url."https://github.com/".insteadOf git@github.com:
+  git config --local user.name "Medusajs Bot"
+  git config --local user.email "core@medusa-commerce.com"
+
+  git fetch origin
+  git merge --no-edit origin/master
+
+  if [ $? -ne 0 ]; then
+    echo "Branch has conflicts with master, rolling back test."
+    git merge --abort
+  fi
+
+  git config --local --unset user.name
+  git config --local --unset user.email
+  git config --local --unset url."https://github.com/".insteadOf
+fi
+
+FILES_COUNT="$(git diff-tree --no-commit-id --name-only -r "$CIRCLE_BRANCH" origin/master | grep -E "$GREP_PATTERN" -c)"
+
+# reset to previous state
+git reset --hard HEAD@{1}
+
+if [ "$FILES_COUNT" -eq 0 ]; then
+  echo "0 files matching '$GREP_PATTERN'; exiting and marking successful."
+  circleci step halt || exit 1
+else
+  echo "$FILES_COUNT file(s) matching '$GREP_PATTERN'; continuing."
+fi