Updated Review guidelines (markdown)

Review-guidelines.md

@@ -19,6 +19,7 @@
 * Every PR should change/fix **exactly one thing**. Otherwise, ask the author to split to smaller PRs.
 ### 4. Verify **the fix solves the issue properly.**
 * It is usually good practice to clone the branch and try it out yourself.
+* Tests ar passing but something breaks when you try running locally? That means we are missing a test case. Ask author to add a test case/add it yourself.
 ### 5. Verify the code is **correct and readable**.
 * Code is read way more often than it is written or modified, so readability is always important. You should aim to understand every changed line. If you don't understand it, it's likely someone else won't either. Ask questions and comments for things you don't understand.
 * Make sure error scenarios and edge cases are well handled.