The Git Pre-Commit Hook to Avoid Pushing Only Unit Tests In NodeJs

In NodeJS unit testing frameworks such as mocha/chai, you could add .only after describe or it, so that the specific set of tests are run, which excludes/disables all other tests. For example,

describe.only("I just want to run these tests", function() {
   it("should work", function() {
      expect(1).to.equal(1);
   });
});

Chances are, you might forget to remove the .only before you commit and push. And even worse, the code review may miss this – which in fact will disable all other tests in the Continous Integration process.

So, you can easily add a pre-commit hook check that will give you a nice warning if you try to commit some code that has .only.

# Redirect output to stderr.
exec 1>&2
 
# prevent it.only or describe.only commited
if [ "$allowonlytests" != "true" ] &&
    test $(git diff --cached | grep -E "\b(it|describe).only\("  | wc -l) != 0
then
    cat <<\EOF
Error: Attempt to add it.only or describe.only - which may disable all other tests
 
If you know what you are doing you can disable this check using:
 
    git config hooks.allowonlytests true
EOF
    exit 1
fi
 
exit 0

Save above as filename “pre-commit” (without the quotes) in the folder .git/hooks at your project repository. The script will exit non-zero ONE which indicates a No if there is it.only or describe.only in the diff changes. However, the command/script is smart enough (to use grep with regular expression) that will not trigger the warning if it is followed by // line comment.

You can also disable the warning by using the following: