Dealing with yarn.lock file merge conflicts - AndelaOSP/Andela-Socials GitHub Wiki
When resolving merge conflicts between the develop branch and feature branch you would need to rebase
git rebase origin/develop
If there is a conflict with the yarn.lock file, checkout the yarn.lock then re-perform the installation
git checkout origin/develop -- yarn.lock
yarn install
This generates a new yarn.lock based on the origin/develop version of yarn.lock, but including the changes you made to your package.json. Then it's just a matter of:
git add yarn.lock
git rebase --continue