Michael Dimmitt questions

Michael Dimmitt answers

• 'git cat-file -p <sha1>': "fatal: Not a valid object name" on random objects from .git/objects
• How can I squash a range of git commits together given starting and ending SHA's
• How do I list all folder names that have files changed in Git?
• type for useRef if used with setInterval, react-typescript
• How to source shell script with npm scripts?