Convert JS object map to TS

[worksofliam]

Changes

Converts the JS object map to TS. No functionality change.

Checklist

• [x] have tested my change
• [ ] updated relevant documentation
• [x] Remove any/all console.logs I added
• [x] eslint is not complaining
• [ ] have added myself to the contributors' list in CONTRIBUTING.md
• [ ] for feature PRs: PR only includes one feature enhancement.

[worksofliam]

@chrjorgensen Check this out and let me know what you think.