Reproduction of date-fns & parcel issue building and running typescript code

Working example

To showcase working example in plain javascript do the following:

1. In index.html uncomment script ./formatImport.js alone
2. Run npm run start
3. Go to localhost:8080
4. Dev server works perfectly
5. Run npm run build
6. Run npm run start:prod
7. Go to localhost:8080
8. Prod server works perfectly

Reproduce issue

To reproduce the issue do the following:

1. In index.html uncomment script ./formatImport.ts alone
2. Run npm run start
3. Go to localhost:8080
4. Dev server throws error runtime
5. Run npm run build
6. Build fails with error
7. In index.html uncomment script ./formatImportDate.ts alone
8. Run npm run start
9. Go to localhost:8080
10. Dev server throws error runtime
11. Run npm run build
12. Run npm run start:prod
13. Go to localhost:8080
14. Prod server works perfectly