Build a Small JavaScript Library with ES Module Exports

Putting C3 together

You'll design a single inline module that demonstrates the export shape a real library ships:

1. A default export — the main thing the library is about.
2. A few named exports — secondary utilities.
3. No side effects — nothing runs at import time; just declarations.

Then "consume" the library in the same module by simulating the import + usage flow.

Library design tip

When you ship a library, every named export is a commitment — once published, removing or renaming it is a breaking change. Default exports are easier to evolve (you control the importer's local name). Most libraries land on:

• Default = the main entry point.
• Named = a curated 3-10 utilities.
• Anything else stays internal.

The capstone

Build a tiny "format" library: default export is format (takes a Date, returns ISO string); named exports are formatDate (just YYYY-MM-DD) and formatTime (just HH:MM). Then consume all three and log them.