tsdown

Building + publishing library packages with tsdown.

MUSTCopy Anchor Link

• Build/publish packages with tsdown. Why: standard ecosystem build.
• Emit ESM + declaration files. Why: consumers need types.
• prepublishOnly builds before publish. Why: never ship stale dist/.
• Export every type used in the public API. Why: DTS generation fails on unexported internal types leaking through re-exports.
• Test-publish a new package name before wiring the repo to it. Why: npm's name-similarity policy REJECTS a short/common single word at publish (403 Package name too similar to existing packages) even though npm view says it is free — the block fires only at publish, so a name that passes availability can still fail. A dashless one-word name has the widest collision surface (leat≈lit/lab/tea1, sigil≈sigil_ both blocked); pick a more distinctive real word (leat→headrace, sigil→escutcheon) and confirm with one throwaway publish before renaming the root, member, repo and every consumer dep.

NEVERCopy Anchor Link

• Never bundle a dep the consumer installs itself. Cost: duplicate/version-conflict in consumer tree.