fix: emit non-empty types for nativewind/preset - #1784

Summary

Fixes #1330.

packages/nativewind/src/tailwind/index.ts uses module.exports = Object.assign(...), a pattern TypeScript's declaration emit can't handle — the published package ships an empty dist/tailwind/index.d.ts. Users importing nativewind/preset under checkJs: true (or from *.ts files) hit TS2306: File '.../dist/tailwind/index.d.ts' is not a module.

@danstepanov confirmed the root cause in #1330 (comment):

The published npm package has an empty (0 byte) dist/tailwind/index.d.ts. The source file (src/tailwind/index.ts) uses module.exports = Object.assign(...) which TypeScript's declaration emit can't generate types for.

Fix

Switch to the canonical TS-compatible CJS pattern:

const preset = Object.assign(
  () => { /* ... */ },
  { nativewind: true as const },
);

export = preset;

• tsc --declaration emits a non-empty .d.ts for export = X.
• The compiled .js still emits module.exports = preset — identical runtime shape, no breaking change for consumers.
• as const narrows nativewind: true to a literal type, matching the manual workaround users have been writing via module augmentation.

Verification

Before fix: dist/tailwind/index.d.ts is 0 bytes.

After fix: dist/tailwind/index.d.ts contains:

declare const preset: (() => any) & {
    nativewind: true;
};
export = preset;

Compiled dist/tailwind/index.js is runtime-equivalent (module.exports = preset with the same callable + nativewind: true property).

Tests

npm test passes — 784/784 tests across 30 suites, no regressions.