Fix TS1203: Replace CommonJS export with ES module exports in type declarations

[Copilot]

TypeScript projects targeting ES modules (module: "nodenext") fail to compile with error TS1203 because index.d.ts uses CommonJS export = cuid2 syntax, which is incompatible with ECMAScript modules.

Changes

• Type declarations (index.d.ts): Replaced namespace declaration with export = with direct named exports for createId, init, getConstants, and isCuid

Before/After

// Before: CommonJS-style (TS1203 error with ES modules)
declare namespace cuid2 {
  export function createId(): string;
  export function init(options?: {...}): () => string;
  export function getConstants(): {...};
  export function isCuid(id: string, options?: {...}): boolean;
}
export = cuid2;

// After: ES module-style
export function createId(): string;
export function init(options?: {...}): () => string;
export function getConstants(): {...};
export function isCuid(id: string, options?: {...}): boolean;

Users can continue importing via named imports (import { createId } from '@paralleldrive/cuid2') or namespace imports (import * as cuid2 from '@paralleldrive/cuid2'). No runtime code changes.

Original prompt

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This section details on the original issue you should resolve

<issue_title>TypeScript Error: TS1203 with export = when targeting ES Modules</issue_title>
<issue_description>I encountered a build error (TS1203) when trying to compile a TypeScript project that uses @paralleldrive/cuid2. This error occurs because the library uses an export = assignment in its declaration file (index.d.ts), which is incompatible with projects targeting modern ECMAScript modules (ESM).

Error Output

node_modules/.bun/@paralleldrive+cuid2@3.0.4/node_modules/@paralleldrive/cuid2/index.d.ts:22:1 - error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.

22 export = cuid2;
   ~~~~~~~~~~~~~~~

Steps to Reproduce

1. Set up a new TypeScript project.
2. Ensure tsconfig.json is configured to target ES Modules (e.g., "module": "nodenext").
3. Install the package: npm install @paralleldrive/cuid2.
4. Import the package in a TypeScript file:

   import { createId } from '@paralleldrive/cuid2';

5. Attempt to compile the project using npx tsc -b.

Potential Fix

To resolve this for users targeting ES Modules, consider replacing the export = cuid2; line in the declaration file with the more modern and compatible export default cuid2; format.

This change would allow projects using modern module configurations to build without requiring them to set skipLibCheck: true in their tsconfig.json.

Environment

• Package Version: @paralleldrive/cuid2@3.0.4
• TypeScript Version: 5.9.3
• Node.js: 24.11.1
• Relevant tsconfig.json settings:

  {
    "compilerOptions": {
      "target": "es2024",
      "module": "nodenext",
    }
  }
  ```</issue_description>
  

<agent_instructions>Could you take a look, validate, and fix if required? Please ensure that typescript runs without error prior to PR.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes TypeScript Error: TS1203 with export = when targeting ES Modules #114

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Note

Modernizes the type declarations for ESM compatibility and fixes TS1203.

• Replace namespace + export = with top-level named exports for createId, init, getConstants, and isCuid in index.d.ts
• No runtime changes; public API shape via named imports remains the same

^{Written by Cursor Bugbot for commit a910d6e. This will update automatically on new commits. Configure here.}

[ericelliott]

@cursoragent please /review and be sure to test the import in your sandbox to make sure it works with the typescript compiler

[cursor]

Review Complete ✅

I've thoroughly reviewed and tested the TypeScript TS1203 fix. Here's what I validated:

Type Declaration Changes

The index.d.ts file correctly uses ES module exports instead of the incompatible CommonJS export = syntax. All function signatures are properly typed and match the runtime implementation.

TypeScript Compilation Tests

• ✅ Compiles successfully with module: "nodenext" (the configuration that triggered TS1203)
• ✅ No TS1203 errors when targeting ES modules
• ✅ Type declarations are syntactically correct

Import Pattern Validation

Tested and verified both import patterns work correctly:

// Named imports
import { createId, init, getConstants, isCuid } from '@paralleldrive/cuid2';

// Namespace imports
import * as cuid2 from '@paralleldrive/cuid2';

Runtime Verification

Created and ran comprehensive runtime tests confirming:

• All four exported functions work correctly
• Function signatures match type declarations
• Optional parameters behave as expected
• Both import patterns produce identical results

Quality Assurance

• ✅ All existing unit tests pass (23/23 tests)
• ✅ CLI tests pass (10/10 tests)
• ✅ Lint checks pass
• ✅ No breaking changes introduced
• ✅ Backward compatible with existing usage

The fix is production-ready and resolves the reported issue while maintaining full compatibility with existing code.