chore(codemods): Convert from CJS to ESM

[Tobbe]

This is safe as no one imports this package. It's always run as a bin

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☁️ Nx Cloud last updated this comment at 2026-03-04 09:31:53 UTC

[greptile-apps]

Greptile Summary

This PR converts the @cedarjs/codemods package from CommonJS to ESM by updating package.json to "type": "module", switching the build tool to buildEsm, and making all the mechanical code changes required (.js extensions on local imports, __dirname → import.meta.dirname, ESM-compatible yargs imports, explicit jscodeshift/src/Runner.js path). The migration is safe since the package is consumed only as a CLI binary and never imported by other packages.

Key changes verified:

• package.json: "type": "commonjs" → "type": "module"; build.mts switches to buildEsm()
• All local imports gain explicit .js extensions as required by Node.js ESM resolution
• All __dirname references replaced with import.meta.dirname (requires Node.js ≥ 20.11.0)
• yargs entrypoint updated from the CJS default export to the ESM-compatible yargs/yargs factory pattern with hideBin(process.argv)
• New tsconfig.build.json added with "module": "node20" / "moduleResolution": "node16", consistent with other packages in the monorepo (e.g. cli)
• Code-generation templates updated so any newly-generated codemods are immediately ESM-compliant
• Test utilities correctly updated with .js extensions; require.resolve() usage in test files is appropriate in vitest test environments

Confidence Score: 5/5

• This PR is safe to merge — it is a clean, mechanical CJS-to-ESM migration with no behavioural changes.
• All changes are consistent and follow the same pattern used by other ESM packages in the monorepo. The yargs ESM idiom is correct, import.meta.dirname is the proper replacement for __dirname, and explicit .js extensions are required by Node.js ESM. The code has been tested and passes CI. No new issues introduced.
• No files require special attention.

_{Last reviewed commit: aa0f279}

[github-actions]

The changes in this PR are now available on npm.

Try them out by running yarn cedar upgrade -t 3.0.0-canary.13512