Stream a bounded CSV or JSON import and report what an importer would actually find in it: the type families each column holds, how much of it is null, which records drift from the declared shape, which object keys are set twice, and what the file's encoding and line endings are.
This walkthrough uses the tool's public README and checked-in example files. Run the command from a repository checkout with Node.js 22+.
Run the checked-in example
node bin/csv-json-import-profiler.mjs --input examples/orders-clean.csvRead the result
A consumer piping stdout must handle an empty stdout on exit 2. A configuration error means the run never had a subject, so there is nothing to report about; emitting a fake report for a run that never started would be worse.