Parse Dont Validate

Parse, Don't Validate

Do not merely check data and then throw the proof away. Parse it into a type that carries the proof.

Workflow

1. Find validators that return bool, void, or throw while leaving the original untyped value in circulation.

2. Define a target type whose construction proves the invariant.

3. Replace validation calls with parser or smart-constructor calls that return Result, Either, option, or exceptions as appropriate for the language.

4. Change downstream APIs to accept the parsed type.

5. Remove redundant re-validation.

Checks

• A parsed type should make invalid states unrepresentable.

• Keep boundary parsing near input edges.

• Preserve error detail for users and logs.

Reference

Read references/patterns.md for language patterns.

Detailed Reference

For non-trivial implementation, review, or refactoring work, read references/details.md before giving final guidance. It contains the detailed rules, examples, smells, and migration notes that do not belong in the short invocation body.

Output

Return the current validation leak, parsed type design, API changes, and migration steps.