No bare as casts

Any bare as in production TypeScript is a signal to stop and work through the decision tree below. Test files (*.test.ts, *.test-d.ts, test/**/*.ts) are exempt — tests use as for stubbing and type assertions and that's fine.

Decision tree

Work through these in order before writing or keeping a cast:

1. Tighten the input type. Can the parameter, generic bound, or return type at the source be made more specific so the cast is unnecessary?
2. Add a runtime check. Can a type predicate (function isUser(x): x is User) narrow the type at runtime, eliminating the cast?
3. Restructure a generic. Can a bound or constraint carry the needed information, making the cast unnecessary?
4. Use satisfies. expr satisfies T checks the type without coercing it and is unaffected by this rule. Prefer it when you want a type-check, not a coercion.
5. Use castAs<T>(value). When the value already satisfies T and the assertion is purely declarative, castAs is the right form.
6. Only if none of the above: use blindCast<T, "Reason">(value). The Reason literal must name the specific compromise in language a reviewer can evaluate.

Import