TypeScript Code Review Patterns

Stack-specific rules loaded by dh:code-reviewer when tsconfig.json, *.ts, or *.tsx files are detected.

Strict Mode

tsconfig.json must enable strict: true — this covers noImplicitAny, strictNullChecks, strictFunctionTypes, and others
exactOptionalPropertyTypes: true is required in new projects — prevents undefined from being assigned to optional properties
noUncheckedIndexedAccess: true is required when indexing arrays or records — prevents silent undefined propagation
Any @ts-ignore comment without an accompanying explanation comment is a blocking finding
@ts-expect-error is preferred over @ts-ignore — it fails if the error goes away

any type without an explanatory comment is a blocking finding
Type assertions (as SomeType) without runtime validation at the same boundary are a blocking finding
unknown is the correct type for values from external sources — validate before narrowing, not after
object as a type is not meaningful — use Record<string, unknown> or a specific interface
Non-null assertions (value!) without a comment explaining why null is impossible are a blocking finding