Reference library

TypeScript guides

Focused, maintained explanations that complement the hands-on TypeScript lesson track.

compiler/errors

Fix Error TS2345: Argument Type Not Assignable

Argument of type X is not assignable to parameter of type Y? Here are the 6 most common causes of TypeScript error TS2345 and the exact fix for each.

For:
TypeScript developers diagnosing call-site type errors
Maintained:
Version context:
TypeScript 5.x and 6.x with strict mode

Related lessons

concepts

TypeScript Utility Types Explained With Examples

Learn every TypeScript utility type: Partial, Pick, Omit, Record, ReturnType and more, with runnable examples and a quick reference table.

For:
TypeScript developers composing reusable object and union types
Maintained:
Version context:
TypeScript 5.x and 6.x standard utility types

Related lessons