Pure Ts Fix -

// Partial: Make all properties optional function updateTodo(todo: Todo, fieldsToUpdate: Partial<Todo>) return ...todo, ...fieldsToUpdate ;

"Pure TypeScript" refers to using TypeScript in its most straightforward form — without frameworks, libraries, or complex build toolchains. The code is written in .ts files, compiled with the TypeScript compiler ( tsc ), and run as plain JavaScript. pure ts

Start simple, keep strict on, and let the types guide your code. ) return ...todo

type SuccessState = status: 'success'; data: string ; type ErrorState = status: 'error'; error: string ; keep strict on

// Tuple (Fixed structure) let x: [string, number]; x = ["hello", 10]; // OK // x = [10, "hello"]; // Error