// sample-type-error.ts: THIS FILE CONTAINS ONE DELIBERATE TYPE ERROR.
// Free sample from 99helpers.com/file-types/ts
//
// Use it to see the difference between running and type-checking:
//
//   node sample-type-error.ts   runs, and prints "Total: 1020" (wrong)
//   npx tsx sample-type-error.ts                    same
//   npx tsc --noEmit sample-type-error.ts           rejects it:
//   error TS2345: Argument of type 'string' is not assignable to
//   parameter of type 'number'.
//
// Runtimes only remove the types; only the type checker reads them.

function total(a: number, b: number): number {
  return a + b;
}

// Text from a form field is a string, even when it looks like a number.
const fromForm = "10";

// The deliberate error: a string passed where a number is expected.
// JavaScript then joins "10" and 20 as text instead of adding them.
console.log(`Total: ${total(fromForm, 20)}`);

// The fix: convert first. This line prints "Total: 30".
console.log(`Total: ${total(Number(fromForm), 20)}`);