TS2554
Wrong number of arguments
Expected 2 arguments, but got 1.The compiler’s own words. Not translated — this is the string you pasted into a search box.
The selected call signature requires more arguments than this call supplies.
Reproduction
function pair(a: string, b: number) {} pair('x')
The build asserts this emits exactly this code.
Why the compiler says this
A required parameter is part of the function contract. Omitting it would make the implementation receive `undefined` even though its type says that cannot happen, so the call is rejected before it can break that promise.
Fixes
- 01
function pair(a: string, b: number) {} pair('x', 1)
Supply every required argument when the function genuinely needs both.
- 02
function pair(a: string, b = 0) {} pair('x')
Give the parameter a default when omission has a meaningful, safe interpretation.
Takeaway
Fix the caller when the input is required; change the signature only when the operation truly supports omission.