Function assertFunction

assertFunction(value: unknown, message?: string): asserts value is AnyFunction
Narrows an unknown value to an AnyFunction if it is type-compatible, or raises an error otherwise.
Parameters
- value: unknown
  The value to test.
- Optionalmessage: string
  The error message to use if value is not type-compatible.
Returns asserts value is AnyFunction

Throws
AssertionFailedError If the value was undefined.
- Defined in narrowing/assert.ts:178