Function: createFunctionPrecondition()

createFunctionPrecondition(precondition: FunctionPrecondition, fallback: FunctionFallback): MethodDecorator

Utility to make function preconditions.

// No fallback (returns undefined)
function requireGuild(value: number) {
  return createFunctionPrecondition((message: Message) =>
    message.guild !== null
  );
}

// With fallback
function requireGuild(
  value: number,
  fallback: () => unknown = () => undefined
) {
  return createFunctionPrecondition(
    (message: Message) => message.guild !== null,
    fallback
  );
}

Parameters

Parameter	Type	Description
precondition	FunctionPrecondition	The function that defines whether or not the function should be run, returning the returned value from fallback
fallback	FunctionFallback	The fallback value that defines what the method should return in case the precondition fails

Returns

MethodDecorator

Since

1.0.0

Defined in

utils.ts:73