Function validateDefined

validateDefined<T>(value, paramName, defaultValue?): T

If value is undefined, it returns the defaultValue, or throws an exception. Else returns the not-undefined value.

Type Parameters

T

Parameters

value: undefined | T
value to assert if defined
paramName: string
the parameter name used in the error message
OptionaldefaultValue: T
default value when undefined value is passed in

Returns T

defined value

Example

const value1 = undefined;
const value2 = 'validString';
const defaultString = 'defaultString';
const param = 'stringParam';

validateDefined(value1, param, defaultString); // 'defaultString'
validateDefined(value1, param, undefined); // Error: stringParam undefined
validateDefined(value2, param, defaultString); // 'validString'
validateDefined(value2, param, undefined); // 'validString'