functions/assert
Helper functions that have to do with asserting.
Functions
assertDefined()
function assertDefined<T>(value, ...__namedParameters): asserts value is Exclude<T, undefined>
Helper function to throw an error if the provided value is equal to undefined.
This is useful to have TypeScript narrow a T | undefined value to T in a concise way.
Type Parameters
| Type Parameter |
|---|
T |
Parameters
| Parameter | Type |
|---|---|
value | T |
...__namedParameters | [undefined] extends [T] ? [string] : ["The assertion is useless because the provided value does not contain undefined."] |
Returns
asserts value is Exclude<T, undefined>
Defined in
assertNotNull()
function assertNotNull<T>(value, ...__namedParameters): asserts value is Exclude<T, null>
Helper function to throw an error if the provided value is equal to null.
This is useful to have TypeScript narrow a T | null value to T in a concise way.
Type Parameters
| Type Parameter |
|---|
T |
Parameters
| Parameter | Type |
|---|---|
value | T |
...__namedParameters | [null] extends [T] ? [string] : ["The assertion is useless because the provided value does not contain null."] |
Returns
asserts value is Exclude<T, null>