rc-js-util
Version:
A collection of TS and C++ utilities to help writing performant and correct applications, achieved through strict typing and (removable) invariant checking.
67 lines (37 loc) • 1.09 kB
Markdown
<!-- Do not edit this file. It is automatically generated by API Documenter. -->
[Home](./index.md) > [rc-js-util](./rc-js-util.md) > [\_Production](./rc-js-util._production.md) > [assertValueIsNever](./rc-js-util._production.assertvalueisnever.md)
## \_Production.assertValueIsNever() method
A function that will error if ever called. The parameter is asserted to be never, useful with switch statements, union types etc.
**Signature:**
```typescript
static assertValueIsNever(_value: never): never;
```
## Parameters
<table><thead><tr><th>
Parameter
</th><th>
Type
</th><th>
Description
</th></tr></thead>
<tbody><tr><td>
\_value
</td><td>
never
</td><td>
</td></tr>
</tbody></table>
**Returns:**
never
## Example
```typescript
// adding extra values to the enum will cause a compiler error
enum ETest { Foo = 1 };
function test(value: ETest)
{
switch (value) {
case ETest.Foo: return "potato";
default: return _Production.assertValueIsNever(value);
}
}
```