Function: ensureUnreachable¶
core.ensureUnreachable
▸ ensureUnreachable(value
, message?
): never
Helper for TypeScript to make sure that handling of code forks is exhaustive,
most commonly with a switch
statement.
Example
enum MyEnum {
Foo = 'Foo',
Bar = 'Bar',
}
function handleEnum(value: MyEnum) {
switch(value) {
case MyEnum.Foo:
return 'foo';
case MyEnum.Bar:
return 'bar';
default:
// This code is unreachable since the two cases above are exhaustive.
// However, if a third value were added to MyEnum, TypeScript would flag
// an error at this line, informing you that you need to update this piece of code.
return ensureUnreachable(value);
}
}
Parameters¶
Name | Type |
---|---|
value |
never |
message? |
string |
Returns¶
never