Function: assertCondition¶
▸ assertCondition(condition, message?): asserts condition
Helper to apply a TypeScript assertion to subsequent code. TypeScript can infer type information from many expressions, and this helper applies those inferences to all code that follows call to this function.
See https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#assertion-functions
example
function foo(value: string | number) {
assertCondtion(typeof value === 'string');
// TypeScript would otherwise compalin, because `value` could have been number,
// but the above assertion refines the type based on the `typeof` expression.
return value.toUpperCase();
}
Parameters¶
| Name | Type |
|---|---|
condition |
any |
message? |
string |
Returns¶
asserts condition