Questions tagged [typeguards]
Inquiries are welcome regarding the utilization of predefined (such as "instanceof", "typeof", and "in" operators) or user-defined guards for narrowing types.
After exploring the reorderable columns demo on stackblitz, I came across this interesting code snippet. Specifically, here is the HTML snippet: <table mat-table [dataSource]="dataSource" cdkDropList cdkDropListOrientati ...
There are instances where I find myself needing to perform type checks on variables within a function before proceeding further. Personally, I try to minimize nesting in my code and often utilize early-return statements to keep the main functionality of a ...
Here is an example of some code I'm working on: type DataType = { name: string, age: number, } | { xy: [number, number] } function processInput(input: DataType) { if (input.name && input.age) { // Do something } else i ...
I'm currently working on refining a generic function, where the autocomplete feature recognizes that it's encountering a typeguard, preventing it from revisiting the same code block. I suspect that the issue lies in not restricting the type to th ...
Is it possible to create a typeguard that can confirm the existence (or specific type) of a property in an object? For example: Consider an interface Foo: interface Foo { bar: string; baz: number; buzz?: string; } An object of type Foo may ...
Is there a way to restrict the type of property of a class in an aliased conditional expression? Short: I am trying to perform a type narrowing check within a class method, like this._end === null && this._head === null, but I need to assign the r ...