is there a way to create regex patterns to match strings?

[alita-moore]

For example let's say I'm given a list of strings

const strings = [... unknown strings]

and I want to make sure that they start with @ both in runtime and in dev time; it would be helpful to be able to do something like

const strings: MatchinString</^@(?!\s)*/>[] = ["@string", "@string with space", "string_without_@"]
// and then I would get a linting error on "@string with space" and "string_without_@" 

Another use case here would be checking in runtime explicity

function assertMatchingString <T extends string>(maybeMatching: T): asserts T is MatchingString</^@(?!\s)*/> {
    if (!/^@(?!\s)*/.test(maybeMatching)) throw "error";
}

This would be especially useful in a setting where I want to perform code knowing that the strings are in the right format

// assume an inputString

assertMatchingString(inputString);
// now inputString would of the type of regex
someFunction(inputString) // this function would have a similar string definition in its input so that type comparisons can be made

[alita-moore]

nevermind, it looks like this is mostly possible using opaque types

[sindresorhus]

You'll probably want to follow microsoft/TypeScript#41160

[alita-moore]

oh very cool, ya that'd be sweet