How do you check if self.crypto.randomUUID() is available in Javascript?

Question

I'm building a React app and have a need to generate unique UUIDs. I am trying to use the function randomUUID() from self.crypto. See: https://developer.mozilla.org/en-US/docs/Web/API/Crypto/randomUUID

If I don't want my code to explode if this runs in an unsupported browser, would this be sufficient?

function GenerateGuid() {
    if (self && self.crypto) {
        console.log(self.crypto.randomUUID());
    }
    else {
        console.log("self.crypto not available");
    }
}

GenerateGuid();

Answer 1

You should check for randomUUID to be available as Crypto is release since 2011 and randomUUID since 2021 (see Crypto - Browser compatibility). It is possible that you have a version without randomUUID. Check it via typeof. It returns undefined as a string and therefore fails. I dont see more things to test.

function GenerateGuid() {
    if (self && self.crypto && typeof self.crypto.randomUUID === 'function') {
        console.log(self.crypto.randomUUID());
    }
    else {
        console.log("self.crypto not available");
    }
}

GenerateGuid();

Answer 2

I would use optional chaining to check whether self.crypto.randomUUID exists.

function GenerateGuid() {
    if (self?.crypto?.randomUUID) {
        console.log(self.crypto.randomUUID());
    }
    else {
        console.log("self.crypto not available");
    }
}

GenerateGuid();