The isScriptURL() method of the TrustedTypePolicyFactory interface returns true if it is passed a valid TrustedScriptURL object.

value

A TrustedScriptURL object.

A booleanthat is true if the object is a valid TrustedScriptURL object.

In the below example the constant url was created by a policy, and therefore isScriptURL() returns true. The second example is an attempt to fake an object, and the third is a string. Both of these will return false when passed to isScriptURL().

const url = policy.createScriptURL("https://example.com/myscript.js");
console.log(trustedTypes.isScriptURL(url)); // true;

const fake = Object.create(TrustedScriptURL.prototype);
console.log(trustedTypes.isScriptURL(fake)); // false

console.log(trustedTypes.isScriptURL("https://example.com/myscript.js")); // false