isinvocabler

isinvocabler is a JavaScript function that checks if a given value is an invocable (callable) entity. In JavaScript, an invocable entity is something that can be invoked or called using the function call operator `()`. This typically refers to functions, but can also include objects that have a `Symbol.toPrimitive` method that returns a function or a `call` method.

The primary purpose of isinvocabler is to provide a reliable way to determine if a variable holds something that can be executed as a function, preventing potential runtime errors that could occur if an attempt is made to call a non-function value. This is particularly useful in scenarios where functions might be passed as arguments or stored in data structures, and their type needs to be validated before execution.

The function typically returns a boolean value: `true` if the input is invocable, and `false` otherwise. It is often used in libraries or frameworks to ensure that callbacks or event handlers are valid before being invoked. Its implementation usually involves checking the `typeof` the value, looking for specific properties or methods that indicate callability, and handling edge cases such as `null` or `undefined`.