JavaScript error: “is not a function”

Question

It looks like \"$smth is not a function\" is a very common problem with JavaScript, yet after looking through quite a few threads I still cannot understand what is causing i

Answer 1

I also hit this error. In my case the root cause was async related (during a codebase refactor): An asynchronous function that builds the object to which the "not a function" function belongs was not awaited, and the subsequent attempt to invoke the function throws the error, example below:

const car = carFactory.getCar();
car.drive() //throws TypeError: drive is not a function

The fix was:

const car = await carFactory.getCar();
car.drive()

Posting this incase it helps anyone else facing this error.