Typings error for ElementArrayFinder.filter in v5.1.0

[massimocode]

Looking at this commit:
995b146

This typing is incorrect:

filter(
      filterFn: (element: ElementFinder, index?: number) => boolean |
          wdpromise.Promise<boolean>): ElementArrayFinder {

It should be:

filter(
      filterFn: (element: ElementFinder, index?: number) => boolean |
          PromiseLike<boolean>): ElementArrayFinder {

The current typing breaks the following lines of code:

element.all(by.className("blah")).filter(async row => (await row.$$(".ng-binding").get(0).getText()) === "foo");

The error is:

error TS2345: Argument of type '(row: ElementFinder) => Promise<boolean>' is not assignable to parameter of type '(element: ElementFinder, index?: number) => boolean | Promise<boolean>'.
  Type 'Promise<boolean>' is not assignable to type 'boolean | Promise<boolean>'.
    Type 'Promise<boolean>' is not assignable to type 'webdriver.promise.Promise<boolean>'.

I think the same applies to the other places where it is written T | wdpromise.Promise<T>
For example ElementArrayFinder.get

[jan-molak]

Indeed, I provided some more details in #4049

[sjelin]

Closing as duplicate. I talk specifically about async/await issues in #4049 (comment)