Return types of some functions are not set to promises, and cause ESLint to throw an error

Environment (please complete the following information):

Node.js version: 16.10.0
NPM version: 7.24.0
Browser name and version: Chrome
Platform name and version: OSX
WebdriverIO version: ^7.11.0
wdio-image-comparison-service version: ^3.1.0

Config of WebdriverIO + wdio-image-comparison-service tsconfig:

"types": [
    "node",
    "@wdio/cucumber-framework",
    "@wdio/devtools-service",
    "expect-webdriverio",
    "webdriverio/async"
],

Describe the bug The return types on some of the functions supplied by types/index.d.ts appear to be incorrect. The one I am currently encountering is for checkFullPageScreen. When writing await browser.checkFullPageScreen('...'), I receive the message

ESLint: Unexpected `await` of a non-Promise (non-"Thenable") value.(@typescript-eslint/await-thenable)

In the index.d.ts file, it has the return type as Result without a promise, while the actual function in webdriver-image-comparison has the return type of Promise<ImageCompareResult | number>.

To Reproduce Steps to reproduce the behavior:

Something like this will show the error if you have ESLint installed:

expect(await browser.checkFullPageScreen('viewer_textbox_default_text')).toEqual(0)

Expected behavior It should not show the error because if the return type supports promises, it will allow it to be awaited.

Log n/a

Additional context n/a

webdriverio / visual-testing

Return types of some functions are not set to promises, and cause ESLint to throw an error #77