Use async functions wherever applicable

[raphinesse]

Using the async keyword ensures that a function will always return a Promise. Previously this was achieved by wrapping the function body in return Promise.resolve().then(…) which has a very slight async penalty and can make stack traces harder to read.

Definition of done

For all known asynchronous functions:

• add async keyword
• undo wrapping in Promise.resolve().then(…) if applicable
• undo any explicit result wrapping return Promise.resolve(…) ⮕ return …
• throw errors instead of returning rejections return Promise.reject(new Error(…)) ⮕ throw new Error(…)
• optional: use await & try/catch in the function body instead of traditional promise handling

Task list

Tools/libs

• [ ] cordova-cli
• [ ] cordova-lib
• [ ] cordova-create
• [ ] cordova-fetch (src-only: https://github.com/apache/cordova-fetch/pull/89)
• [ ] cordova-common
• [ ] cordova-serve
• [ ] cordova-js (only the Node.js part)

Platforms (only the Node.js part)

• [ ] cordova-android
• [ ] cordova-browser
• [ ] cordova-ios
• [ ] cordova-windows