A brand new Xcode project folder will be created, and Xcode will be automatically launched to open the new project.
The Xcode project will be linked to the source web extension folder, so you need to make sure both source and generated folder exist and have a consistent relative path.
Without doing anything further in Xcode, just click run to launch the extension
Safari will be opened, yet extension will not appear at first sight. You need to do the following steps first: a. safari -> preferences -> enable development menu
b. safari -> develop menu -> click allow unsigned extension (need to do this every time safari is restarted)
Go to Xcode, click Project -> target -> app target, update app category and bundle identifier (use the one in the App Store)
Click extension target of project, update bundle identifier. Note the the project identifier should prefix the extension identifier. E.g. if project identifier is ‘hk.com.bart.simplegmailnotes’, then extension identifier should be something like ‘hk.com.bart.simplegmailnotes.extension’
In Xcode -> assets -> make sure all icons are provided
Update the extension name in the swift file of app
In Xcode click Product -> Archive
Distribute window should automatically appear after the archive action. (If not, click Window -> Organize -> Distribute App)
Select App Store Connect
Open a browser, go to App store connect, click the app, and now you should be able to select the build
(If the build is not available, check your App Store email and see if there are any error reports.)
Upload all the screenshots and add descriptions to App Store Connect
You are now good to start a review process, good luck :)
Update 2020-12-30: After a few weeks of back and forth, we finally launched the app into Mac Extension Store. Some major comments from Apple:
Cannot have any donation related content, unless you are a non-profit organization
Cannot have any payment, unless via Apple gateway
Cannot mention COVID 19, unless you are officially granted
Extension name must be changed from ‘Simple Gmail Notes’ to ‘Simple Notes for Gmail’