Pass deep link into iOS Simulator?

You can type this into your Terminal :

xcrun simctl openurl booted '<INSERT_URL_HERE>'

You can even share documents using the builtin Share Extension from the Finder to the iOS Simulator.

Here's another approach:

In the Simulator

1. Open the Contacts app
2. Go to one of the pre-defined contacts, like "John Appleseed"
3. Tap Edit
4. Tap add url (at the bottom) - and set your link as a "homepage" URL for this contact
5. Tap Done to save the contact
6. Tap on the link you just added

Pro tip: You can add custom labels to the URL entries, for example if you want to test different URLs and be able to identify them quickly.

Note: If you reset the Simulator, the Contacts app will be reset to default and lose the URL.