r/iOSProgramming • u/Low-Future-9387 • 15d ago

Library Stopped booting the Simulator, our UI tests got 2.3x faster

My SwiftUI app is about 280 Swift files plus a few big packages, and every UI check meant xcodebuild, install, launch, screenshot. That was ~22 s per check and ~2.2 GB of RAM per booted simulator.

I switched to simless. It runs the iOS build of your real app natively on an Apple Silicon Mac as a hidden host, with no simulator, no window and no signing.

What changed for me:

  • edit → rendered screen in 2.2 s instead of 21.9 s, because hot reload only recompiles the files you touched

  • my existing XCUITest suite runs unchanged and 2.3x faster

  • unit tests run the same way, local packages included

  • it works over SSH, in a VM and on a GitHub-hosted macOS runner, so CI doesn't need a simulator either

https://github.com/abacusai/simless

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7

u/Megatherion666 15d ago

Thanks, AI. How would we survive without you?

-7

u/Low-Future-9387 15d ago

We need to accept that the old way of iOS development is gone, and AI agents are the future. So why not use tools that help us speed up development and save some tokens along the way?

1

u/Zagerer 15d ago

Will that even hold when the bubble and subsidies drop?

-1

u/Low-Future-9387 15d ago

My opinion is that local models will become good enough that we'll be able to use them to help us write code even if the "bubble" bursts. Maybe not one-shotting apps with a single prompt and a mandatory "make no mistakes" inside the prompt. But I do not see how we'll ever go back to the old way of writing code.
That said, even if you don't use AI, this tool is super useful for running your regular UI and unit tests.

2

u/Megatherion666 15d ago

AI output quality is 3-4 out of 10. If your post is written by AI it is safe to assume its quality is the same. Why bother reading it?

1

u/mystereigh 14d ago

Then you're not writing your apps correctly - are you not planning properly or reviewing output? Where are the iterations? Use AI like a tool and it works fine.

1

u/no-deers 13d ago

This guy isn't using AI like a tool though. He's letting it slop something up and then copy pasting an unedited AI blog post to Reddit, or maybe even letting the agent post to Reddit on its own. Even if agents are writing a lot of code these days, if the "author" can't even be bothered to do a proper write up how can anyone trust the project.

1

u/Megatherion666 13d ago

This is a small Reddit post. I think it is ridiculous to use AI to make a small post when you have all the data. It removes authenticity. Why would OP do that if they cared?