Prevent keyNotFound error with unknown simulators

[dnicolson]

This pull request prevents the following error when running xcodes runtimes when an "Unknown Platform Simulator" is installed:

Error: keyNotFound(CodingKeys(stringValue: "build", intValue: nil), Swift.DecodingError.Context(codingPath: [_JSONKey(stringValue: "820783CB-C389-4006-B2D2-D063F3FD10A1", intValue: nil)], debugDescription: "No value associated with key CodingKeys(stringValue: \"build\", intValue: nil) (\"build\").", underlyingError: nil))

If one accidentally runs xcrun simctl runtime add with an incompatible pre-iOS 16 Simulator runtime:

xcrun simctl runtime add com.apple.pkg.iPhoneSimulatorSDK15_0-15.0.1.1633542405.dmg

The following error will be displayed:

D: 94DEF0B1-1585-4D71-AB37-98AB08FDD000 <unknown platform> (Unusable - Missing Signature: Error Domain=SimDiskImageErrorDomain Code=3 "Missing Signature" UserInfo={NSLocalizedDescription=Missing Signature, unusableErrorDetail=})

The problem is that it's not immediately obvious that Xcode has still installed the runtime, but with a missing signature state:

And when xcodes runs xcrun simctl runtime list -j, there is no build key resulting in the error:

"820783CB-C389-4006-B2D2-D063F3FD10A1" : {
  "deletable" : true,
  "identifier" : "820783CB-C389-4006-B2D2-D063F3FD10A1",
  "kind" : "Disk Image",
  "path" : "\/Library\/Developer\/CoreSimulator\/Images\/Inbox\/820783CB-C389-4006-B2D2-D063F3FD10A1.dmg",
  "signatureState" : "Missing",
  "sizeBytes" : 5304795932,
  "state" : "Unusable",
  "unusableErrorDetail" : "Error Domain=SimDiskImageErrorDomain Code=3 \"Missing Signature\" UserInfo={NSLocalizedDescription=Missing Signature, unusableErrorDetail=}",
  "unusableErrorMessage" : "Missing Signature",
  "unusableSubstate" : "Missing Signature"
}

This change results in the following xcodes runtimes output:

-- Unknown --
Unknown 0 (Downloaded)

Another approach could be to filter out undecodable runtimes in the RuntimeList class, this actually resulted in more code though.

[StevenSorial]

Nice catch, thank you :)

Another approach could be to filter out undecodable runtimes in the RuntimeList class, this actually resulted in more code though.

I prefer that approach. it doesn't have to be a lot of code, actually, it's less code.

Remove all the installed runtimes with the state unusable, before looping over them, then you can then force-unwrap build, version, and platformIdentifier (and remove the unknown enum case).

I would also add a note at the end with how many unknown runtimes were found, with a suggestion to run xcrun simctl runtime list -j for more info.

Disclaimer: I contributed the runtimes feature but I'm not part of the team, so you might want to wait for their opinion/review.

[dnicolson]

The amount of unknown runtimes is indicated by how many "Unknown" runtimes are listed, it should be comparable to what is in Xcode. It's not ideal that there is a 0 though, but further hacks wouldn't have been nice.

The original approach seemed to require using a custom decoder and possibly filtering out the items unable to be decoded afterward. Or do you mean keeping the optional keys so that the decoding doesn't fail?

[StevenSorial]

Or do you mean keeping the optional keys so that the decoding doesn't fail?

yeah, what i meant is removing the

-- Unknown --
Unknown 0 (Downloaded)

and replacing it at the end with (if more than 0):

Note: Found 1 unknown downloaded runtime(s). For more info run `xcrun simctl runtime list -j`.

you just have to add let unusableCount = installed.removeAll { $0.state == "Unusable" }.count before looping over the installed array, and then you can force-unwrap the newly optional values.

[dnicolson]

I've made those changes, thanks for the input!