xctestrunner incorrectly handles maxRuntimeVersion (15.255.255 → 15.3)

[bc-lee]

Summary

xctestrunner incorrectly parses the maxRuntimeVersion of iPhone 6s Plus (and similar devices) as 15.3, which makes it impossible to create a simulator with iOS 15.5.

Steps to Reproduce

Run following command on the valid bazel project:

bazel test --ios_simulator_device='iPhone 6s Plus' --ios_simulator_version=15.5

Actual Behavior

The test runner fails with:

Traceback (most recent call last):
  File "/path/to/bazel//a59b5fbd1ac4fd988fa8e6c30761d359/sandbox/darwin-sandbox/487/execroot/_main/bazel-out/darwin_arm64-fastbuild/bin/Tests/Foundation/NSData_zlibTests/NSData_zlibUnitTest.runfiles/_main/../rules_apple++non_module_deps+xctestrunner/xctestrunner/test_runner/ios_test_runner.py", line 319, in <module>
    sys.exit(main(sys.argv))
             ^^^^^^^^^^^^^^
  File "/path/to/bazel//a59b5fbd1ac4fd988fa8e6c30761d359/sandbox/darwin-sandbox/487/execroot/_main/bazel-out/darwin_arm64-fastbuild/bin/Tests/Foundation/NSData_zlibTests/NSData_zlibUnitTest.runfiles/_main/../rules_apple++non_module_deps+xctestrunner/xctestrunner/test_runner/ios_test_runner.py", line 313, in main
    exit_code = args.func(args)
                ^^^^^^^^^^^^^^^
  File "/path/to/bazel//a59b5fbd1ac4fd988fa8e6c30761d359/sandbox/darwin-sandbox/487/execroot/_main/bazel-out/darwin_arm64-fastbuild/bin/Tests/Foundation/NSData_zlibTests/NSData_zlibUnitTest.runfiles/_main/../rules_apple++non_module_deps+xctestrunner/xctestrunner/test_runner/ios_test_runner.py", line 216, in _SimulatorTest
    return _RunSimulatorTest(args)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "/path/to/bazel//a59b5fbd1ac4fd988fa8e6c30761d359/sandbox/darwin-sandbox/487/execroot/_main/bazel-out/darwin_arm64-fastbuild/bin/Tests/Foundation/NSData_zlibTests/NSData_zlibUnitTest.runfiles/_main/../rules_apple++non_module_deps+xctestrunner/xctestrunner/test_runner/ios_test_runner.py", line 186, in _RunSimulatorTest
    simulator_id, _, os_version, _ = simulator_util.CreateNewSimulator(
                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/path/to/bazel//a59b5fbd1ac4fd988fa8e6c30761d359/sandbox/darwin-sandbox/487/execroot/_main/bazel-out/darwin_arm64-fastbuild/bin/Tests/Foundation/NSData_zlibTests/NSData_zlibUnitTest.runfiles/rules_apple++non_module_deps+xctestrunner/xctestrunner/simulator_control/simulator_util.py", line 358, in CreateNewSimulator
    _ValidateSimulatorTypeWithOsVersion(device_type, os_version)
  File "/path/to/bazel//a59b5fbd1ac4fd988fa8e6c30761d359/sandbox/darwin-sandbox/487/execroot/_main/bazel-out/darwin_arm64-fastbuild/bin/Tests/Foundation/NSData_zlibTests/NSData_zlibUnitTest.runfiles/rules_apple++non_module_deps+xctestrunner/xctestrunner/simulator_control/simulator_util.py", line 654, in _ValidateSimulatorTypeWithOsVersion
    raise ios_errors.IllegalArgumentError(
xctestrunner.shared.ios_errors.IllegalArgumentError: The max OS version of iPhone 6s Plus is 15.300000. But current OS version is 15.5
error: tests exited with '1

Root Cause

This happens because xctestrunner/simulator_control/simtype_profile.py does not handle special maxRuntimeVersion patterns correctly. On my machine:

$ xcrun simctl list devicetypes -j | python3 -c "
import json, sys
data = json.load(sys.stdin)
iphone_devices = [d for d in data['devicetypes'] if d['name'].startswith('iPhone')]

print('iPhone Runtime Version Analysis:')
print('=' * 50)
for device in iphone_devices:
    max_runtime = device.get('maxRuntimeVersionString', 'unlimited')
    print(f'{device[\"name\"]:30} Max Runtime: {max_runtime}')
"

shows:

iPhone Runtime Version Analysis:
==================================================
iPhone 16 Pro                  Max Runtime: 65535.255.255
iPhone 16 Pro Max              Max Runtime: 65535.255.255
iPhone 16e                     Max Runtime: 65535.255.255
iPhone 16                      Max Runtime: 65535.255.255
iPhone 16 Plus                 Max Runtime: 65535.255.255
iPhone 15 Pro                  Max Runtime: 65535.255.255
iPhone 15 Pro Max              Max Runtime: 65535.255.255
iPhone 15                      Max Runtime: 65535.255.255
iPhone 15 Plus                 Max Runtime: 65535.255.255
iPhone 14 Pro                  Max Runtime: 65535.255.255
iPhone 14 Pro Max              Max Runtime: 65535.255.255
iPhone 14                      Max Runtime: 65535.255.255
iPhone 14 Plus                 Max Runtime: 65535.255.255
iPhone SE (3rd generation)     Max Runtime: 65535.255.255
iPhone 13 Pro                  Max Runtime: 65535.255.255
iPhone 13 Pro Max              Max Runtime: 65535.255.255
iPhone 13                      Max Runtime: 65535.255.255
iPhone 13 mini                 Max Runtime: 65535.255.255
iPhone 12 Pro                  Max Runtime: 65535.255.255
iPhone 12 Pro Max              Max Runtime: 65535.255.255
iPhone 12                      Max Runtime: 65535.255.255
iPhone 12 mini                 Max Runtime: 65535.255.255
iPhone SE (2nd generation)     Max Runtime: 65535.255.255
iPhone 11 Pro                  Max Runtime: 65535.255.255
iPhone 11 Pro Max              Max Runtime: 65535.255.255
iPhone 11                      Max Runtime: 65535.255.255
iPhone Xʀ                      Max Runtime: 18.99.0
iPhone Xs                      Max Runtime: 18.99.0
iPhone Xs Max                  Max Runtime: 18.99.0
iPhone X                       Max Runtime: 16.9.0
iPhone 8                       Max Runtime: 16.9.0
iPhone 8 Plus                  Max Runtime: 16.9.0
iPhone 7                       Max Runtime: 15.255.255
iPhone 7 Plus                  Max Runtime: 15.255.255
iPhone SE (1st generation)     Max Runtime: 15.255.255
iPhone 6s                      Max Runtime: 15.255.255
iPhone 6s Plus                 Max Runtime: 15.255.255

Considering the model's last supported iOS versions, the following patterns are used:

• 65535.255.255 → effectively unlimited
• 18.99.0 → upper bound pattern
• 15.255.255 → upper bound pattern

However, xctestrunner truncates these values incorrectly, causing 15.255.255 to be parsed as 15.3.

Expected Behavior

• iPhone 6s Plus should be treated as supporting up to iOS 15.x, so requesting 15.5 should succeed.
• Special version encodings like 255.255, 99.0, or 65535.255.255 should be parsed as upper limits, not literal decimal values.