Allow building projects lacking Runner.xcworkspace

[chika3742]

Related: #185924

I have ensured that Flutter commands do not throw errors even in projects without Runner.xcworkspace, such as those that have migrated to SwiftPM.

Some migration processes checked for the existence of a workspace, but these do not read or write to the workspace directory and function correctly even if it is absent. While the exact intent is unclear, it is likely that they were checking whether Cocoapods was included in the project.

Also, it was causing an error in buildXcodeProject by not passing scheme and BUILD_DIR as arguments when the workspace did not exist .

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the AI contribution guidelines and understand my responsibilities, or I am not using AI tools.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• I followed the breaking change policy and added Data Driven Fixes where supported.
• All existing and new tests are passing.

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[gemini-code-assist]

Code Review

This pull request removes the requirement for an Xcode workspace during LLDB initialization and Swift Package Manager migrations, allowing these processes to succeed with only the project file. Corresponding tests have been updated to reflect this change. Feedback suggests refactoring the construction of xcodebuild arguments in mac.dart to use a more idiomatic single addAll call with collection-if and spread operators to improve readability.

[gemini-code-assist]

The logic for adding xcodebuild arguments can be simplified and made more idiomatic by using a single addAll call with collection-if and spread operators. This improves readability by grouping all build-related flags together.

  buildCommands.addAll(<String>[
    if (workspacePath != null) ...<String>[
      '-workspace',
      workspacePath.basename,
    ],
    '-scheme',
    scheme,
    if (buildAction !=
        XcodeBuildAction.archive) // dSYM files aren't copied to the archive if BUILD_DIR is set.
      'BUILD_DIR=${globals.fs.path.absolute(buildDirectoryPath)}',
  ]);

References

1. Optimize for readability: Code is read more often than it is written. ^(link)

[chika3742]

I think my code has better readability because this checks a variable declared just before.

[vashworth]

Overall this looks okay, but we wouldn't want it to regress. For example, it's long been an requirement, so someone might add code in the future under that assumption. I think at the very least this will need an integration test.

[chika3742]

@vashworth I have added integration tests. Also, I have updated the code so that macOS projects can be built without xcworkspace as well. Thank you for your review.

[okorohelijah]

@hellohuanlin from triage

[hellohuanlin]

lgtm after minor nits

[hellohuanlin]

the auto-formatter makes this a bit ugly (i misread it on first try). can you make the -workspace and -project path the consistent format?

[hellohuanlin]

Avoid negative flags (hasWorkspace rather than noWorkspace)

[auto-submit]

autosubmit label was removed for flutter/flutter/186239, because - The status or check suite Dashboard Checks has failed. Please fix the issues identified (or deflake) before re-applying this label.