[pjcdawkins]

TestAuthRefresh_ManyExpiries failed on Windows in a CI run of #272 (it passed on a re-run):

open …\.platform-test-cli\auth\default.json: The process cannot access the file because it is being used by another process.

With Go auth, the file store replaces a session file with a rename, which WriteFileAtomic retries on Windows while another process has the file open. Reads of the file, outside the lock, had no retry, so a command that read it during a rename failed with a sharing violation. Reads now retry on a sharing violation, as the rename does (store.ReadFile). The migration marker, the other file that WriteFileAtomic writes, is read the same way.

TestReadFileWhileReplaced (Windows only) reads a file while it is replaced 500 times. Run in a Windows 11 VM, 10–19 plain reads failed in each run, and none with the retry. CI runs Go unit tests on Linux only, so it doesn't run there.

🤖 Generated with Claude Code

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Warning

Changes suggested — 🟡 1 warning

🔍 Full review · 4 files reviewed

Verification

• readFile returns the error unchanged once the error is not a sharing violation, so readSessionFile still maps fs.ErrNotExist to (nil, nil).
• The read retry has the same bounds as the rename retry in WriteFileAtomic: 41 attempts with 25ms sleeps.
• sharing_windows.go and sharing_windows_test.go are limited to Windows by their _windows file-name suffix, and sharing_other.go has the matching !windows tag. golang.org/x/sys is already a direct requirement in go.mod.
• The test uses sync.WaitGroup.Go, which is supported by the module's go 1.27.1 directive.

The only coverage is the new TestReadFileWhileReplaced, which is Windows-only. Per the PR description, CI runs the Go unit tests on Linux only, so no automated check runs this test or reaches the retry branch.

Review details

• Commit: 653915a
• Model: claude-opus-5-5

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