test(fs): cover recursive mkdir options-object decoding

[proggeramlug]

Summary

Adds an end-to-end regression test for the fs.mkdirSync(path, { recursive: true }) options-object crash fixed in #8204. Claude Code exercises this exact call during normal startup, while its --version fast path exits before reaching it.

Changes

• Compile and run a minimal TypeScript program that passes an options object to recursive mkdirSync.
• Assert that the nested directory is created and the native program exits successfully.
• Document how the old fs string helper misread an object header as a StringHeader and attempted a roughly 2 GiB copy.

Related issue

Follow-up to #8204; refs #8122.

Test plan

• cargo build --release clean (not run; test-only change)
• cargo test --workspace --exclude perry-ui-ios --exclude perry-ui-tvos --exclude perry-ui-watchos --exclude perry-ui-gtk4 --exclude perry-ui-android --exclude perry-ui-windows passes (not run)
• rustfmt --edition 2024 --check crates/perry/tests/issue_8122_fs_mkdir_options_object.rs
• git diff --cached --check
• Compiled and ran the same reproducer with the corrected release runtime and PERRY_GC_VERIFY_EVACUATION=1: PASS, exit 0
• Added a user-facing regression test in the affected crate
• Updated docs/src/ (not applicable; no API or behavior change)
• Built a platform UI backend (not applicable)

The focused Cargo invocation was also attempted on Windows. It currently stops while compiling clean main because native_stack_scan.rs references Unix-only libc::Dl_info / libc::dladdr; it does not reach this test. Workspace-wide cargo fmt likewise hits Windows path error 206, while the new file passes standalone rustfmt.

Screenshots / output

Wrote executable: claude-code-build\repro-mkdir-options.exe
PASS
RUN_EXIT=0

Checklist

• I have NOT bumped the workspace version or edited CLAUDE.md / CHANGELOG.md (maintainer handles these at merge)
• My commit follows the repository's conventional prefix style
• I've read CONTRIBUTING.md and agree to the Code of Conduct

Summary by CodeRabbit

• Bug Fixes

  • Fixed an issue where fs.mkdirSync could crash when called with an options object containing recursive: true.
  • Recursive directory creation now works correctly with nested paths.

• Tests

  • Added regression coverage validating directory creation, execution success, and cleanup.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 96d92bb3-65d1-496d-8622-147e71afc08f

📥 Commits

Reviewing files that changed from the base of the PR and between 280aafe and 0423751.

📒 Files selected for processing (2)

• changelog.d/8309-mkdir-options-object-regression.md
• crates/perry/tests/issue_8122_fs_mkdir_options_object.rs

Included review availability: Your plan includes up to 8 reviews per rolling hour; 2 remain after this review.

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📝 Walkthrough

Walkthrough

Adds an end-to-end regression test for recursive fs.mkdirSync calls with { recursive: true }. The test verifies compilation, execution, nested-directory creation, output, and cleanup. A changelog entry documents the test.

Changes

mkdirSync options-object regression

Layer / File(s)	Summary
Recursive mkdirSync regression test crates/perry/tests/issue_8122_fs_mkdir_options_object.rs, changelog.d/8309-mkdir-options-object-regression.md	The test compiles and runs embedded Perry code, verifies nested-directory creation and PASS output, removes the temporary directory, and documents the regression coverage.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to 04237

This localized test-only change adds coverage for recursive mkdir options-object handling without changing production behavior; no actionable merge-blocking risk remains after normal checks and review.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the regression test for recursive fs.mkdirSync options-object decoding.
Description check	✅ Passed	The description covers the summary, changes, related issues, test plan, validation results, screenshots, and checklist.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/claude-mkdir-options-regression

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