fix(node:test): preserve mock function metadata

[proggeramlug]

Summary

• preserve the original function name on mock.fn(original) wrappers
• preserve the original function arity as the mock wrapper length
• expose Node-compatible configurable name and length descriptors
• keep all mock construction values rooted across metadata allocations

Refs #6767

Verification

• cargo check -p perry-runtime
• cargo test -p perry-runtime mock_function_preserves_original_name_length_and_descriptors -- --nocapture
• ./run_parity_tests.sh --suite node-suite --module test --filter node-suite/test/mock-fn/name-length (100% parity)

Summary by CodeRabbit

• Bug Fixes

  • Mock functions now preserve the original function’s name and expected argument count.
  • Mocked name and length properties now retain standard non-writable, non-enumerable, and configurable behavior.

• Tests

  • Added coverage confirming metadata and property descriptor preservation for mocked functions.

• Documentation

  • Added a changelog entry describing the improved mock function metadata behavior.

[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: b07984fe-9208-4499-b4a4-afce6130e08c

📥 Commits

Reviewing files that changed from the base of the PR and between c86835f and 0f8cff8.

📒 Files selected for processing (3)

• changelog.d/7099-node-test-mock-name-length.md
• crates/perry-runtime/src/node_submodules/test.rs
• crates/perry-runtime/src/node_submodules/test_metadata_unit_tests.rs

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📝 Walkthrough

Walkthrough

node:test mock functions now preserve callable names, argument lengths, and property descriptors. Mock creation also roots relevant values through RuntimeHandleScope, with unit coverage and a changelog entry.

Changes

Mock Function Metadata

Layer / File(s)	Summary
Metadata extraction and rooted mock creation crates/perry-runtime/src/node_submodules/test.rs	Mock creation derives callable names and lengths, roots relevant values, and applies metadata to generated closures.
Metadata descriptor validation crates/perry-runtime/src/node_submodules/test.rs, crates/perry-runtime/src/node_submodules/test_metadata_unit_tests.rs	Unit tests verify preserved name, arity, and non-writable, non-enumerable, configurable name and length properties.

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

Possibly related PRs

• PerryTS/perry#7096: Both modify shared node:test mock/export handling in test.rs.
• PerryTS/perry#7097: Both modify mock-function creation and rooted values in test.rs.
• PerryTS/perry#7098: Both modify mock internals and add tests in node_submodules/test.rs.

Suggested labels: bug

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: preserving metadata for node:test mock functions.
Description check	✅ Passed	The description explains the changes, references issue #6767, and lists concrete verification commands, though it omits several template headings and checklist items.
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 unit tests (beta)

• Create PR with unit tests

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