fix: align description fallback pattern across commands, subagents and rules

[saitota]

Summary

• Remove description ?? "" and description || "" fallback patterns in commands, subagents and rules to propagate undefined instead of empty string
• Make description field optional (z.optional(z.string())) across all command/subagent schemas for consistency with RulesyncRuleFrontmatterSchema
• Improve cursor-rule.ts truthiness check to use explicit !== undefined && !== null && !== "" guard instead of falsy check
• Add deepRemoveNullishObject edge case test for nested objects with all-null values

Closes #1078

Note

This PR addresses all occurrences of the description ?? "" / description || "" pattern found across the codebase, not just the two files mentioned in the issue #1078 .

References

• fix: prevent empty descriptions from being serialized as YAML null in frontmatter #1070
• Cursor rule generation outputs empty description: when source has no description, breaking re-import #1068

Test plan

• pnpm check
• pnpm test (4098 passed)

[dyoshikawa-claw]

/opencode review

[dyoshikawa-claw]

/opencode review

[github-actions]

PR Review Summary (PR addressing issue #1078)

Code Review Findings

1. Overall Assessment: ✅ Good Quality PR - The PR successfully aligns the description field handling across commands, subagents, and rules. All CI checks pass (4098 tests).

2. Inconsistency in kiro-subagent.ts ⚠️ Minor Issue - description: description ?? undefined is unnecessarily verbose. Should be just description: description for consistency.

3. Deletion Placeholder Values - Acceptable ✅ - Empty strings in simulated-command.ts and simulated-subagent.ts are acceptable since validate: false bypasses schema validation for deletion scenarios.

4. cursor-rule.ts Truthiness Check - Good Improvement ✅ - The explicit !== undefined && !== null && !== "" guard is clearer than the previous falsy check.

5. Test Coverage - Comprehensive ✅ - All affected tests updated, new edge case test added for deepRemoveNullishObject.

6. Schema Consistency - Complete ✅ - All command/subagent schemas now use z.optional(z.string()) matching RulesyncRuleFrontmatterSchema.

7. No Missed Files ✅ - No remaining description ?? "" or description || "" patterns exist.

Security Review Findings

8. No New Security Vulnerabilities ✅ - Zod schema validation ensures description must be a string when present, maintaining type safety.

9. Safe Fallback Pattern Removal ✅ - undefined values properly handled by deepRemoveNullishObject() before YAML serialization.

10. Pre-existing YAML Concern in cursor-rule.ts ⚠️ (Not new to this PR) - Manual YAML building in stringifyCursorFrontmatter() lacks proper escaping. Low severity since it's a local CLI tool.

11. No Command Injection Risk ✅ - Description values only used for file output and internal data structures.

12. Input Validation Adequate ✅ - z.optional(z.string()) properly validates input.

Recommendation

Ready to merge with one minor optional fix: remove redundant ?? undefined in kiro-subagent.ts for consistency.

github run