fix: handle null/empty custom modes files to prevent 'Cannot read properties of null' error

[daniel-lxs]

Description

Fixes the issue where empty or null custom modes configuration files (custom_modes.yaml or .roomodes) cause a 'Cannot read properties of null (reading customModes)' error.

Problem

When the custom modes configuration file exists but is empty or contains null/undefined content, the YAML parser returns null, which causes a null pointer exception when trying to access the customModes property.

Solution

1. SimpleInstaller.ts:

   • Modified installMode and removeMode methods to ensure existingData is always a valid object after yaml.parse
   • Added explicit checks to convert null/undefined to an empty object with customModes array
   • Ensures customModes array is always initialized before use

2. CustomModesManager.ts:

   • Modified parseYamlSafely to return an empty object ({}) instead of null when yaml.parse returns null/undefined
   • This prevents null pointer exceptions in downstream code

Testing

• Added comprehensive test cases for handling empty files, null content, and missing customModes property
• Updated existing tests to match the correct behavior
• All tests pass successfully

Verification

The fix ensures that:

• Empty custom modes files are handled gracefully
• Files with null content (e.g., '---\n') are properly initialized
• Files without customModes property get the property added
• The file structure is always valid after any operation

This resolves the reported error and ensures robust handling of edge cases in custom modes configuration files.

---

Important

Fixes null pointer exceptions by ensuring customModes is always initialized in SimpleInstaller.ts and CustomModesManager.ts.

• Behavior:
  • Fixes null pointer exception in SimpleInstaller.ts and CustomModesManager.ts by ensuring customModes is always initialized.
  • parseYamlSafely in CustomModesManager.ts returns {} instead of null.
  • installMode and removeMode in SimpleInstaller.ts handle empty or null .roomodes files by initializing customModes.
• Testing:
  • Adds tests in SimpleInstaller.spec.ts for empty, null, and missing customModes cases.
  • Verifies correct behavior for invalid YAML and JSON scenarios.
• Misc:
  • Minor refactoring for error handling and initialization logic.

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[delve-auditor]

✅ No security or compliance issues detected. Reviewed everything up to bd517da.

Security Overview

• 🔎 Scanned files: 3 changed file(s)

Detected Code Changes

Change Type	Relevant files
Bug Fix	► CustomModesManager.ts     Handle null/undefined settings in updateModesInFile and loadModesFromFile ► SimpleInstaller.ts     Add null/undefined checks for YAML parsing and customModes property ► package.json     Remove overflow group assignments and prompts button ► SimpleInstaller.spec.ts     Add test cases for empty/null content handling

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