[Issue]: Add Pester tests for LintingHelpers.psm1 module

[WilliamBerryiii]

Summary

Create comprehensive unit tests for LintingHelpers.psm1, the shared module containing helper functions used by multiple linting scripts.

Parent Issue: #190

Requirements

• Create scripts/tests/Modules/LintingHelpers.Tests.ps1
• Test all exported functions from LintingHelpers.psm1
• Use Pester 5.x syntax with Describe/Context/It blocks
• Mock filesystem and external dependencies
• Achieve minimum 80% code coverage for the module

Implementation Details

Target Functions

Based on research analysis, LintingHelpers.psm1 likely exports:

• Path resolution helpers
• Result formatting functions
• Common validation utilities
• JSON/output serialization helpers

Test Structure

BeforeAll {
    # Import module under test
    $ModulePath = Join-Path $PSScriptRoot '../../linting/Modules/LintingHelpers.psm1'
    Import-Module $ModulePath -Force
}

Describe 'LintingHelpers Module' {
    Context 'Module Structure' {
        It 'Should export expected functions' {
            $module = Get-Module LintingHelpers
            $module.ExportedFunctions.Keys | Should -Contain 'Get-ExpectedFunction'
        }
    }

    Context 'Function-Name' {
        It 'Should handle valid input' {
            # Arrange
            $input = 'test-value'
            
            # Act
            $result = Get-FunctionName -Input $input
            
            # Assert
            $result | Should -Be 'expected-output'
        }

        It 'Should handle edge cases' {
            # Test empty input, null, special characters, etc.
        }
    }
}

AfterAll {
    Remove-Module LintingHelpers -ErrorAction SilentlyContinue
}

Mocking Patterns

BeforeEach {
    # Mock filesystem operations
    Mock Test-Path { return $true }
    Mock Get-Content { return '{"key": "value"}' }
    
    # Mock external commands if needed
    Mock Invoke-ExternalTool { return @{ Success = $true } }
}

Acceptance Criteria

• Test file exists at scripts/tests/Modules/LintingHelpers.Tests.ps1
• All exported functions have corresponding test coverage
• Tests use proper Pester 5.x syntax
• Mocks isolate tests from filesystem/external dependencies
• Tests pass in CI environment (ubuntu-latest)
• Code coverage >= 80% for module

Dependencies

• [Issue]: Add Pester test infrastructure (config, directories, shared mocks) #193 (infrastructure) provides test directory structure and shared mocks

Estimated Effort

2-3 hours

---

Additional Context

Target File

• scripts/linting/Modules/LintingHelpers.psm1 - Module under test

Why Module Tests First

Testing the shared module first:

1. Establishes mocking patterns for dependent scripts
2. Validates test infrastructure with simpler target
3. Provides reusable test helpers for script tests

Related Issues

• Depends on: [Issue]: Add Pester test infrastructure (config, directories, shared mocks) #193 (infrastructure)
• Blocks: Linting scripts tests, frontmatter tests
• Parent: [Issue]: Add Pester unit testing framework for PowerShell scripts #190