[Issue]: Add Pester tests for linting scripts (5 scripts)

[WilliamBerryiii]

Summary

Create unit tests for the core linting PowerShell scripts that perform markdown, link, and PSScriptAnalyzer validation.

Parent Issue: #190

Requirements

Create test files for each linting script:

• scripts/tests/linting/Invoke-LinkLanguageCheck.Tests.ps1
• scripts/tests/linting/Invoke-PSScriptAnalyzer.Tests.ps1
• scripts/tests/linting/Link-Lang-Check.Tests.ps1
• scripts/tests/linting/Markdown-Link-Check.Tests.ps1
• scripts/tests/linting/Validate-MarkdownFrontmatter.Tests.ps1

Implementation Details

Scripts Under Test

Script	Purpose	Key Functions
Invoke-LinkLanguageCheck.ps1	Link language validation	Parameter handling, output formatting
Invoke-PSScriptAnalyzer.ps1	PowerShell analysis	PSScriptAnalyzer invocation, result processing
Link-Lang-Check.ps1	Link validation	URL checking, result aggregation
Markdown-Link-Check.ps1	Markdown link checking	File discovery, link extraction
Validate-MarkdownFrontmatter.ps1	Frontmatter validation	YAML parsing, schema validation

Test Pattern

BeforeAll {
    # Use dot-sourcing pattern for scripts
    . $PSScriptRoot/../../linting/ScriptName.ps1
}

Describe 'Script-Name.ps1' {
    Context 'Parameter Validation' {
        It 'Should accept valid parameters' {
            # Test parameter binding
        }
        
        It 'Should reject invalid parameters' {
            { Invoke-Script -InvalidParam 'value' } | Should -Throw
        }
    }

    Context 'Core Functionality' {
        BeforeEach {
            # Mock external dependencies
            Mock Get-ChildItem { return @() }
            Mock Invoke-ExternalTool { return $null }
        }

        It 'Should process files correctly' {
            # Test main logic
        }
    }

    Context 'Output Formatting' {
        It 'Should produce valid JSON output' {
            $result = Invoke-Script -OutputFormat Json
            { $result | ConvertFrom-Json } | Should -Not -Throw
        }
    }
}

Shared Mocks Usage

BeforeAll {
    # Import shared test utilities
    . $PSScriptRoot/../TestHelpers/SharedMocks.ps1
    
    # Get mock file system
    $mockFiles = Get-MockMarkdownFiles
}

Acceptance Criteria

• Test file exists for each of the 5 linting scripts
• Parameter validation tests for each script
• Core logic tests with mocked dependencies
• Output format tests (JSON, console)
• Error handling tests
• All tests pass in CI environment

Dependencies

• [Issue]: Add Pester test infrastructure (config, directories, shared mocks) #193 (infrastructure) for test directory structure
• [Issue]: Integrate Pester tests into PR validation workflow #195 (LintingHelpers tests) for module mocking patterns

Estimated Effort

4-6 hours (5 scripts)

---

Additional Context

Target Scripts

• scripts/linting/Invoke-LinkLanguageCheck.ps1
• scripts/linting/Invoke-PSScriptAnalyzer.ps1
• scripts/linting/Link-Lang-Check.ps1
• scripts/linting/Markdown-Link-Check.ps1
• scripts/linting/Validate-MarkdownFrontmatter.ps1

Testing Priority

1. Validate-MarkdownFrontmatter.ps1 (complex schema logic)
2. Invoke-PSScriptAnalyzer.ps1 (integrates with external tool)
3. Remaining scripts

Related Issues

• Depends on: [Issue]: Add Pester test infrastructure (config, directories, shared mocks) #193 (infrastructure), [Issue]: Integrate Pester tests into PR validation workflow #195 (module tests)
• Parent: [Issue]: Add Pester unit testing framework for PowerShell scripts #190