Powershell Scripting Practices

PowerShell Scripting Practices

Application skill for PoshCode PowerShellPracticeAndStyle (archived awesome-guidelines capsules). For bash glue, use shell-scripting-practices. For.NET library API naming, use dotnet-coding-practices.

Core Principle

PowerShell quality is advanced functions emitting pipeline objects with explicit, trappable errors, not Write-Host scripts with alias cmdlets.

When to Use / NOT

• .ps1 controllers, .psm1 modules, advanced functions, Azure/automation scripts.
• Reviewing Verb-Noun tools, error handling, credential handling, formatting rules.

NOT when:

• Bash/sh only environments, shell-scripting-practices.
• C#/VB syntax, language practice skills.
• Generated Pester stub files, validate generators.

Workflow

1. Formatting, OTBS, blocks, splatting (powershell-style-formatting-layout.md).
2. Naming, Verb-Noun, full cmdlets, paths (powershell-style-naming-commands.md).
3. Functions/tools, process output, raw objects (powershell-style-functions-tools.md).
4. Errors/security, Stop, try/catch, PSCredential (powershell-style-errors-security.md).
5. Verify, PSScriptAnalyzer + Invoke-Formatter on changed scripts.

Red Flags

• Missing [CmdletBinding()]
• Mixed/inconsistent brace style
• Backtick continuation where splatting/parens work
• Alias cmdlets or positional-only calls in shared code
• Relative paths/~ without $PSScriptRoot discipline
• return in advanced function for pipeline emission
• Output from begin/end instead of process for pipeline input
• Write-Host for data output (non-Show/Format)
• Mixed pipeline object types without separation
• Custom ping/file helpers ignoring built-in cmdlets
• Plain-text password parameters
• Get-Credential inside reusable function
• $continue flag error handling
• $? used as error detail probe
• Null-test instead of exception on failing cmdlet
• Exported function missing comment-based help
• Trailing whitespace or semicolon terminators
• PSScriptAnalyzer findings ignored without rationale

Verification

• Invoke-ScriptAnalyzer (PSScriptAnalyzer) on changed .ps1/.psm1
• Invoke-Formatter / project formatter check when configured
• Pipeline test for ValueFromPipeline functions
• Failure-path test with -ErrorAction Stop behavior
• Capsule checklist on tool vs controller split

References

• awesome-guidelines/references/powershell-style-learning-note.md
• awesome-guidelines/references/powershell-style-formatting-layout.md
• awesome-guidelines/references/powershell-style-naming-commands.md
• awesome-guidelines/references/powershell-style-functions-tools.md
• awesome-guidelines/references/powershell-style-errors-security.md