powershell-code-review

PowerShell Code Review

Conduct production-readiness audits of PowerShell scripts and modules for Fortune 100 enterprise environments. Apply Elon Musk's 5-Step Design Process to eliminate waste, simplify logic, and harden code — in that order.

Review Philosophy

Apply the 5 steps in order. Do not skip ahead.

Step	Principle	Action
1	Make requirements less dumb	Challenge every requirement. Who signed off on this? Why does it exist?
2	Delete	Most critical step. Remove everything that cannot justify its existence.
3	Simplify / Optimize	Only after deletion. Never optimize what should not exist.
4	Accelerate cycle time	Does this code enable faster iteration or create bottlenecks?
5	Automate	Last step only. Never automate what should be deleted.

Default to deletion. Prove code must exist — don't assume it should.

See review-philosophy.md for the full elimination target list and challenge checklist.

Workflow

1. Receive Code

Accept PowerShell code as:

• Inline paste
• File path reference
• GitHub URL

2. Apply the 5-Step Process

Work through each step before moving to the next:

Step 1 — Question requirements

• Who defined this requirement?
• What breaks if this code does not exist?
• Is this solving a real problem or a hypothetical one?

Step 2 — Delete Ruthlessly eliminate (see full list in review-philosophy.md):

• Parameters that are "nice to have"
• Functions wrapping single cmdlets without adding value
• Defensive checks masking design flaws
• Comments explaining bad code (rewrite instead)
• Begin/End blocks where Process alone suffices
• Helper functions used in only one place
• Code that exists "just in case"

Step 3 — Simplify After deleting, simplify what remains:

• Replace loops with pipeline operations where appropriate
• Replace string building with here-strings
• Replace custom formatting with structured objects or Select-Object calculated properties; leave final formatting to the caller
• Remove abstraction layers with no real reuse

Step 4 — Accelerate

• Does this pattern slow down future changes?
• Are there N+1 API call patterns?
• Is object materialization blocking streaming?

Step 5 — Automate

• Is this something a build/CI pipeline should handle instead?
• Are there manual steps that should be automated?

3. Categorize Issues

Review across all categories:

Category	Focus
Correctness & Logic	Bugs, flawed assumptions, data flow errors, Graph/API call accuracy
Security	Credentials, tokens, input validation, injection risks, least privilege
Performance	Redundant calls, N+1 patterns, unnecessary materialization
PowerShell Best Practices	Naming, [CmdletBinding()], pipeline design, error handling
Cross-Platform	PowerShell Core compatibility, OS-specific isolation
Error Handling & Logging	Terminating vs non-terminating, structured errors, no generic catches
Maintainability	SRP, DRY/KISS/YAGNI, readability without comments, guard clauses

See review-philosophy.md for per-category checklists.

4. Produce the Report

Output a markdown report using the structure in report-template.md:

## Executive Summary
## Critical Issues
## Recommended Deletions
## Recommended Enhancements
## Optional Improvements
## Risk Assessment
## Appendix: Deletion Summary

Save the report as <ScriptName>-review.md unless the user specifies a path.

PowerShell Best Practices Quick Reference

Naming

• Approved verbs only (Get-Verb)
• Singular nouns, PascalCase
• No aliases in scripts — always use full cmdlet and parameter names

Functions

function Verb-Noun {
    [CmdletBinding(SupportsShouldProcess)]
    param(
        [Parameter(Mandatory, ValueFromPipeline)]
        [ValidateNotNullOrEmpty()]
        [string]$Name
    )
    process {
        if ($PSCmdlet.ShouldProcess($Name, 'Action')) {
            # implementation
        }
    }
}

Error Handling

# Prefer typed exceptions over generic catch
try {
    $result = Get-Item -Path $Path -ErrorAction Stop
}
catch [System.IO.FileNotFoundException] {
    $PSCmdlet.WriteError(
        [System.Management.Automation.ErrorRecord]::new(
            $_.Exception,
            'FileNotFound',
            [System.Management.Automation.ErrorCategory]::ObjectNotFound,
            $Path
        )
    )
    return
}
# Never swallow exceptions silently

Output

• Objects, not formatted text — consumers decide how to display
• PSCustomObject for structured data
• PassThru pattern for action cmdlets
• Write-Output for data; Write-Verbose/Write-Warning for status

Destructive Operations

# Always ShouldProcess for operations that change state
[CmdletBinding(SupportsShouldProcess, ConfirmImpact = 'High')]
param()
process {
    if ($PSCmdlet.ShouldProcess($Target, 'Remove')) {
        Remove-Item -Path $Target -Force
    }
}

Review Principles

• No politeness tax — Direct criticism accelerates improvement
• Code over comments — Self-documenting code beats explained bad code
• Demand evidence — Claims require proof (benchmarks, failure scenarios)
• Question best practices — Do they improve this code or just look good?
• The best code is no code — Every line is a liability until proven otherwise

References

• review-philosophy.md — Full elimination targets, per-category checklists, challenge questions
• report-template.md — Markdown report output template with section guidance