https://github.com/calvindd2f/pslint
PowerShell Performance Linter
https://github.com/calvindd2f/pslint
Last synced: 10 months ago
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PowerShell Performance Linter
- Host: GitHub
- URL: https://github.com/calvindd2f/pslint
- Owner: Calvindd2f
- License: mit
- Created: 2024-10-03T23:20:33.000Z (over 1 year ago)
- Default Branch: master
- Last Pushed: 2025-06-21T00:57:21.000Z (12 months ago)
- Last Synced: 2025-06-21T01:36:21.773Z (12 months ago)
- Language: PowerShell
- Size: 139 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.MD
- License: LICENSE.TXT
- Support: .github/Support_Query.md
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PSlint
A performance-focused linter for PowerShell scripts and modules.
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Table of Contents
-
About The Project
-
Getting Started
- Usage
- Custom Rules
- Rule Reference
- Roadmap
- Contributing
- License
- Contact
- Acknowledgments
## About The Project
`pslint` is a static analysis tool for PowerShell that focuses on identifying performance bottlenecks in scripts and modules. Unlike linters that enforce idiomatic style, `pslint` prioritizes optimizations that can significantly reduce resource consumption and execution time. This makes it particularly useful for scenarios like:
- Optimizing long-running scripts.
- Reducing execution time for Azure Functions and Runbooks.
- Improving the performance of resource-intensive modules.
### Features
`pslint` analyzes your code using the Abstract Syntax Tree (AST) to detect a variety of performance issues, including:
- **Output Suppression**: Detects inefficient ways of suppressing output like `| Out-Null` or `> $null` and suggests faster alternatives like `[void]`.
- **Array Addition**: Identifies the use of the `+=` operator on arrays, which can be slow, and recommends using `System.Collections.ArrayList` or `System.Collections.Generic.List[T]`.
- **String Concatenation**: Flags inefficient string concatenation and suggests using methods like the `-f` format operator or `StringBuilder`.
- **Large File Processing**: Warns against reading large files into memory at once with `Get-Content` and suggests using streaming methods.
- **`Write-Host` Usage**: Recommends using `Write-Output` or other appropriate cmdlets over `Write-Host` for better stream control.
- **And more...**: Including checks for large collection lookups, inefficient loops, and dynamic object creation with `Add-Member`.
## Custom Rules
## Getting Started
### Prerequisites
No prerequisites required for using this module. It is compatible with both Windows PowerShell and PowerShell Core.
### Installation
Install `pslint` from the PowerShell Gallery:
```pwsh
Install-Module -Name pslint -Repository PSGallery -Scope CurrentUser
Import-Module pslint
```
## Usage
You can analyze a script file directly or analyze a `ScriptBlock` object.
**Analyze a file:**
```powershell
pslint -Path 'C:\path\to\your-script.ps1'
```
**Analyze a ScriptBlock:**
```powershell
$scriptBlock = {
$myArray = @()
1..1000 | ForEach-Object { $myArray += $_ }
$myArray | Out-Null
}
pslint -ScriptBlock $scriptBlock
```
**Example Output:**
```pwsh
=== PowerShell Performance Analysis Report ===
Script: C:\Users\c\win10_portscan.ps1
Time: 2024-10-08 03:32:45
Summary:
Total Issues Found: 19
== ArrayAddition (2 issues) ==
Line 81:
Code:
$IPList.Add($CurrIP)
Suggestion: Consider using ArrayList or Generic List for better performance
Line 135:
Code:
$hosts += [PSCustomObject]@{
value = "$($($IP.IP).Trim())";
port = "$($Port.Trim())";
}
Suggestion: Consider using ArrayList or Generic List for better performance
== LargeCollectionLookup (1 issues) ==
Line 135:
Code:
@{
value = "$($($IP.IP).Trim())";
port = "$($Port.Trim())";
}
Suggestion: Consider using Dictionary for large collections
== OutputSuppression (10 issues) ==
Line 8:
Code: $null|out-null
Suggestion: Consider using [void] for better performance
Line 9:
Code: $null|out-null
Suggestion: Consider using [void] for better performance
== WriteHostUsage (6 issues) ==
Line 97:
Code:
Write-Host "WARNING: Scan took longer than 15 seconds, ARP entries may have been flushed. Recommend lowering DelayMS parameter"
Suggestion: Consider using [Console]::writeline() , Write-Output or Write-Information.
Line 119:
Code:
Write-host "Started scanning at $($start_time)"
Suggestion: Consider using [Console]::writeline() , Write-Output or Write-Information.
Line 172:
Code:
Write-Host "Hosts Found: $($hosts.Count)"
Suggestion: Consider using [Console]::writeline() , Write-Output or Write-Information.
Line 175:
Code:
write-host $(ConvertTo-Json $hosts -Depth 5)
Suggestion: Consider using [Console]::writeline() , Write-Output or Write-Information.
Line 183:
Code:
Write-Host "Total Time: $($total.ToString())"
Suggestion: Consider using [Console]::writeline() , Write-Output or Write-Information.
Line 184:
Code:
Write-Host "Finished scanning at $($end_time)"
Suggestion: Consider using [Console]::writeline() , Write-Output or Write-Information.
```
## Custom Rules
`pslint` can also evaluate rules provided in your own modules. Export your rule functions and specify their paths in a ScriptAnalyzer settings file:
```powershell
$settings = @{
CustomRulePath = '.\\MyRules'
IncludeRules = 'Measure-*'
}
Invoke-ScriptAnalyzer -Path .\script.ps1 -Settings $settings
```
In Visual Studio Code set "powershell.scriptAnalysis.settingsPath" to the settings file so custom rules run automatically.
## Rule Reference
For details on the built-in rules and examples of recommended fixes see [docs/rules_overview.md](docs/rules_overview.md).
## Roadmap
- [x] Reliable detection via Abstract Syntax Tree (AST) parsing.
- [x] Formatted and actionable output.
- [x] Published to PowerShell Gallery.
- [x] Improve accuracy through extensive real-world testing.
- [x] Implement corrective actions (auto-fixing).
- [x] Enhance rule documentation and provide clear examples.
See the [open issues](https://github.com/calvindd2f/pslint/issues) for a full list of proposed features (and known issues).
## Contributing
Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are **greatly appreciated**.
If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement".
Don't forget to give the project a star! Thanks again!
1. Fork the Project
2. Create your Feature Branch (`git checkout -b feature/AmazingFeature`)
3. Commit your Changes (`git commit -m 'Add some AmazingFeature'`)
4. Push to the Branch (`git push origin feature/AmazingFeature`)
5. Open a Pull Request
### Top contributors
## License
Distributed under the MIT License. See `LICENSE.txt` for more information.
## Contact
Project Maintainer: [@Calvindd2f](https://twitter.com/Dreadytofat) -
Project Link: [https://github.com/calvindd2f/pslint](https://github.com/calvindd2f/pslint)
## Acknowledgments
- [Best README Template](https://github.com/othneildrew/Best-README-Template)
### Built With
- [PowerShell](https://learn.microsoft.com/en-us/powershell/)
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[stars-url]: https://github.com/calvindd2f/pslint/stargazers
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[issues-url]: https://github.com/calvindd2f/pslint/issues
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[license-url]: https://github.com/calvindd2f/pslint/blob/master/LICENSE.txt
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```
```