PowerShell / PowerShell/PSScriptAnalyzer
Rule Idea: Pipeline Type Checking against Output
Nobody has claimed this yet.
- Dominant language
- C#
- Stars
- 2.2k
- Forks
- 414
- Avg merge
- 13h 1m
- Merged PRs (30d)
- 2
Description
This is just a spitball idea to contribute feedback if it is maybe feasible, I might consider attempting a PR
Problem
Often when writing a pipeline you may pipe an incompatible type, and you won't find out until runtime.
Proposed solution
If the output type of a function can be explicitly determined by:
- Use the .OUTPUT comment based help section to define the output type of a function
- Take all explicit return keywords that explicitly cast to a type e.g.
return [MyType]@{}or can be simply derived from a typed variable e.g.$f = [MyType]::new();return $f
And the function being called either to or from meets the following criteria:
- Has strictly typed non-primitive parameter or ValueFromPipeline
Then we should be able to safely issue a warning or error stating something like "MyFunction expected [MyType] but is receiving [WrongType] via the pipeline" as a static analysis.
#Issues
- Easily castable types like string we have to exclude, they will basically always match
- Probably should support/detect explicit casts or interfaces
Prior Art
How JSDoc can be used to test for type safety in normally-untyped javascript.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reviewing the proposed output-type sources, pipeline parameter checks, casting exceptions, and the JSDoc prior art described in the issue. Define the analyzer entry point and scope before implementation; done means a decided approach can detect incompatible pipeline types while excluding safely castable values and handling explicit casts or interfaces.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- powershell
- Domain
- tooling
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100