Rule request: `Get-Content x | ConvertFrom-Json` should suggest adding `-raw` for `Get-content`

[jessehouwing]

Summary of the new feature

When you call get-content file.json | convertfrom-json, funny things happen when file.json contains a comment at the top of the file.

Multiple places suggest that it's better to use get-content -raw for performance and predictability.

See:

• ConvertFrom-Json includes $null element on output if input starts with blank line PowerShell#12229
• https://stackoverflow.com/questions/71025659/set-property-value-on-object-loaded-from-json-containing-comments

Proposed technical implementation details (optional)

When get-content is piped to convertfrom-*, PSScriptAnalyzer should suggest adding -raw to get-content.

The same could apply to [xml] get-content file.xml.

What is the latest version of PSScriptAnalyzer at the point of writing

1.21

[SydneyhSmith]

Thanks for the suggestion @jessehouwing this would make a good custom rule, or this seems like the kind of thing that could be good for a feedback provider. Typically we don't add things into script analyzer that are code optimizers or work arounds. I will mark this as up for grabs if you want to try opening a PR for it.

[jessehouwing]

@SydneyhSmith which existing rule would be a good basis to use to build this from?

[bergmeister]

@jessehouwing See here for docs around custom rules: https://learn.microsoft.com/en-us/powershell/utility-modules/psscriptanalyzer/create-custom-rule?view=ps-modules
I kind of agree that we shouldn't add too many cmdlet specific rules but if this one is common, we could consider it, Here is a good, similar example: #1857