Fix PowerShell class to support deriving from an abstract class with abstract properties #21331

daxian-dbw · 2024-03-12T05:43:20Z

PR Summary

Fix PowerShell class to support deriving from an abstract class with abstract properties.
The fix is to detect that we are deriving from an abstract base type, and the property is an implementation of an abstract property from that base type.

PR Context

The following PowerShell class stops working in PowerShell v7.4.1, because .NET 8 enforces stricter validation on the dynamically emitted IL code. Previously, for a property that is supposed to be the implementation of an abstract property in base type, we don't set the Reflection.MethodAttributes.Virtual attribute when creating the property. That actually makes the created property have nothing to do with the abstract property in base type. Prior to .NET 8, the IL emitting library doesn't detect this error even though the abstract property is not implemented. However, starting from .NET 8, it detects the issue and throw exception in this case.

Running the following PowerShell class will result in an error in v7.4.1

class nxFileSystemInfo : System.IO.FileSystemInfo
{
    [string] $Name
    [bool] $Exists

    [void] Delete()
    {
    }
}

ParserError:
Line |
   1 |  class nxFileSystemInfo : System.IO.FileSystemInfo
     |  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     | Error during creation of type "nxFileSystemInfo". Error message: Method 'get_Name' in type 'nxFileSystemInfo' from assembly 'PowerShell Class
     | Assembly, Version=1.0.0.2, Culture=neutral, PublicKeyToken=null' does not have an implementation.

PR Checklist

…abstract properties

pull-request-quantifier-deprecated · 2024-03-12T05:43:25Z

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jborean93 · 2024-03-12T10:16:39Z

It would be great if you could look at #21062 and #21061 which is still pending a review and tried to fix somewhat related problems to this.

daxian-dbw · 2024-03-12T16:58:24Z

@jborean93 Will do a review later today or tomorrow. Thanks for the reminder!

JamesWTruher · 2024-03-12T18:40:16Z

test/powershell/Language/Classes/scripting.Classes.inheritance.tests.ps1

@@ -628,3 +628,33 @@ class Derived : Base
        $sb.Invoke() | Should -Be 200
    }
 }
+
+Describe 'Base type has abstract properties' -Tags "CI" {


do we have validation which ensures that an error is produced if the abstract property is not defined? is it needed?

Good point. I will add one.

A test for the error case was added.

SeeminglyScience · 2024-03-12T18:50:04Z

src/System.Management.Automation/engine/parser/PSType.cs

+
+                    if (_typeBuilder.BaseType.IsAbstract)
+                    {
+                        foreach (var property in _typeBuilder.BaseType.GetProperties())


I believe this will need to include BindingFlags.NonPublic as protected members should still be found right? Likewise GetAccessors below likely needs nonPublic: true.

Then a check like

accessor.IsFamilyOrAssembly || accessor.IsFamily || assessor.IsPublic

Interfaces may also actually need that check too since C# 8 added the ability to mark members as protected. Though that wouldn't be fixing a regression so likely fine to leave out of this PR.

But we don't create properties or methods with the "protected" (family) modifier, and we don't have a keyword in PowerShell language to declare a property as protected, we only create public (by default or with the hidden keyword) or static (static keyword) members. So, even if we check for protected abstract properties here, the public property we are going to create later won't be considered as an implementation of the protected property.

When a base type (MyBase) has a protected abstract property Name, the class definition class MySub : MyBase { [string]$Name } will fail on 7.2 and 7.3 as well today (see the screenshots below). So, I think we just don't support deriving from a class that has protected abstract properties/methods.

7.2.18

7.3.11

Ah alright if it failed before then good enough for me!

SeeminglyScience

LGTM!

pull-request-quantifier-deprecated · 2024-03-13T21:24:58Z

This PR has 40 quantified lines of changes. In general, a change size of upto 200 lines is ideal for the best PR experience!

Quantification details

Label      : Extra Small
Size       : +35 -5
Percentile : 16%

Total files changed: 2

Change summary by file extension:
.cs : +9 -5
.ps1 : +26 -0

Change counts above are quantified counts, based on the PullRequestQuantifier customizations.

Why proper sizing of changes matters

Optimal pull request sizes drive a better predictable PR flow as they strike a
balance between between PR complexity and PR review overhead. PRs within the
optimal size (typical small, or medium sized PRs) mean:

Fast and predictable releases to production:
- Optimal size changes are more likely to be reviewed faster with fewer
  iterations.
- Similarity in low PR complexity drives similar review times.
Review quality is likely higher as complexity is lower:
- Bugs are more likely to be detected.
- Code inconsistencies are more likely to be detected.
Knowledge sharing is improved within the participants:
- Small portions can be assimilated better.
Better engineering practices are exercised:
- Solving big problems by dividing them in well contained, smaller problems.
- Exercising separation of concerns within the code changes.

What can I do to optimize my changes

Use the PullRequestQuantifier to quantify your PR accurately
- Create a context profile for your repo using the context generator
- Exclude files that are not necessary to be reviewed or do not increase the review complexity. Example: Autogenerated code, docs, project IDE setting files, binaries, etc. Check out the Excluded section from your prquantifier.yaml context profile.
- Understand your typical change complexity, drive towards the desired complexity by adjusting the label mapping in your prquantifier.yaml context profile.
- Only use the labels that matter to you, see context specification to customize your prquantifier.yaml context profile.
Change your engineering behaviors
- For PRs that fall outside of the desired spectrum, review the details and check if:
  - Your PR could be split in smaller, self-contained PRs instead
  - Your PR only solves one particular issue. (For example, don't refactor and code new features in the same PR).

How to interpret the change counts in git diff output

One line was added: +1 -0
One line was deleted: +0 -1
One line was modified: +1 -1 (git diff doesn't know about modified, it will
interpret that line like one addition plus one deletion)
Change percentiles: Change characteristics (addition, deletion, modification)
of this PR in relation to all other PRs within the repository.

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microsoft-github-policy-service · 2024-03-13T21:45:09Z

📣 Hey @daxian-dbw, how did we do? We would love to hear your feedback with the link below! 🗣️

🔗 https://aka.ms/PSRepoFeedback

Microsoft Forms

…abstract properties (PowerShell#21331)

…tract class with abstract properties (#21331) (#21422)

Fix PowerShell class to support deriving from an abstract class with …

ebb9cfc

…abstract properties

pull-request-quantifier-deprecated bot added the Extra Small label Mar 12, 2024

daxian-dbw requested review from SteveL-MSFT and SeeminglyScience March 12, 2024 18:27

daxian-dbw self-assigned this Mar 12, 2024

daxian-dbw added CL-Engine Indicates that a PR should be marked as an engine change in the Change Log BackPort-7.4.x-Consider labels Mar 12, 2024

JamesWTruher reviewed Mar 12, 2024

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SeeminglyScience reviewed Mar 12, 2024

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SeeminglyScience approved these changes Mar 13, 2024

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SteveL-MSFT approved these changes Mar 13, 2024

View reviewed changes

Add a test for the error case

d7e4fc1

daxian-dbw mentioned this pull request Mar 13, 2024

Implement the abstract property 'Exists' from the base type 'FileSystemInfo` Azure/nxtools#52

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8 tasks

daxian-dbw merged commit 4e357f1 into PowerShell:master Mar 13, 2024
38 checks passed

daxian-dbw deleted the psclass branch March 13, 2024 21:45

daxian-dbw added BackPort-7.4.x-Approved and removed BackPort-7.4.x-Consider labels Mar 25, 2024

SeeminglyScience pushed a commit to SeeminglyScience/PowerShell that referenced this pull request Apr 4, 2024

Fix PowerShell class to support deriving from an abstract class with …

5ea8d1c

…abstract properties (PowerShell#21331)

SeeminglyScience mentioned this pull request Apr 4, 2024

[release/v7.4.2] Fix PowerShell class to support deriving from an abstract class with abstract properties #21422

Merged

daxian-dbw pushed a commit that referenced this pull request Apr 4, 2024

[release/v7.4.2] Fix PowerShell class to support deriving from an abs…

0e4b9d7

…tract class with abstract properties (#21331) (#21422)

SeeminglyScience added BackPort-7.4.x-Done and removed BackPort-7.4.x-Approved labels Apr 5, 2024

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Fix PowerShell class to support deriving from an abstract class with abstract properties #21331

Fix PowerShell class to support deriving from an abstract class with abstract properties #21331

daxian-dbw commented Mar 12, 2024 •

edited

pull-request-quantifier-deprecated bot commented Mar 12, 2024

What can I do to optimize my changes

How to interpret the change counts in git diff output

jborean93 commented Mar 12, 2024 •

edited

daxian-dbw commented Mar 12, 2024

JamesWTruher Mar 12, 2024 •

edited

daxian-dbw Mar 12, 2024

daxian-dbw Mar 13, 2024

SeeminglyScience Mar 12, 2024

daxian-dbw Mar 13, 2024 •

edited

SeeminglyScience Mar 13, 2024

SeeminglyScience left a comment

pull-request-quantifier-deprecated bot commented Mar 13, 2024

What can I do to optimize my changes

How to interpret the change counts in git diff output

microsoft-github-policy-service bot commented Mar 13, 2024 •

edited by unfurl-links bot

Fix PowerShell class to support deriving from an abstract class with abstract properties #21331

Fix PowerShell class to support deriving from an abstract class with abstract properties #21331

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daxian-dbw commented Mar 12, 2024 • edited

PR Summary

PR Context

PR Checklist

pull-request-quantifier-deprecated bot commented Mar 12, 2024

What can I do to optimize my changes

How to interpret the change counts in git diff output

jborean93 commented Mar 12, 2024 • edited

daxian-dbw commented Mar 12, 2024

JamesWTruher Mar 12, 2024 • edited

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pull-request-quantifier-deprecated bot commented Mar 13, 2024

What can I do to optimize my changes

How to interpret the change counts in git diff output

microsoft-github-policy-service bot commented Mar 13, 2024 • edited by unfurl-links bot

daxian-dbw commented Mar 12, 2024 •

edited

jborean93 commented Mar 12, 2024 •

edited

JamesWTruher Mar 12, 2024 •

edited

daxian-dbw Mar 13, 2024 •

edited

microsoft-github-policy-service bot commented Mar 13, 2024 •

edited by unfurl-links bot