Show optional parameters as such when dislplaying method definition and overloads

[eugenesmlv]

PR Summary

These changes provide more informative method definition for methods with the optional parameters.

• Primitive value types and strings.

static void Bar(int optParam = -1)
static void Bar(string optParam = "default string")

• Reference types.

static void Bar(string optParam = null)

• Enums.

static void Bar(System.UriKind optParam = System.UriKind.Relative)

• Structs and generic method parameters.

static void Bar(datetime optParam = default)
static void GenericBar[T](T optParam = default)

PR Context

Fix #13728

The changes don't cover a case with an OptionalAttribute. Calling such a method without optional arguments throws an exception.

Add-Type -NameSpace demo -Name Foo -MemberDefinition @"
public static void Bar([System.Runtime.InteropServices.Optional]int optParam) { }
"@

[demo.Foo]::Bar()
#OperationStopped: Expression of type 'System.Reflection.Missing' cannot be used for parameter of type 'System.Int32' of method 'Void Bar(Int32)' (Parameter 'arg0')

I could investigate it if you show me where to start.

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• User-facing changes
  • Not Applicable
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  • Documentation needed
    • Issue filed:
• Testing - New and feature
  • N/A or can only be tested interactively
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  • Make sure you've added a new test if existing tests do not effectively test the code changed
• Tooling
  • I have considered the user experience from a tooling perspective and don't believe tooling will be impacted.
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    • Impact on PowerShell Editor Services which is used in the PowerShell extension for VSCode (which runs in a different PS Host).
    • Impact on Completions (both in the console and in editors) - one of PowerShell's most powerful features.
    • Impact on PSScriptAnalyzer (which provides linting & formatting in the editor extensions).
    • Impact on EditorSyntax (which provides syntax highlighting with in VSCode, GitHub, and many other editors).

[eugenesmlv]

@iSazonov it seems like CompletionCompleters also uses a method definition for the tooltip. Is it possible to test that case somehow?

PowerShell/src/System.Management.Automation/engine/CommandCompletion/CompletionCompleters.cs

Lines 5312 to 5318 in 67bdf72

	var methodCacheEntry = member as DotNetAdapter.MethodCacheEntry;
	if (methodCacheEntry != null)
	{
	memberName = methodCacheEntry[0].method.Name;
	isMethod = true;
	getToolTip = () => string.Join("\n", methodCacheEntry.methodInformationStructures.Select(m => m.methodDefinition));
	}

[iSazonov]

it seems like CompletionCompleters also uses a method definition for the tooltip. Is it possible to test that case somehow?

You can use TabCompletion2 (see our tests how it is used).

[eugenesmlv]

You can use TabCompletion2 (see our tests how it is used).

I couldn't find TabCompletion2 anywhere. Do you mean TabExpansion2? Anyway, as far as I understand, tab completion completes just method name and there are already tests for that.

Do you mean "method signature"?

Rather, "method signature with parameters of various types such as parameters passed by reference, generic and optional parameters", but it seems to me, we could combine tests for the overloaded definition and different method signature into one context.

I also want to suggest to mark parameters passed by reference with [in] and [out] keywords in addition to the [ref]. Can I implement that in this PR?

[SeeminglyScience]

You can use TabCompletion2 (see our tests how it is used).

I couldn't find TabCompletion2 anywhere. Do you mean TabExpansion2? Anyway, as far as I understand, tab completion completes just method name and there are already tests for that.

Tab expansion results include a tooltip, which is only shown in editors and some PSReadLine key handlers (but not the Tab one). You can see it here:

(TabExpansion2 -inputScript ($s = '$Host.PushRunspace') -cursorColumn $s.Length).CompletionMatches

returns

CompletionText ListItemText ResultType ToolTip
-------------- ------------ ---------- -------
PushRunspace(  PushRunspace     Method void PushRunspace(runspace runspace)…

I also want to suggest to mark parameters passed by reference with [in] and [out] keywords in addition to the [ref]. Can I implement that in this PR?

Maybe best to open an issue to discuss that one. Part of the problem there is that [in] and [out] aren't really a thing in PowerShell, so the way to pass it will still be [ref].

[iSazonov]

I couldn't find TabCompletion2 anywhere. Do you mean TabExpansion2?

Yes, sorry.

[eugenesmlv]

@iSazonov @SeeminglyScience thanks for helping me! I've added tests for the TabExpansion2 tooltip.

[ghost]

This pull request has been automatically marked as Review Needed because it has been there has not been any activity for 7 days.
Maintainer, please provide feedback and/or mark it as Waiting on Author

[ghost]

This pull request has been automatically marked as Review Needed because it has been there has not been any activity for 7 days.
Maintainer, please provide feedback and/or mark it as Waiting on Author

[SteveL-MSFT]

LGTM

[iSazonov]

/rebase

[github-actions]

Started rebase: https://github.com/PowerShell/PowerShell/actions/runs/2343284398

GitHub

Show optional parameters as such when dislplaying method definition and overloads · PowerShell/PowerShell@3f35800

PowerShell for every system! Contribute to PowerShell/PowerShell development by creating an account on GitHub.

[iSazonov]

@TravisEz13 Could you please look the rebase error? https://github.com/PowerShell/PowerShell/runs/6483334261?check_suite_focus=true#step:5:31

GitHub

Show optional parameters as such when dislplaying method definition and overloads · PowerShell/PowerShell@3f35800

PowerShell for every system! Contribute to PowerShell/PowerShell development by creating an account on GitHub.

[ghost]

This pull request has been automatically marked as Review Needed because it has been there has not been any activity for 7 days.
Maintainer, please provide feedback and/or mark it as Waiting on Author

[ghost]

🎉v7.3.0-preview.6 has been released which incorporates this pull request.:tada:

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