Null member access operators `?.` and `?[]` by adityapatwardhan · Pull Request #10960 · PowerShell/PowerShell

adityapatwardhan · 2019-11-01T00:04:31Z

PR Summary

PR for ?. and ?[] operators.
Braces need around variable name. Like ${x}?.Name and ${x}?.Get()
Implementation on RFC - PowerShell/PowerShell-RFC#223

PR Context

The null conditional member access operators allow to check the item for being null before a property is accessed or an index is used or a method is invoked. This helps reduced the null checking logic from scripts.

PR Checklist

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs

adityapatwardhan · 2019-11-12T01:08:19Z

@PoshChan please retry Windows

PoshChan · 2019-11-12T01:08:32Z

@adityapatwardhan, successfully started retry of PowerShell-CI-Windows

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

daxian-dbw · 2019-11-12T22:29:21Z

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

Remove trailing spaces here.

Not fixed yet.

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

daxian-dbw · 2019-11-12T23:26:19Z

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

In C#, there is no point to support ?. for member access to static members, but in PowerShell, you can do $a = [string]; $a::Equals(...), which makes it debatable whether we want to support it.

Though it is technically possible to implement something like: $a = [string]; ${a}?::Equals(...), i doubt there is any usefulness to this.

Yeah, it's technically possible. I vote for postponing it until we have a ask. @SteveL-MSFT any thoughts?

Though it is technically possible to implement something like: $a = [string]; ${a}?::Equals(...), i doubt there is any usefulness to this.

Where I think it would be most useful is situations where you want to invoke a static method only if an assembly is already loaded. e.g.

('MyCustomType' -as [type])?::Initialize()

That certainly beats my current method! (and has better utility, probably, as well)

switch ($null) { ('typename' -as [type]) { . Type.ps1 } ('type2name' -as [type]) { . Type2.ps1 } }

Since it's additive we can postpone

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

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

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs

adityapatwardhan · 2019-11-13T23:00:22Z

@daxian-dbw - Please re-review.

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

daxian-dbw · 2019-11-14T00:57:08Z

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

Not fixed yet.

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

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

src/System.Management.Automation/resources/ParserStrings.resx

daxian-dbw · 2019-11-14T01:53:40Z

@rjmholt and @JamesWTruher Can you please review this PR as well? Thanks!

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

PoshChan · 2019-11-14T19:40:08Z

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs

@@ -404,6 +404,7 @@ internal List<CompletionResult> GetResultHelper(CompletionContext completionCont



@adityapatwardhan, your last commit had 1 failures in PowerShell-CI-windows
Enter-PSHostProcess tests.By Process Id.Can enter using NamedPipeConnectionInfo

Exception calling "Invoke" with "0" argument(s): "The runspace state is not valid for this operation." at <ScriptBlock>, D:\a\1\s\test\powershell\Modules\Microsoft.PowerShell.Core\Enter-PSHostProcess.Tests.ps1: line 136 136: $ps.AddScript('$pid').Invoke() | Should -Be $pwshId

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

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

test/powershell/Language/Operators/NullConditional.Tests.ps1

PoshChan · 2019-11-15T00:47:23Z

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs

@@ -404,6 +404,7 @@ internal List<CompletionResult> GetResultHelper(CompletionContext completionCont



@adityapatwardhan, your last commit had 1 failures in PowerShell-CI-windows
NullConditionalMemberAccess.?. operator tests.Use ?. on a dynamic method name that does not exist

Expected an exception, with FullyQualifiedErrorId 'Argument' to be thrown, but the FullyQualifiedErrorId was 'MethodNotFound'. from D:\a\1\s\test\powershell\Language\Operators\NullConditional.Tests.ps1:343 char:15 + { (Get-Date '11/11/2019')?.$methodName() } | Should -Thro ? + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ at <ScriptBlock>, D:\a\1\s\test\powershell\Language\Operators\NullConditional.Tests.ps1: line 343 343: { (Get-Date '11/11/2019')?.$methodName() } | Should -Throw -ErrorId 'Argument'

PoshChan · 2019-11-15T00:47:25Z

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs

@@ -404,6 +404,7 @@ internal List<CompletionResult> GetResultHelper(CompletionContext completionCont



@adityapatwardhan, your last commit had 1 failures in PowerShell-CI-linux
NullConditionalMemberAccess.?. operator tests.Use ?. on a dynamic method name that does not exist

Expected an exception, with FullyQualifiedErrorId 'Argument' to be thrown, but the FullyQualifiedErrorId was 'MethodNotFound'. from /home/vsts/work/1/s/test/powershell/Language/Operators/NullConditional.Tests.ps1:343 char:15 + { (Get-Date '11/11/2019')?.$methodName() } | Should -Thro ? + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ at <ScriptBlock>, /home/vsts/work/1/s/test/powershell/Language/Operators/NullConditional.Tests.ps1: line 343 343: { (Get-Date '11/11/2019')?.$methodName() } | Should -Throw -ErrorId 'Argument'

PoshChan · 2019-11-15T00:50:57Z

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs

@@ -404,6 +404,7 @@ internal List<CompletionResult> GetResultHelper(CompletionContext completionCont



@adityapatwardhan, your last commit had 1 failures in PowerShell-CI-macos
NullConditionalMemberAccess.?. operator tests.Use ?. on a dynamic method name that does not exist

Expected an exception, with FullyQualifiedErrorId 'Argument' to be thrown, but the FullyQualifiedErrorId was 'MethodNotFound'. from /Users/runner/runners/2.160.0/work/1/s/test/powershell/Language/Operators/NullConditional.Tests.ps1:343 char:15 + { (Get-Date '11/11/2019')?.$methodName() } | Should -Thro ? + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ at <ScriptBlock>, /Users/runner/runners/2.160.0/work/1/s/test/powershell/Language/Operators/NullConditional.Tests.ps1: line 343 343: { (Get-Date '11/11/2019')?.$methodName() } | Should -Throw -ErrorId 'Argument'

PoshChan · 2019-11-15T18:29:11Z

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs

@@ -404,6 +404,7 @@ internal List<CompletionResult> GetResultHelper(CompletionContext completionCont



@adityapatwardhan, your last commit had 20 failures in PowerShell-CI-static-analysis
(These are 5 of the failures)

Verify Markdown Links.Verify links in /home/vsts/work/1/s/README.md.https://docs.microsoft.com/powershell/scripting/setup/installing-powershell-core-on-windows?view=powershell-6 should work

retry of URL failed with error: Response status code does not indicate success: 404 (Not Found). at <ScriptBlock>, /home/vsts/work/1/s/test/common/markdown/markdown-link.tests.ps1: line 117 117: throw "retry of URL failed with error: $($_.Exception.Message)"

Verify Markdown Links.Verify links in /home/vsts/work/1/s/README.md.https://docs.microsoft.com/powershell/scripting/setup/installing-powershell-core-on-linux?view=powershell-6#ubuntu-1804 should work

retry of URL failed with error: Response status code does not indicate success: 404 (Not Found). at <ScriptBlock>, /home/vsts/work/1/s/test/common/markdown/markdown-link.tests.ps1: line 117 117: throw "retry of URL failed with error: $($_.Exception.Message)"

Verify Markdown Links.Verify links in /home/vsts/work/1/s/README.md.https://docs.microsoft.com/powershell/scripting/setup/installing-powershell-core-on-linux?view=powershell-6#ubuntu-1604 should work

retry of URL failed with error: Response status code does not indicate success: 404 (Not Found). at <ScriptBlock>, /home/vsts/work/1/s/test/common/markdown/markdown-link.tests.ps1: line 117 117: throw "retry of URL failed with error: $($_.Exception.Message)"

Verify Markdown Links.Verify links in /home/vsts/work/1/s/README.md.https://docs.microsoft.com/powershell/scripting/setup/installing-powershell-core-on-linux?view=powershell-6#debian-9 should work

retry of URL failed with error: Response status code does not indicate success: 404 (Not Found). at <ScriptBlock>, /home/vsts/work/1/s/test/common/markdown/markdown-link.tests.ps1: line 117 117: throw "retry of URL failed with error: $($_.Exception.Message)"

Verify Markdown Links.Verify links in /home/vsts/work/1/s/README.md.https://docs.microsoft.com/powershell/scripting/setup/installing-powershell-core-on-linux?view=powershell-6#centos-7 should work

retry of URL failed with error: Response status code does not indicate success: 404 (Not Found). at <ScriptBlock>, /home/vsts/work/1/s/test/common/markdown/markdown-link.tests.ps1: line 117 117: throw "retry of URL failed with error: $($_.Exception.Message)"

daxian-dbw

One open issue: [System.DBNull]::Value?.GetTypeCode() and [NullString]::Value?.GetType() will return nothing, which might raise confusion. We need to discuss and decide if it's fine to have this semantics for the null-conditional operator.
Talked with @adityapatwardhan offline, and we will discuss and address this in the RC release.
/cc @JamesWTruher @SteveL-MSFT @rjmholt

adityapatwardhan · 2019-11-15T19:48:23Z

Filed issue: #11084

adityapatwardhan · 2019-11-15T20:07:49Z

@PoshChan please retry static

PoshChan · 2019-11-15T20:08:24Z

@adityapatwardhan, successfully started retry of PowerShell-CI-static-analysis

adityapatwardhan · 2019-11-15T20:30:02Z

@daxian-dbw Ready to merge?

ghost · 2019-11-21T22:35:58Z

🎉v7.0.0-preview.6 has been released which incorporates this pull request.:tada:

Handy links:

Release Notes

adityapatwardhan requested review from daxian-dbw and rjmholt November 1, 2019 00:04

PoshChan reviewed Nov 5, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

adityapatwardhan changed the title ~~WIP: Null member access operators ?. and ?[]~~ Null member access operators ?. and ?[] Nov 12, 2019

adityapatwardhan marked this pull request as ready for review November 12, 2019 00:48

PoshChan reviewed Nov 12, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

adityapatwardhan mentioned this pull request Nov 12, 2019

Possible update to syntax highlighting for ?? ??= ?. ?[] operators PowerShell/EditorSyntax#185

Open

adityapatwardhan assigned daxian-dbw Nov 12, 2019

daxian-dbw reviewed Nov 12, 2019

View reviewed changes

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs Outdated Show resolved Hide resolved

adityapatwardhan added 13 commits November 13, 2019 12:52

Working ?. for member and member invoke

fa7e3a2

Remove extra line

5b55dba

InvokeMemberExpression in compiler

f226a4b

Reverting Binder changes

345f687

?[] working

ea0364f

Fix issue with return value of indexed member

a73d726

Fix issue with assigning null members

a453d25

Fix experimental feature condition

67b1317

Fix bug in ?.()

a2d6723

Add tests

f946cbb

CodeFactor fixes

cbbacd3

More CodeFactor fixes

9d02ad2

Add one more test

36177cf

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs Show resolved Hide resolved

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs Show resolved Hide resolved

PoshChan reviewed Nov 13, 2019

View reviewed changes

src/System.Management.Automation/engine/CommandCompletion/CompletionAnalysis.cs Show resolved Hide resolved

Fix bug introduced in refactoring

51e0453

daxian-dbw reviewed Nov 14, 2019

View reviewed changes

rjmholt reviewed Nov 14, 2019

View reviewed changes

src/System.Management.Automation/engine/parser/Compiler.cs Outdated Show resolved Hide resolved

src/System.Management.Automation/engine/parser/Compiler.cs Outdated Show resolved Hide resolved

Address code review comments

f75f71b

PoshChan reviewed Nov 14, 2019

View reviewed changes

adityapatwardhan added 3 commits November 14, 2019 11:51

Fix null conditional access to dyamic method and add test

b27a8f2

Replace Expression.IfThenElse condition with Expression.Condition

a39ae8d

Change Semantics checks to be done in CheckAssignmentTarget

b3a94dd

daxian-dbw reviewed Nov 14, 2019

View reviewed changes

src/System.Management.Automation/engine/parser/Compiler.cs Outdated Show resolved Hide resolved

src/System.Management.Automation/engine/parser/SemanticChecks.cs Outdated Show resolved Hide resolved

test/powershell/Language/Operators/NullConditional.Tests.ps1 Show resolved Hide resolved

Add more tests for dynamic method name or property

50764c7

PoshChan reviewed Nov 15, 2019

View reviewed changes

Fix expected error ID

6d3af7f

PoshChan reviewed Nov 15, 2019

View reviewed changes

daxian-dbw approved these changes Nov 15, 2019

View reviewed changes

daxian-dbw merged commit 2579c00 into PowerShell:master Nov 16, 2019

SteveL-MSFT added this to the 7.0.0-preview.6 milestone Nov 18, 2019

SteveL-MSFT added the CL-Experimental Indicates that a PR should be marked as an Experimental Feature in the Change Log label Nov 18, 2019

adityapatwardhan deleted the NullMemberAccessOperators branch June 8, 2020 18:24

		@@ -404,6 +404,7 @@ internal List<CompletionResult> GetResultHelper(CompletionContext completionCont

Conversation

adityapatwardhan commented Nov 1, 2019 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

PR Summary

PR Context

PR Checklist

Uh oh!

Uh oh!

Uh oh!

adityapatwardhan commented Nov 12, 2019

Uh oh!

PoshChan commented Nov 12, 2019

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

daxian-dbw Nov 13, 2019 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

vexx32 Nov 14, 2019 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

adityapatwardhan commented Nov 13, 2019

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

daxian-dbw commented Nov 14, 2019

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

adityapatwardhan commented Nov 1, 2019 •

edited

Loading

daxian-dbw Nov 13, 2019 •

edited

Loading

vexx32 Nov 14, 2019 •

edited

Loading

daxian-dbw left a comment •

edited

Loading