Offer 'readonly' completion in type contexts #26186

jcouv · 2018-04-17T04:36:17Z

Customer scenario

Type "public" then expect that you are offered a completion for "readonly", so you can type "public readonly struct". Prior to this PR, the completion was not offered.

Bugs this fixes

Fixes #26120

Workarounds, if any

You can always spell out "readonly" without completion help.

Risk & Performance impact

Low. This follows the same pattern used for "public" and other similar keyword recommenders.

Is this a regression from a previous update?

No. "readonly struct" is a new feature in 15.7.

Root cause analysis

This was missed in the IDE test pass.

How was the bug found?

Reported by customer.

CyrusNajmabadi · 2018-04-17T18:15:59Z

src/Features/CSharp/Portable/Completion/KeywordRecommenders/ReadOnlyKeywordRecommender.cs

+        private static bool IsValidContextForType(CSharpSyntaxContext context, CancellationToken cancellationToken)
+        {
+            return context.IsTypeDeclarationContext(validModifiers: SyntaxKindSet.AllTypeModifiers,
+                validTypeDeclarations: SyntaxKindSet.ClassStructTypeDeclarations, canBePartial: false, cancellationToken);


can't have a partial readonly struct?

can you have a readonly class? should this just be valid on StructTypeDecls?

Good catch. Fixed the partial case.

validTypeDeclarations is correct though. It checks the containing type declaration. A readonly struct can be declared inside a class or a struct (there are tests for that).

Gotcha. Thanks!

Neme12 · 2018-04-18T11:22:21Z

src/EditorFeatures/CSharpTest2/Recommendations/ReadOnlyKeywordRecommenderTests.cs

        {
-            await VerifyAbsenceAsync(
-@"new $$");
+            await VerifyKeywordAsync(SourceCodeKind.Regular, @"new $$");


when is it legal to type readonly after new?

ah.. i see, i thought this was object creation

but this test is still a little odd.. this code would be incorrect outside a class/struct

@Neme12 It is not a requirement for completion to strictly only offer was is allowed. It's better to offer a bit too much than bit too little.

@jcouv I didn't mean that you have to change the behavior and add a test to make sure it's not offered here. I just think it would be better to test this in a scenario where it makes sense (inside a class). I don't care if it's offered here or not. But I know we do care it's offered inside a class after new.

Thanks for clarifying.
What's the scenario where new readonly is useful inside a class?

class B { protected struct S { } } class C : B { new readonly struct S { } }

class OuterClass { public struct InnerStruct { } class InnerClass : OuterClass { public new readonly struct InnerStruct { } } }

Note: this is super corner case. i personally wouldn't care much if this didn't happen, or came later.

Thanks. I expect it will just work. I'll add a test

Neme12 · 2018-04-18T11:27:17Z

I think there is the same issue with ref not offered for ref struct. When that gets fixed, we should check that things like "readonly ref struct" work as well.

Neme12 · 2018-04-18T11:27:36Z

Also, did you check that the "struct" keyword is offered after readonly?

Neme12 · 2018-04-18T16:38:03Z

At the same time, please make sure struct is not offered in these places:

class C
{
    void M()
    {
        ref $$
        ref readonly $$
        ref var x = ref $$
    }
}

jcouv · 2018-04-18T17:59:46Z

@Neme12 I'll update the PR to make sure that ref is offered (for typing ref struct and readonly ref struct) and that struct is offered (for ref struct, readonly struct and readonly ref struct).

I don't plan to tighten the completion though (readonly may be offered in some places where it's inappropriate). Not only is that lower priority, from my understanding, but I also suspect that is an existing problem, since I mimicked the behavior for public and private keywords.

Neme12 · 2018-04-19T13:45:14Z

src/EditorFeatures/CSharpTest2/Recommendations/StructKeywordRecommenderTests.cs

+        public async Task TestAfterReadonlyInMethod()
+        {
+            // struct is not useful here, but offered anyways
+            await VerifyAbsenceAsync(SourceCodeKind.Regular,


"offered anyways" VerifyAbsence?

Good catch. Thanks

but in cases above in TestAfterReadonlyRef, TestAfterRef etc it should be offered right?

It should be fixed now. Thanks!

jcouv · 2018-04-26T16:21:28Z

@dotnet/roslyn-ide for review. Thanks

sharwell · 2018-04-27T19:10:48Z

src/Features/CSharp/Portable/Completion/KeywordRecommenders/StructKeywordRecommender.cs

-                SyntaxKind.UnsafeKeyword
+                SyntaxKind.UnsafeKeyword,
+                SyntaxKind.RefKeyword,
+                SyntaxKind.ReadOnlyKeyword


💡 Include a , at the end of the list, so if we ever have to add items to the end of the list the diff doesn't need to show a change on this line (see e.g. how it would have been better if the line with UnsafeKeyword did not need to change here).

sharwell · 2018-04-27T19:13:06Z

src/Workspaces/CSharp/Portable/Extensions/SyntaxTreeExtensions.cs

@@ -53,6 +53,7 @@ internal static partial class SyntaxTreeExtensions
                    case SyntaxKind.VolatileKeyword:
                    case SyntaxKind.UnsafeKeyword:
                    case SyntaxKind.AsyncKeyword:
+                    case SyntaxKind.RefKeyword:


💭 Why are InKeyword, OutKeyword, and ThisKeyword not part of this?

those are not considered modifiers in the sense of how this function is working. This is for the modifiers you get on a member or type decl. The method could have its name update accordingly though.

dpoeschl · 2018-04-27T20:57:15Z

retest windows_debug_unit32_prtest please
Retest reason: jenkins build was gone

jcouv · 2018-05-02T04:47:09Z

@jinujoseph for ask-mode approval for 15.8. Thanks

jcouv · 2018-05-02T16:03:50Z

@jinujoseph for ask-mode approval for 15.8. Thanks

Offer 'readonly' completion in type contexts

c407972

jcouv added the Area-IDE label Apr 17, 2018

jcouv added this to the 15.8 milestone Apr 17, 2018

jcouv self-assigned this Apr 17, 2018

jcouv requested a review from a team as a code owner April 17, 2018 04:36

CyrusNajmabadi reviewed Apr 17, 2018

View reviewed changes

Fix partial case

e3a635d

CyrusNajmabadi approved these changes Apr 18, 2018

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Neme12 reviewed Apr 18, 2018

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jcouv added 2 commits April 18, 2018 19:49

Add tests

515c1d8

Fix a few remaining scenarios with ref and readonly

6a37973

jcouv force-pushed the readonly-completion branch from 16ff7bb to 6a37973 Compare April 19, 2018 13:41

Neme12 reviewed Apr 19, 2018

View reviewed changes

Remove incorrect comment

26e615b

jcouv added the PR For Personal Review Only The PR doesn’t require anyone other than the developer to review it. label Apr 19, 2018

Fix struct completion after ref and readonly ref

ff60468

jcouv force-pushed the readonly-completion branch from 4ff5794 to ff60468 Compare April 20, 2018 02:22

jcouv removed the PR For Personal Review Only The PR doesn’t require anyone other than the developer to review it. label Apr 20, 2018

jinujoseph assigned dpoeschl Apr 26, 2018

sharwell approved these changes Apr 27, 2018

View reviewed changes

dpoeschl approved these changes Apr 27, 2018

View reviewed changes

jinujoseph added the Approved to merge label May 2, 2018

jcouv merged commit 8424006 into dotnet:master May 2, 2018

jcouv deleted the readonly-completion branch May 2, 2018 16:19

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Offer 'readonly' completion in type contexts #26186

Offer 'readonly' completion in type contexts #26186

jcouv commented Apr 17, 2018

CyrusNajmabadi Apr 17, 2018

jcouv Apr 18, 2018

CyrusNajmabadi Apr 18, 2018

Neme12 Apr 18, 2018

Neme12 Apr 18, 2018

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jcouv commented May 2, 2018

jcouv commented May 2, 2018

Offer 'readonly' completion in type contexts #26186

Offer 'readonly' completion in type contexts #26186

Conversation

jcouv commented Apr 17, 2018

Customer scenario

Bugs this fixes

Workarounds, if any

Risk & Performance impact

Is this a regression from a previous update?

Root cause analysis

How was the bug found?

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Neme12 commented Apr 18, 2018

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jcouv commented Apr 26, 2018

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dpoeschl commented Apr 27, 2018 • edited Loading

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