Merge pull request #1357 from dotnet/dev/bartde/rx_nullable_part14

bartdesmet · web-flow · commit b1146e754917 · 2020-10-02T12:12:38.000-07:00
Enable #nullable for push-pull adapters.
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Collect.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Collect.cs
@@ -2,7 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT License.
 // See the LICENSE file in the project root for more information. 
 
-#nullable disable
+using System.Diagnostics.CodeAnalysis;
 
 namespace System.Reactive.Linq.ObservableImpl
 {
@@ -37,7 +37,7 @@ public _(Func<TResult, TSource, TResult> merge, Func<TResult, TResult> getNewCol
             }
 
             private TResult _collector;
-            private Exception _error;
+            private Exception? _error;
             private bool _hasCompleted;
             private bool _done;
 
@@ -78,15 +78,15 @@ public override void OnCompleted()
                 }
             }
 
-            public override bool TryMoveNext(out TResult current)
+            public override bool TryMoveNext([MaybeNullWhen(false)] out TResult current)
             {
                 lock (_gate)
                 {
                     var error = _error;
                     if (error != null)
                     {
                         current = default;
-                        _collector = default;
+                        _collector = default!;
                         error.Throw();
                     }
                     else
@@ -96,7 +96,7 @@ public override bool TryMoveNext(out TResult current)
                             if (_done)
                             {
                                 current = default;
-                                _collector = default;
+                                _collector = default!;
                                 return false;
                             }
 
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Latest.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Latest.cs
@@ -2,8 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT License.
 // See the LICENSE file in the project root for more information. 
 
-#nullable disable
-
+using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 
 namespace System.Reactive.Linq.ObservableImpl
@@ -33,8 +32,8 @@ public _()
 
             private bool _notificationAvailable;
             private NotificationKind _kind;
-            private TSource _value;
-            private Exception _error;
+            private TSource? _value;
+            private Exception? _error;
 
             public override void OnNext(TSource value)
             {
@@ -90,7 +89,7 @@ public override void OnCompleted()
                 }
             }
 
-            public override bool TryMoveNext(out TSource current)
+            public override bool TryMoveNext([MaybeNullWhen(false)] out TSource current)
             {
                 NotificationKind kind;
 
@@ -119,10 +118,10 @@ public override bool TryMoveNext(out TSource current)
                 switch (kind)
                 {
                     case NotificationKind.OnNext:
-                        current = value;
+                        current = value!;
                         return true;
                     case NotificationKind.OnError:
-                        error.Throw();
+                        error!.Throw();
                         break;
                     case NotificationKind.OnCompleted:
                         break;
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/MostRecent.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/MostRecent.cs
@@ -2,7 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT License.
 // See the LICENSE file in the project root for more information. 
 
-#nullable disable
+using System.Diagnostics.CodeAnalysis;
 
 namespace System.Reactive.Linq.ObservableImpl
 {
@@ -31,7 +31,7 @@ public _(TSource initialValue)
 
             private volatile NotificationKind _kind;
             private TSource _value;
-            private Exception _error;
+            private Exception? _error;
 
             public override void OnNext(TSource value)
             {
@@ -54,7 +54,7 @@ public override void OnCompleted()
                 _kind = NotificationKind.OnCompleted;  // Write last!
             }
 
-            public override bool TryMoveNext(out TSource current)
+            public override bool TryMoveNext([MaybeNullWhen(false)]out TSource current)
             {
                 //
                 // Notice the _kind field is marked volatile and read before the other fields.
@@ -68,7 +68,7 @@ public override bool TryMoveNext(out TSource current)
                         current = _value;
                         return true;
                     case NotificationKind.OnError:
-                        _error.Throw();
+                        _error!.Throw();
                         break;
                     case NotificationKind.OnCompleted:
                         break;
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/Next.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/Next.cs
@@ -2,8 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT License.
 // See the LICENSE file in the project root for more information. 
 
-#nullable disable
-
+using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 
 namespace System.Reactive.Linq.ObservableImpl
@@ -15,10 +14,7 @@ public Next(IObservable<TSource> source)
         {
         }
 
-        protected override PushToPullSink<TSource, TSource> Run()
-        {
-            return new _();
-        }
+        protected override PushToPullSink<TSource, TSource> Run() => new _();
 
         private sealed class _ : PushToPullSink<TSource, TSource>
         {
@@ -33,8 +29,8 @@ public _()
 
             private bool _waiting;
             private NotificationKind _kind;
-            private TSource _value;
-            private Exception _error;
+            private TSource? _value;
+            private Exception? _error;
 
             public override void OnNext(TSource value)
             {
@@ -92,7 +88,7 @@ public override void OnCompleted()
                 }
             }
 
-            public override bool TryMoveNext(out TSource current)
+            public override bool TryMoveNext([MaybeNullWhen(false)] out TSource current)
             {
                 var done = false;
 
@@ -127,10 +123,10 @@ public override bool TryMoveNext(out TSource current)
                 switch (_kind)
                 {
                     case NotificationKind.OnNext:
-                        current = _value;
+                        current = _value!;
                         return true;
                     case NotificationKind.OnError:
-                        _error.Throw();
+                        _error!.Throw();
                         break;
                     case NotificationKind.OnCompleted:
                         break;
diff --git a/Rx.NET/Source/src/System.Reactive/Linq/Observable/PushToPullAdapter.cs b/Rx.NET/Source/src/System.Reactive/Linq/Observable/PushToPullAdapter.cs
@@ -2,10 +2,9 @@
 // The .NET Foundation licenses this file to you under the MIT License.
 // See the LICENSE file in the project root for more information. 
 
-#nullable disable
-
 using System.Collections;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Reactive.Disposables;
 
 namespace System.Reactive.Linq.ObservableImpl
@@ -33,13 +32,13 @@ public IEnumerator<TResult> GetEnumerator()
 
     internal abstract class PushToPullSink<TSource, TResult> : IObserver<TSource>, IEnumerator<TResult>
     {
-        private IDisposable _upstream;
+        private IDisposable? _upstream;
 
         public abstract void OnNext(TSource value);
         public abstract void OnError(Exception error);
         public abstract void OnCompleted();
 
-        public abstract bool TryMoveNext(out TResult current);
+        public abstract bool TryMoveNext([MaybeNullWhen(false)] out TResult current);
 
         private bool _done;
 
@@ -60,13 +59,15 @@ public bool MoveNext()
             return false;
         }
 
+#nullable disable // NB: Matches the protocol around accessing Current only if MoveNext returns true.
         public TResult Current
         {
             get;
             private set;
         }
 
         object IEnumerator.Current => Current;
+#nullable restore
 
         public void Reset()
         {

Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@`
`2`	`2`	`// The .NET Foundation licenses this file to you under the MIT License.`
`3`	`3`	`// See the LICENSE file in the project root for more information.`
`4`	`4`
`5`		`-#nullable disable`
	`5`	`+using System.Diagnostics.CodeAnalysis;`
`6`	`6`
`7`	`7`	`namespace System.Reactive.Linq.ObservableImpl`
`8`	`8`	`{`
`@@ -37,7 +37,7 @@ public _(Func<TResult, TSource, TResult> merge, Func<TResult, TResult> getNewCol`
`37`	`37`	`}`
`38`	`38`
`39`	`39`	`private TResult _collector;`
`40`		`- private Exception _error;`
	`40`	`+ private Exception? _error;`
`41`	`41`	`private bool _hasCompleted;`
`42`	`42`	`private bool _done;`
`43`	`43`
`@@ -78,15 +78,15 @@ public override void OnCompleted()`
`78`	`78`	`}`
`79`	`79`	`}`
`80`	`80`
`81`		`- public override bool TryMoveNext(out TResult current)`
	`81`	`+ public override bool TryMoveNext([MaybeNullWhen(false)] out TResult current)`
`82`	`82`	`{`
`83`	`83`	`lock (_gate)`
`84`	`84`	`{`
`85`	`85`	`var error = _error;`
`86`	`86`	`if (error != null)`
`87`	`87`	`{`
`88`	`88`	`current = default;`
`89`		`- _collector = default;`
	`89`	`+ _collector = default!;`
`90`	`90`	`error.Throw();`
`91`	`91`	`}`
`92`	`92`	`else`
`@@ -96,7 +96,7 @@ public override bool TryMoveNext(out TResult current)`
`96`	`96`	`if (_done)`
`97`	`97`	`{`
`98`	`98`	`current = default;`
`99`		`- _collector = default;`
	`99`	`+ _collector = default!;`
`100`	`100`	`return false;`
`101`	`101`	`}`
`102`	`102`
Original file line number	Diff line number	Diff line change
`@@ -2,8 +2,7 @@`
`2`	`2`	`// The .NET Foundation licenses this file to you under the MIT License.`
`3`	`3`	`// See the LICENSE file in the project root for more information.`
`4`	`4`
`5`		`-#nullable disable`
`6`		`-`
	`5`	`+using System.Diagnostics.CodeAnalysis;`
`7`	`6`	`using System.Threading;`
`8`	`7`
`9`	`8`	`namespace System.Reactive.Linq.ObservableImpl`
`@@ -15,10 +14,7 @@ public Next(IObservable<TSource> source)`
`15`	`14`	`{`
`16`	`15`	`}`
`17`	`16`
`18`		`- protected override PushToPullSink<TSource, TSource> Run()`
`19`		`- {`
`20`		`- return new _();`
`21`		`- }`
	`17`	`+ protected override PushToPullSink<TSource, TSource> Run() => new _();`
`22`	`18`
`23`	`19`	`private sealed class _ : PushToPullSink<TSource, TSource>`
`24`	`20`	`{`
`@@ -33,8 +29,8 @@ public _()`
`33`	`29`
`34`	`30`	`private bool _waiting;`
`35`	`31`	`private NotificationKind _kind;`
`36`		`- private TSource _value;`
`37`		`- private Exception _error;`
	`32`	`+ private TSource? _value;`
	`33`	`+ private Exception? _error;`
`38`	`34`
`39`	`35`	`public override void OnNext(TSource value)`
`40`	`36`	`{`
`@@ -92,7 +88,7 @@ public override void OnCompleted()`
`92`	`88`	`}`
`93`	`89`	`}`
`94`	`90`
`95`		`- public override bool TryMoveNext(out TSource current)`
	`91`	`+ public override bool TryMoveNext([MaybeNullWhen(false)] out TSource current)`
`96`	`92`	`{`
`97`	`93`	`var done = false;`
`98`	`94`
`@@ -127,10 +123,10 @@ public override bool TryMoveNext(out TSource current)`
`127`	`123`	`switch (_kind)`
`128`	`124`	`{`
`129`	`125`	`case NotificationKind.OnNext:`
`130`		`- current = _value;`
	`126`	`+ current = _value!;`
`131`	`127`	`return true;`
`132`	`128`	`case NotificationKind.OnError:`
`133`		`- _error.Throw();`
	`129`	`+ _error!.Throw();`
`134`	`130`	`break;`
`135`	`131`	`case NotificationKind.OnCompleted:`
`136`	`132`	`break;`