🚧Fix bug with null ref exceptions on unsubscribe all (#203)

* Start work for issue #202

* config: added create pr powershell script

* fix: check for null before trying to invoke unsubscribe method

* test: create unit test to test for fix

Carbonate/ReactableBase.cs

@@ -133,6 +133,13 @@ public virtual void UnsubscribeAll()
 
         foreach (TSubscription subscription in CollectionsMarshal.AsSpan(InternalSubscriptions))
         {
+            // NOTE: This suppression is because the items could be null even with nullable reference types enabled.
+            // ReSharper disable ConditionIsAlwaysTrueOrFalseAccordingToNullableAPIContract
+            if (subscription is null)
+            {
+                continue;
+            }
+
             subscription.OnUnsubscribe();
         }
 

Testing/CarbonateIntegrationTests/NonDirectionalPushReactable_IntegrationTests.cs

@@ -20,22 +20,54 @@ public class NonDirectionalPushReactable_IntegrationTests
     public void WhenPushing_And_WithSingleEventID_And_WithSingleSubscription_And_WithSingleUnsubscribe_ReturnsCorrectResults()
     {
         // Arrange
-        var eventId = new Guid("98a879d4-e819-41da-80e4-a1b459b3e43f");
+        var id = new Guid("98a879d4-e819-41da-80e4-a1b459b3e43f");
 
         IDisposable? unsubscriber = null;
 
-        var reactable = new PushReactable();
+        var sut = new PushReactable();
 
-        unsubscriber = reactable.Subscribe(new ReceiveSubscription(
-            id: eventId,
+        unsubscriber = sut.Subscribe(new ReceiveSubscription(
+            id: id,
             onReceive: () => { },
             onUnsubscribe: () => unsubscriber?.Dispose()));
 
         // Act
-        reactable.Push(eventId);
-        reactable.Unsubscribe(eventId);
+        sut.Push(id);
+        sut.Unsubscribe(id);
 
         // Assert
-        reactable.Subscriptions.Should().HaveCount(0);
+        sut.Subscriptions.Should().HaveCount(0);
+    }
+
+    [Fact]
+    public void Unsubscribing_BeforeCallingUnsubscribeAll_DoesNotThrowException()
+    {
+        // Arrange
+        var id = new Guid("f227d62c-1830-4a42-a5b3-3c920779bf94");
+        IDisposable? unsubscriberB = null;
+        var sut = new PushReactable();
+
+        sut.Subscribe(
+            new ReceiveSubscription(
+                id: id,
+                onReceive: () => { },
+                onUnsubscribe: () =>
+                {
+                    // Unsubscribe from the second subscription so when
+                    // it comes its turn to be unsubscribed, it will be null.
+                    unsubscriberB.Dispose();
+                }));
+
+        unsubscriberB = sut.Subscribe(
+            new ReceiveSubscription(
+                id: id,
+                onReceive: () => { },
+                onUnsubscribe: () => unsubscriberB.Dispose()));
+
+        // Act
+        var act = () => sut.UnsubscribeAll();
+
+        // Assert
+        act.Should().NotThrow();
     }
 }

create-pr.ps1

@@ -0,0 +1,50 @@
+Clear-Host;
+
+Write-Host -NoNewline "Please enter an issue number: " -ForegroundColor Cyan;
+$issueNumber = Read-Host;
+
+if ($issueNumber -notmatch '^\d+$') {
+    Write-Error "User input is not a number";
+    exit 1;
+}
+
+Write-Host -NoNewline "Please enter a branch name: " -ForegroundColor Cyan;
+$branchDescrip = Read-Host;
+
+$branchDescrip = $branchDescrip.ToLower();
+$branchDescrip = $branchDescrip.Replace(" ", "-").Replace("_", "-");
+$branchDescrip = $branchDescrip.TrimStart("-");
+$branchDescrip = $branchDescrip.TrimEnd("-");
+
+$headBranch = "feature/$issueNumber-$branchDescrip";
+$commitMsg = "Start owrk for issue #$issueNumber";
+
+$destBranch = "not-set";
+
+$baseBranches = @("main", "preview");
+Write-Host -NoNewline "Please choose a base branch from the list [$($baseBranches -join ', ')]: " -ForegroundColor Cyan;
+$chosenBaseBranch = Read-Host;
+
+if ($baseBranches -contains $chosenBaseBranch) {
+    $destBranch = $chosenBaseBranch;
+} else {
+    Write-Error "Invalid base branch.";
+    exit 1;
+}
+
+Write-Host "`n--------------------------------`n";
+
+Write-Host "Creating branch. . ." -ForegroundColor Yellow;
+git checkout -B "$headBranch";
+Write-Host "";
+
+Write-Host "Creating empty commit. . ." -ForegroundColor Yellow;
+git commit --allow-empty -m $commitMsg;
+Write-Host "";
+
+Write-Host "Pushing branch to remote. . ." -ForegroundColor Yellow;
+git push --set-upstream origin "$headBranch";
+Write-Host "";
+
+Write-Host "Creating PR. . ." -ForegroundColor Yellow;
+gh pr create -B $destBranch -b "" -t "new pr" -d;