Use more collection expressions

src/Common.AnsiCli/AnsiCli.cs

@@ -68,7 +68,7 @@ public static IRenderable Table<T>(IEnumerable<T> data)
 
             table.AddRow(getters.Select(getter =>
             {
-                var value = getter.Invoke(row, Array.Empty<object?>());
+                var value = getter.Invoke(row, []);
                 return new Text(
                     value?.ToString() ?? "",
                     new Style(foreground, link: (value as Uri)?.ToStringRfc()));

src/Common/Collections/ArrayUtils.cs

@@ -101,9 +101,9 @@ public static T[] AsArray<T>(this ArraySegment<T> segment)
     {
         if (segment.Array == null)
 #if NET20 || NET40 || NET45
-                return new T[0];
+            return new T[0];
 #else
-            return Array.Empty<T>();
+            return [];
 #endif
 
         if (segment.Offset == 0 && segment.Count == segment.Array.Length)

src/Common/Collections/EnumerableExtensions.cs

@@ -145,7 +145,7 @@ public static IEnumerable<T> Except<T>(this IEnumerable<T> enumeration, Func<T,
         /// </summary>
         [LinqTunnel]
         public static IEnumerable<T> Except<T>(this IEnumerable<T> enumeration, T element)
-            => enumeration.Except(new[] {element});
+            => enumeration.Except([element]);
 
         /// <summary>
         /// Flattens a list of lists.

src/Common/Collections/MultiDictionary.cs

@@ -68,5 +68,5 @@ public bool Remove(TKey key, TValue value)
     /// <returns>A list of elements with the specified key. Empty list if the key was not found.</returns>
     [CollectionAccess(CollectionAccessType.Read)]
     public new IEnumerable<TValue> this[TKey key]
-        => TryGetValue(key, out var result) ? result : Enumerable.Empty<TValue>();
+        => TryGetValue(key, out var result) ? result : [];
 }

src/Common/Dispatch/ModelViewSync.cs

@@ -137,6 +137,6 @@ public void Register<TSpecificModel, TSpecificView>(Func<TSpecificModel, TSpecif
     {
         if (create == null) throw new ArgumentNullException(nameof(create));
 
-        RegisterMultiple(element => new[] {create(element)}, update);
+        RegisterMultiple(element => [create(element)], update);
     }
 }

src/Samples/WinForms/MainForm.cs

@@ -23,7 +23,7 @@ public MainForm()
         var outputGridButton = new Button {Text = "Grid", Location = new(90, 100)};
         outputGridButton.Click += delegate
         {
-            OutputGridBox.Show(this, "Test", new [] {"Test 1", "Test 2"});
+            OutputGridBox.Show(this, "Test", ["Test 1", "Test 2"]);
         };
 
         var errorButton = new Button {Text = "Error", Location = new(170, 100)};

src/UnitTests/Collections/MultiDictionaryTest.cs

@@ -19,8 +19,8 @@ public void TestAdd()
             {"B", 0}
         }.Should().BeEquivalentTo(new Dictionary<string, IEnumerable<int>>
         {
-            ["A"] = new[] {0, 1},
-            ["B"] = new[] {0}
+            ["A"] = [0, 1],
+            ["B"] = [0]
         });
     }
 
@@ -32,7 +32,7 @@ public void TestValues()
             {"A", 0},
             {"B", 1},
             {"C", 1}
-        }.Values.Should().BeEquivalentTo(new[] {0, 1, 1});
+        }.Values.Should().BeEquivalentTo([0, 1, 1]);
     }
 
     [Fact]
@@ -51,6 +51,6 @@ public void TestRemove()
         dict.Remove("A", 2).Should().BeFalse();
         dict.Remove("C", 0).Should().BeFalse();
 
-        dict.Should().BeEquivalentTo(new Dictionary<string, IEnumerable<int>> {["A"] = new[] {0}});
+        dict.Should().BeEquivalentTo(new Dictionary<string, IEnumerable<int>> {["A"] = [0]});
     }
-}
+}

src/UnitTests/Dispatch/MergeTest.cs

@@ -61,8 +61,8 @@ public void TestMergeSimple()
         ICollection<int> toRemove = new List<int>();
         ICollection<int> toAdd = new List<int>();
         Merge.TwoWay(
-            theirs: new[] {16, 8, 4},
-            mine: new[] {1, 2, 4},
+            theirs: [16, 8, 4],
+            mine: [1, 2, 4],
             added: toAdd.Add, removed: toRemove.Add);
 
         toAdd.Should().Equal(16, 8);
@@ -77,7 +77,7 @@ public void TestMergeEquals()
     {
         var list = new[] {new MergeTestData(mergeID: "1")};
 
-        Merge.ThreeWay(reference: Array.Empty<MergeTestData>(), theirs: list, mine: list,
+        Merge.ThreeWay(reference: [], theirs: list, mine: list,
             added: element => throw new AssertionFailedException($"{element} should not be detected as added."),
             removed: element => throw new AssertionFailedException($"{element} should not be detected as removed."));
     }
@@ -107,21 +107,21 @@ public void TestMergeAddAndRemove()
     public void TestMergeModify()
     {
         var reference = MergeTestData.BuildList("a", "b", "c", "d", "e");
-        var theirs = new[]
+        var theirs = new MergeTestData[]
         {
-            new MergeTestData(mergeID: "a"),
-            new MergeTestData(mergeID: "b", data: "123", timestamp: new DateTime(2000, 1, 1)),
-            new MergeTestData(mergeID: "c"),
-            new MergeTestData(mergeID: "d", data: "456", timestamp: new DateTime(2000, 1, 1)),
-            new MergeTestData(mergeID: "e", data: "789", timestamp: new DateTime(2999, 1, 1))
+            new(mergeID: "a"),
+            new(mergeID: "b", data: "123", timestamp: new DateTime(2000, 1, 1)),
+            new(mergeID: "c"),
+            new(mergeID: "d", data: "456", timestamp: new DateTime(2000, 1, 1)),
+            new(mergeID: "e", data: "789", timestamp: new DateTime(2999, 1, 1))
         };
-        var mine = new[]
+        var mine = new MergeTestData[]
         {
-            new MergeTestData(mergeID: "a"),
-            new MergeTestData(mergeID: "b"),
-            new MergeTestData(mergeID: "c", data: "abc", timestamp: new DateTime(2000, 1, 1)),
-            new MergeTestData(mergeID: "d", data: "def", timestamp: new DateTime(2999, 1, 1)),
-            new MergeTestData(mergeID: "e", data: "ghi", timestamp: new DateTime(2000, 1, 1))
+            new(mergeID: "a"),
+            new(mergeID: "b"),
+            new(mergeID: "c", data: "abc", timestamp: new DateTime(2000, 1, 1)),
+            new(mergeID: "d", data: "def", timestamp: new DateTime(2999, 1, 1)),
+            new(mergeID: "e", data: "ghi", timestamp: new DateTime(2000, 1, 1))
         };
 
         var toRemove = new List<MergeTestData>();
@@ -131,4 +131,4 @@ public void TestMergeModify()
         toRemove.Should().Equal(mine[1], mine[4]);
         toAdd.Should().Equal(theirs[1], theirs[4]);
     }
-}
+}

src/UnitTests/Tasks/ForEachTaskTest.cs

@@ -25,10 +25,10 @@ public void TestCallback()
     [Fact]
     public void TestExceptionPassing()
     {
-        ForEachTask.Create("Test task", new[] { "" }, _ => throw new IOException("Test exception"))
+        ForEachTask.Create("Test task", [""], _ => throw new IOException("Test exception"))
                    .Invoking(x => x.Run())
                    .Should().Throw<IOException>();
-        ForEachTask.Create("Test task", new[] {""}, _ => throw new WebException("Test exception"))
+        ForEachTask.Create("Test task", [""], _ => throw new WebException("Test exception"))
                    .Invoking(x => x.Run())
                    .Should().Throw<WebException>();
     }
@@ -38,7 +38,7 @@ public void TestRollbackException()
     {
         var applyCalledFor = new List<int>();
         var rollbackCalledFor = new List<int>();
-        ForEachTask.Create("Test task", new[] {1, 2, 3},
+        ForEachTask.Create("Test task", [1, 2, 3],
                         action: value =>
                         {
                             applyCalledFor.Add(value);
@@ -59,7 +59,7 @@ public void TestRollbackCancellation()
 
         var applyCalledFor = new List<int>();
         var rollbackCalledFor = new List<int>();
-        ForEachTask.Create("Test task", new[] {1, 2, 3},
+        ForEachTask.Create("Test task", [1, 2, 3],
                         action: value =>
                         {
                             applyCalledFor.Add(value);

src/UnitTests/Threading/ResultRacerTest.cs

@@ -9,7 +9,7 @@ public class ResultRacerTest
     [Fact]
     public void Sync()
     {
-        var racer = ResultRacer.For(new[] {1, 2, 3}, (i, _) =>
+        var racer = ResultRacer.For([1, 2, 3], (i, _) =>
         {
             Thread.Sleep(i * 100);
             return i;
@@ -20,7 +20,7 @@ public void Sync()
     [Fact]
     public void SyncCancellation()
     {
-        var racer = ResultRacer.For(new[] {1}, (i, _) =>
+        var racer = ResultRacer.For([1], (i, _) =>
         {
             Thread.Sleep(100);
             return i;
@@ -32,7 +32,7 @@ public void SyncCancellation()
     [Fact]
     public async Task Async()
     {
-        var racer = ResultRacer.For(new[] {1, 2, 3}, async (i, cancellationToken) =>
+        var racer = ResultRacer.For([1, 2, 3], async (i, cancellationToken) =>
         {
             await Task.Delay(i * 100, cancellationToken);
             return i;
@@ -43,7 +43,7 @@ public async Task Async()
     [Fact]
     public async Task AsyncCancellation()
     {
-        var racer = ResultRacer.For(new[] {1}, async (i, cancellationToken) =>
+        var racer = ResultRacer.For([1], async (i, cancellationToken) =>
         {
             await Task.Delay(100, cancellationToken);
             return i;

src/UnitTests/Undo/CompositeCommandTest.cs

@@ -34,10 +34,10 @@ public void TestExecuteUndo()
             new MockCommand(() => executeCalls.Add(2), () => undoCalls.Add(2)));
 
         command.Execute();
-        executeCalls.Should().Equal(new[] {0, 1, 2}, because: "Child commands should be executed in ascending order");
+        executeCalls.Should().Equal([0, 1, 2], because: "Child commands should be executed in ascending order");
 
         command.Undo();
-        undoCalls.Should().Equal(new[] {2, 1, 0}, because: "Child commands should be undone in descending order");
+        undoCalls.Should().Equal([2, 1, 0], because: "Child commands should be undone in descending order");
     }
 
     [Fact]
@@ -51,8 +51,8 @@ public void TestExecuteRollback()
             new MockCommand(() => throw new OperationCanceledException(), () => undoCalls.Add(2)));
 
         command.Invoking(x => x.Execute()).Should().Throw<OperationCanceledException>(because: "Exceptions should be passed through after rollback");
-        executeCalls.Should().Equal(new[] {0, 1}, because: "After an exception the rest of the commands should not be executed");
-        undoCalls.Should().Equal(new[] {1, 0}, because: "After an exception all successful executions should be undone");
+        executeCalls.Should().Equal([0, 1], because: "After an exception the rest of the commands should not be executed");
+        undoCalls.Should().Equal([1, 0], because: "After an exception all successful executions should be undone");
     }
 
     [Fact]
@@ -66,12 +66,12 @@ public void TestUndoRollback()
             new MockCommand(() => executeCalls.Add(2), () => undoCalls.Add(2)));
 
         command.Execute();
-        executeCalls.Should().Equal(new[] {0, 1, 2}, because: "Child commands should be executed in ascending order");
+        executeCalls.Should().Equal([0, 1, 2], because: "Child commands should be executed in ascending order");
 
         executeCalls.Clear();
         command.Invoking(x => x.Undo()).Should().Throw<OperationCanceledException>(because: "Exceptions should be passed through after rollback");
-        undoCalls.Should().Equal(new[] {2, 1}, because: "After an exception the rest of the undoes should not be performed");
-        executeCalls.Should().Equal(new[] {1, 2}, because: "After an exception all successful undoes should be re-executed");
+        undoCalls.Should().Equal([2, 1], because: "After an exception the rest of the undoes should not be performed");
+        executeCalls.Should().Equal([1, 2], because: "After an exception all successful undoes should be re-executed");
     }
 
     [Fact]
@@ -83,4 +83,4 @@ public void TestWrongOrder()
         command.Execute();
         command.Invoking(x => x.Execute()).Should().Throw<InvalidOperationException>(because: "Should not allow two Executes without an Undo in between");
     }
-}
+}

src/UnitTests/Undo/PreExecutedCompositeCommandTest.cs

@@ -39,9 +39,9 @@ public void TestExecuteUndo()
         executeCalls.Should().BeEmpty(because: "First execution should do nothing");
 
         command.Undo();
-        undoCalls.Should().Equal(new[] {2, 1, 0}, because: "Child commands should be undone in descending order");
+        undoCalls.Should().Equal([2, 1, 0], because: "Child commands should be undone in descending order");
 
         command.Execute();
-        executeCalls.Should().Equal(new[] {0, 1, 2}, because: "Child commands should be executed in ascending order");
+        executeCalls.Should().Equal([0, 1, 2], because: "Child commands should be executed in ascending order");
     }
-}
+}