aspnetcore/test/Microsoft.AspNetCore.Blazor.../RenderTreeDiffComputerTest.cs

955 lines
38 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using Microsoft.AspNetCore.Blazor.Components;
using Microsoft.AspNetCore.Blazor.Rendering;
using Microsoft.AspNetCore.Blazor.RenderTree;
using Microsoft.AspNetCore.Blazor.Test.Shared;
using System;
using System.Collections.Generic;
using System.Linq;
using Xunit;
namespace Microsoft.AspNetCore.Blazor.Test
{
public class RenderTreeDiffComputerTest
{
private readonly Renderer renderer;
private readonly RenderTreeBuilder oldTree;
private readonly RenderTreeBuilder newTree;
private RenderTreeDiffComputer diff;
public RenderTreeDiffComputerTest()
{
renderer = new FakeRenderer();
oldTree = new RenderTreeBuilder(renderer);
newTree = new RenderTreeBuilder(renderer);
diff = new RenderTreeDiffComputer(renderer);
}
[Theory]
[MemberData(nameof(RecognizesEquivalentFramesAsSameCases))]
public void RecognizesEquivalentFramesAsSame(Action<RenderTreeBuilder> appendAction)
{
// Arrange
appendAction(oldTree);
appendAction(newTree);
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Empty(result.Edits);
}
public static IEnumerable<object[]> RecognizesEquivalentFramesAsSameCases()
=> new Action<RenderTreeBuilder>[]
{
builder => builder.AddText(0, "Hello"),
builder => builder.OpenElement(0, "Some Element"),
builder =>
{
builder.OpenElement(0, "Some Element");
builder.AddAttribute(1, "My attribute", "My value");
builder.CloseElement();
},
builder => builder.OpenComponent<FakeComponent>(0)
}.Select(x => new object[] { x });
[Fact]
public void RecognizesNewItemsBeingInserted()
{
// Arrange
oldTree.AddText(0, "text0");
oldTree.AddText(2, "text2");
newTree.AddText(0, "text0");
newTree.AddText(1, "text1");
newTree.AddText(2, "text2");
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 1);
Assert.Equal(0, entry.ReferenceFrameIndex);
AssertFrame.Text(result.ReferenceFrames.Array[0], "text1", 1);
});
}
[Fact]
public void RecognizesOldItemsBeingRemoved()
{
// Arrange
oldTree.AddText(0, "text0");
oldTree.AddText(1, "text1");
oldTree.AddText(2, "text2");
newTree.AddText(0, "text0");
newTree.AddText(2, "text2");
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 1));
}
[Fact]
public void RecognizesTrailingSequenceWithinLoopBlockBeingRemoved()
{
// Arrange
oldTree.AddText(0, "x"); // Loop start
oldTree.AddText(1, "x"); // Will be removed
oldTree.AddText(2, "x"); // Will be removed
oldTree.AddText(0, "x"); // Loop start
newTree.AddText(0, "x"); // Loop start
newTree.AddText(0, "x"); // Loop start
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 1),
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 1));
}
[Fact]
public void RecognizesTrailingSequenceWithinLoopBlockBeingAppended()
{
// Arrange
oldTree.AddText(10, "x"); // Loop start
oldTree.AddText(10, "x"); // Loop start
newTree.AddText(10, "x"); // Loop start
newTree.AddText(11, "x"); // Will be added
newTree.AddText(12, "x"); // Will be added
newTree.AddText(10, "x"); // Loop start
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 1);
Assert.Equal(0, entry.ReferenceFrameIndex);
},
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 2);
Assert.Equal(1, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Text(frame, "x", 11),
frame => AssertFrame.Text(frame, "x", 12));
}
[Fact]
public void RecognizesTrailingLoopBlockBeingRemoved()
{
// Arrange
oldTree.AddText(0, "x");
oldTree.AddText(1, "x");
oldTree.AddText(0, "x"); // Will be removed
oldTree.AddText(1, "x"); // Will be removed
newTree.AddText(0, "x");
newTree.AddText(1, "x");
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 2),
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 2));
}
[Fact]
public void RecognizesTrailingLoopBlockBeingAdded()
{
// Arrange
oldTree.AddText(10, "x");
oldTree.AddText(11, "x");
newTree.AddText(10, "x");
newTree.AddText(11, "x");
newTree.AddText(10, "x"); // Will be added
newTree.AddText(11, "x"); // Will be added
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 2);
Assert.Equal(0, entry.ReferenceFrameIndex);
},
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 3);
Assert.Equal(1, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Text(frame, "x", 10),
frame => AssertFrame.Text(frame, "x", 11));
}
[Fact]
public void RecognizesLeadingLoopBlockItemsBeingAdded()
{
// Arrange
oldTree.AddText(12, "x");
oldTree.AddText(12, "x"); // Note that the '0' and '1' items are not present on this iteration
newTree.AddText(12, "x");
newTree.AddText(10, "x");
newTree.AddText(11, "x");
newTree.AddText(12, "x");
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 1);
Assert.Equal(0, entry.ReferenceFrameIndex);
},
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 2);
Assert.Equal(1, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Text(frame, "x", 10),
frame => AssertFrame.Text(frame, "x", 11));
}
[Fact]
public void RecognizesLeadingLoopBlockItemsBeingRemoved()
{
// Arrange
oldTree.AddText(2, "x");
oldTree.AddText(0, "x");
oldTree.AddText(1, "x");
oldTree.AddText(2, "x");
newTree.AddText(2, "x");
newTree.AddText(2, "x"); // Note that the '0' and '1' items are not present on this iteration
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 1),
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 1));
}
[Fact]
public void HandlesAdjacentItemsBeingRemovedAndInsertedAtOnce()
{
// Arrange
oldTree.AddText(0, "text");
newTree.AddText(1, "text");
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 0),
entry => AssertEdit(entry, RenderTreeEditType.PrependFrame, 0));
}
[Fact]
public void RecognizesTextUpdates()
{
// Arrange
oldTree.AddText(123, "old text 1");
oldTree.AddText(182, "old text 2");
newTree.AddText(123, "new text 1");
newTree.AddText(182, "new text 2");
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.UpdateText, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
},
entry =>
{
AssertEdit(entry, RenderTreeEditType.UpdateText, 1);
Assert.Equal(1, entry.ReferenceFrameIndex);
});
}
[Fact]
public void RecognizesElementNameChangesAtSameSequenceNumber()
{
// Note: It's not possible to trigger this scenario from a Razor component, because
// a given source sequence can only have a single fixed element name. We might later
// decide just to throw in this scenario, since it's unnecessary to support it.
// Arrange
oldTree.OpenElement(123, "old element");
oldTree.CloseElement();
newTree.OpenElement(123, "new element");
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 0),
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
});
}
[Fact]
public void RecognizesComponentTypeChangesAtSameSequenceNumber()
{
// Arrange
oldTree.OpenComponent<FakeComponent>(123);
oldTree.CloseComponent();
GetRenderedBatch(new RenderTreeBuilder(renderer), oldTree); // Assign initial IDs
newTree.OpenComponent<FakeComponent2>(123);
newTree.CloseComponent();
// Act
var renderBatch = GetRenderedBatch();
// Assert
Assert.Collection(renderBatch.DisposedComponentIDs,
disposedComponentId => Assert.Equal(0, disposedComponentId));
// Assert: First updated component is the root with one child being
// prepended, and its earlier incarnation being removed
Assert.Equal(2, renderBatch.UpdatedComponents.Count);
var updatedComponent1 = renderBatch.UpdatedComponents.Array[0];
Assert.Collection(updatedComponent1.Edits,
entry => AssertEdit(entry, RenderTreeEditType.RemoveFrame, 0),
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
Assert.IsType<FakeComponent2>(updatedComponent1.ReferenceFrames.Array[0].Component);
});
// Assert: Second updated component is the new FakeComponent2
var updatedComponent2 = renderBatch.UpdatedComponents.Array[1];
Assert.Collection(updatedComponent2.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
});
}
[Fact]
public void RecognizesAttributesAdded()
{
// Arrange
oldTree.OpenElement(0, "My element");
oldTree.AddAttribute(1, "existing", "existing value");
oldTree.CloseElement();
newTree.OpenElement(0, "My element");
newTree.AddAttribute(1, "existing", "existing value");
newTree.AddAttribute(2, "added", "added value");
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.SetAttribute, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Attribute(frame, "added", "added value"));
}
[Fact]
public void RecognizesAttributesRemoved()
{
// Arrange
oldTree.OpenElement(0, "My element");
oldTree.AddAttribute(1, "will be removed", "will be removed value");
oldTree.AddAttribute(2, "will survive", "surviving value");
oldTree.CloseElement();
newTree.OpenElement(0, "My element");
newTree.AddAttribute(2, "will survive", "surviving value");
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.RemoveAttribute, 0);
Assert.Equal("will be removed", entry.RemovedAttributeName);
});
}
[Fact]
public void RecognizesAttributeStringValuesChanged()
{
// Arrange
oldTree.OpenElement(0, "My element");
oldTree.AddAttribute(1, "will remain", "will remain value");
oldTree.AddAttribute(2, "will change", "will change value");
oldTree.CloseElement();
newTree.OpenElement(0, "My element");
newTree.AddAttribute(1, "will remain", "will remain value");
newTree.AddAttribute(2, "will change", "did change value");
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.SetAttribute, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Attribute(frame, "will change", "did change value"));
}
[Fact]
public void RecognizesAttributeEventHandlerValuesChanged()
{
// Arrange
UIEventHandler retainedHandler = _ => { };
UIEventHandler removedHandler = _ => { };
UIEventHandler addedHandler = _ => { };
oldTree.OpenElement(0, "My element");
oldTree.AddAttribute(1, "will remain", retainedHandler);
oldTree.AddAttribute(2, "will change", removedHandler);
oldTree.CloseElement();
newTree.OpenElement(0, "My element");
newTree.AddAttribute(1, "will remain", retainedHandler);
newTree.AddAttribute(2, "will change", addedHandler);
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.SetAttribute, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Attribute(frame, "will change", addedHandler));
}
[Fact]
public void RecognizesAttributeNamesChangedAtSameSourceSequence()
{
// Arrange
oldTree.OpenElement(0, "My element");
oldTree.AddAttribute(1, "oldname", "same value");
oldTree.CloseElement();
newTree.OpenElement(0, "My element");
newTree.AddAttribute(1, "newname", "same value");
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.RemoveAttribute, 0);
Assert.Equal("oldname", entry.RemovedAttributeName);
},
entry =>
{
AssertEdit(entry, RenderTreeEditType.SetAttribute, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Attribute(frame, "newname", "same value"));
}
[Fact]
public void DiffsElementsHierarchically()
{
// Arrange
oldTree.AddText(09, "unrelated");
oldTree.OpenElement(10, "root");
oldTree.OpenElement(11, "child");
oldTree.OpenElement(12, "grandchild");
oldTree.AddText(13, "grandchild old text");
oldTree.CloseElement();
oldTree.CloseElement();
oldTree.CloseElement();
newTree.AddText(09, "unrelated");
newTree.OpenElement(10, "root");
newTree.OpenElement(11, "child");
newTree.OpenElement(12, "grandchild");
newTree.AddText(13, "grandchild new text");
newTree.CloseElement();
newTree.CloseElement();
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.StepIn, 1),
entry => AssertEdit(entry, RenderTreeEditType.StepIn, 0),
entry => AssertEdit(entry, RenderTreeEditType.StepIn, 0),
entry =>
{
AssertEdit(entry, RenderTreeEditType.UpdateText, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
},
entry => AssertEdit(entry, RenderTreeEditType.StepOut, 0),
entry => AssertEdit(entry, RenderTreeEditType.StepOut, 0),
entry => AssertEdit(entry, RenderTreeEditType.StepOut, 0));
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Text(frame, "grandchild new text", 13));
}
[Fact]
public void SkipsUnmodifiedSubtrees()
{
// Arrange
oldTree.OpenElement(10, "root");
oldTree.AddText(11, "Text that will change");
oldTree.OpenElement(12, "Subtree that will not change");
oldTree.OpenElement(13, "Another");
oldTree.AddText(14, "Text that will not change");
oldTree.CloseElement();
oldTree.CloseElement();
oldTree.CloseElement();
newTree.OpenElement(10, "root");
newTree.AddText(11, "Text that has changed");
newTree.OpenElement(12, "Subtree that will not change");
newTree.OpenElement(13, "Another");
newTree.AddText(14, "Text that will not change");
newTree.CloseElement();
newTree.CloseElement();
newTree.CloseElement();
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry => AssertEdit(entry, RenderTreeEditType.StepIn, 0),
entry =>
{
AssertEdit(entry, RenderTreeEditType.UpdateText, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
},
entry => AssertEdit(entry, RenderTreeEditType.StepOut, 0));
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Text(frame, "Text that has changed", 11));
}
[Fact]
public void SkipsUnmodifiedTrailingSiblings()
{
// Arrange
oldTree.AddText(10, "text1");
oldTree.AddText(11, "text2");
oldTree.AddText(12, "text3");
oldTree.AddText(13, "text4");
newTree.AddText(10, "text1");
newTree.AddText(11, "text2modified");
newTree.AddText(12, "text3");
newTree.AddText(13, "text4");
// Act
var result = GetSingleUpdatedComponent();
// Assert
Assert.Collection(result.Edits,
entry =>
{
AssertEdit(entry, RenderTreeEditType.UpdateText, 1);
Assert.Equal(0, entry.ReferenceFrameIndex);
});
Assert.Collection(result.ReferenceFrames,
frame => AssertFrame.Text(frame, "text2modified", 11));
}
[Fact]
public void InstantiatesChildComponentsForInsertedFrames()
{
// Arrange
oldTree.AddText(10, "text1"); // 0: text1
oldTree.OpenElement(11, "container"); // 1: <container>
oldTree.CloseElement(); // </container>
newTree.AddText(10, "text1"); // 0: text1
newTree.OpenElement(11, "container"); // 1: <container>
newTree.OpenComponent<FakeComponent>(12); // 2: <FakeComponent>
newTree.CloseComponent(); // </FakeComponent>
newTree.OpenComponent<FakeComponent2>(13); // 3: <FakeComponent2>
newTree.CloseComponent(); // </FakeComponent2>
newTree.CloseElement(); // </container>
// Act
var renderBatch = GetRenderedBatch();
// Assert
Assert.Equal(3, renderBatch.UpdatedComponents.Count);
// First component is the root one
var firstComponentDiff = renderBatch.UpdatedComponents.Array[0];
Assert.Collection(firstComponentDiff.Edits,
entry => AssertEdit(entry, RenderTreeEditType.StepIn, 1),
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 0);
Assert.Equal(0, entry.ReferenceFrameIndex);
},
entry =>
{
AssertEdit(entry, RenderTreeEditType.PrependFrame, 1);
Assert.Equal(1, entry.ReferenceFrameIndex);
},
entry => AssertEdit(entry, RenderTreeEditType.StepOut, 0));
Assert.Collection(firstComponentDiff.ReferenceFrames,
frame => AssertFrame.ComponentWithInstance<FakeComponent>(frame, 0, 12),
frame => AssertFrame.ComponentWithInstance<FakeComponent2>(frame, 1, 13));
// Second in batch is the first child component
var secondComponentDiff = renderBatch.UpdatedComponents.Array[1];
Assert.Equal(0, secondComponentDiff.ComponentId);
Assert.Empty(secondComponentDiff.Edits); // Because FakeComponent produces no frames
Assert.Empty(secondComponentDiff.ReferenceFrames); // Because FakeComponent produces no frames
// Third in batch is the second child component
var thirdComponentDiff = renderBatch.UpdatedComponents.Array[2];
Assert.Equal(1, thirdComponentDiff.ComponentId);
Assert.Collection(thirdComponentDiff.Edits,
entry => AssertEdit(entry, RenderTreeEditType.PrependFrame, 0));
Assert.Collection(thirdComponentDiff.ReferenceFrames,
frame => AssertFrame.Text(frame, $"Hello from {nameof(FakeComponent2)}"));
}
[Fact]
public void SetsKnownPropertiesOnChildComponents()
{
// Arrange
var testObject = new object();
newTree.OpenComponent<FakeComponent>(0);
newTree.AddAttribute(1, nameof(FakeComponent.IntProperty), 123);
newTree.AddAttribute(2, nameof(FakeComponent.StringProperty), "some string");
newTree.AddAttribute(3, nameof(FakeComponent.ObjectProperty), testObject);
newTree.CloseComponent();
// Act
var renderBatch = GetRenderedBatch();
var componentInstance = newTree.GetFrames().First().Component as FakeComponent;
// Assert
Assert.Equal(2, renderBatch.UpdatedComponents.Count);
var rootComponentDiff = renderBatch.UpdatedComponents.Array[0];
AssertEdit(rootComponentDiff.Edits.Single(), RenderTreeEditType.PrependFrame, 0);
Assert.NotNull(componentInstance);
Assert.Equal(123, componentInstance.IntProperty);
Assert.Equal("some string", componentInstance.StringProperty);
Assert.Same(testObject, componentInstance.ObjectProperty);
}
[Fact]
public void ThrowsIfAssigningUnknownPropertiesToChildComponents()
{
// Arrange
var testObject = new object();
newTree.OpenComponent<FakeComponent>(0);
newTree.AddAttribute(1, "SomeUnknownProperty", 123);
newTree.CloseComponent();
// Act/Assert
var ex = Assert.Throws<InvalidOperationException>(() =>
{
diff.ApplyNewRenderTreeVersion(new RenderBatchBuilder(), 0, oldTree.GetFrames(), newTree.GetFrames());
});
Assert.Equal($"Component of type '{typeof(FakeComponent).FullName}' does not have a property matching the name 'SomeUnknownProperty'.", ex.Message);
}
[Fact]
public void ThrowsIfAssigningReadOnlyPropertiesToChildComponents()
{
// Arrange
var testObject = new object();
newTree.OpenComponent<FakeComponent>(0);
newTree.AddAttribute(1, nameof(FakeComponent.ReadonlyProperty), 123);
newTree.CloseComponent();
// Act/Assert
var ex = Assert.Throws<InvalidOperationException>(() =>
{
diff.ApplyNewRenderTreeVersion(new RenderBatchBuilder(), 0, oldTree.GetFrames(), newTree.GetFrames());
});
Assert.StartsWith($"Unable to set property '{nameof(FakeComponent.ReadonlyProperty)}' on " +
$"component of type '{typeof(FakeComponent).FullName}'.", ex.Message);
}
[Fact]
public void RetainsChildComponentsForExistingFrames()
{
// Arrange
oldTree.AddText(10, "text1"); // 0: text1
oldTree.OpenElement(11, "container"); // 1: <container>
oldTree.OpenComponent<FakeComponent>(12); // 2: <FakeComponent>
oldTree.CloseComponent(); // </FakeComponent>
oldTree.OpenComponent<FakeComponent2>(13); // 3: <FakeComponent2>
oldTree.CloseComponent(); // </FakeComponent2>
oldTree.CloseElement(); // </container>
newTree.AddText(10, "text1"); // 0: text1
newTree.OpenElement(11, "container"); // 1: <container>
newTree.OpenComponent<FakeComponent>(12); // 2: <FakeComponent>
newTree.CloseComponent(); // </FakeComponent>
newTree.OpenComponent<FakeComponent2>(13); // 3: <FakeComponent2>
newTree.CloseComponent(); // </FakeComponent2>
newTree.CloseElement(); // </container
diff.ApplyNewRenderTreeVersion(new RenderBatchBuilder(), 0, new RenderTreeBuilder(renderer).GetFrames(), oldTree.GetFrames());
var originalFakeComponentInstance = oldTree.GetFrames().Array[2].Component;
var originalFakeComponent2Instance = oldTree.GetFrames().Array[3].Component;
// Act
var result = GetSingleUpdatedComponent();
var newFrame1 = newTree.GetFrames().Array[2];
var newFrame2 = newTree.GetFrames().Array[3];
// Assert
Assert.Empty(result.Edits);
Assert.Equal(0, newFrame1.ComponentId);
Assert.Equal(1, newFrame2.ComponentId);
Assert.Same(originalFakeComponentInstance, newFrame1.Component);
Assert.Same(originalFakeComponent2Instance, newFrame2.Component);
}
[Fact]
public void UpdatesChangedPropertiesOnRetainedChildComponents()
{
// Arrange
var objectWillNotChange = new object();
oldTree.OpenComponent<FakeComponent>(12);
oldTree.AddAttribute(13, nameof(FakeComponent.StringProperty), "String will change");
oldTree.AddAttribute(14, nameof(FakeComponent.ObjectProperty), objectWillNotChange);
oldTree.CloseComponent();
newTree.OpenComponent<FakeComponent>(12);
newTree.AddAttribute(13, nameof(FakeComponent.StringProperty), "String did change");
newTree.AddAttribute(14, nameof(FakeComponent.ObjectProperty), objectWillNotChange);
newTree.CloseComponent();
diff.ApplyNewRenderTreeVersion(new RenderBatchBuilder(), 0, new RenderTreeBuilder(renderer).GetFrames(), oldTree.GetFrames());
var originalComponentInstance = (FakeComponent)oldTree.GetFrames().Array[0].Component;
originalComponentInstance.ObjectProperty = null; // So we can see it doesn't get reassigned
// Act
var renderBatch = GetRenderedBatch();
var newComponentInstance = (FakeComponent)oldTree.GetFrames().Array[0].Component;
// Assert
Assert.Equal(2, renderBatch.UpdatedComponents.Count);
Assert.Same(originalComponentInstance, newComponentInstance);
Assert.Equal("String did change", newComponentInstance.StringProperty);
Assert.Null(newComponentInstance.ObjectProperty); // To observe that the property wasn't even written, we nulled it out on the original
}
[Fact]
public void NotifiesIHandlePropertiesChangedBeforeFirstRender()
{
// Arrange
newTree.OpenComponent<HandlePropertiesChangedComponent>(0);
newTree.CloseComponent();
// Act
var batch = GetRenderedBatch();
var diffForChildComponent = batch.UpdatedComponents.Array[1];
// Assert
Assert.Collection(diffForChildComponent.ReferenceFrames,
frame => AssertFrame.Text(frame, "Notifications: 1", 0));
}
[Fact]
public void NotifiesIHandlePropertiesChangedWhenChanged()
{
// Arrange
var newTree1 = new RenderTreeBuilder(renderer);
var newTree2 = new RenderTreeBuilder(renderer);
oldTree.OpenComponent<HandlePropertiesChangedComponent>(0);
oldTree.AddAttribute(1, nameof(HandlePropertiesChangedComponent.IntProperty), 123);
oldTree.CloseComponent();
newTree1.OpenComponent<HandlePropertiesChangedComponent>(0);
newTree1.AddAttribute(1, nameof(HandlePropertiesChangedComponent.IntProperty), 123);
newTree1.CloseComponent();
newTree2.OpenComponent<HandlePropertiesChangedComponent>(0);
newTree2.AddAttribute(1, nameof(HandlePropertiesChangedComponent.IntProperty), 456);
newTree2.CloseComponent();
// Act/Assert 0: Initial render
var batch0 = GetRenderedBatch(new RenderTreeBuilder(renderer), oldTree);
var diffForChildComponent0 = batch0.UpdatedComponents.Array[1];
var childComponentFrame = batch0.UpdatedComponents.Array[0].ReferenceFrames.Array[0];
var childComponentInstance = (HandlePropertiesChangedComponent)childComponentFrame.Component;
Assert.Equal(1, childComponentInstance.NotificationsCount);
Assert.Collection(diffForChildComponent0.ReferenceFrames,
frame => AssertFrame.Text(frame, "Notifications: 1", 0));
// Act/Assert 1: If properties didn't change, we don't notify
GetRenderedBatch(oldTree, newTree1);
Assert.Equal(1, childComponentInstance.NotificationsCount);
// Act/Assert 2: If properties did change, we do notify
var batch2 = GetRenderedBatch(newTree1, newTree2);
var diffForChildComponent2 = batch2.UpdatedComponents.Array[1];
Assert.Equal(2, childComponentInstance.NotificationsCount);
Assert.Collection(diffForChildComponent2.ReferenceFrames,
frame => AssertFrame.Text(frame, "Notifications: 2", 0));
}
[Fact]
public void CallsDisposeOnlyOnRemovedChildComponents()
{
// Arrange
oldTree.OpenComponent<DisposableComponent>(10); // <DisposableComponent>
oldTree.CloseComponent(); // </DisposableComponent>
oldTree.OpenComponent<NonDisposableComponent>(20); // <NonDisposableComponent>
oldTree.CloseComponent(); // </NonDisposableComponent>
oldTree.OpenComponent<DisposableComponent>(30); // <DisposableComponent>
oldTree.CloseComponent(); // </DisposableComponent>
newTree.OpenComponent<DisposableComponent>(30); // <DisposableComponent>
newTree.CloseComponent(); // </DisposableComponent>
diff.ApplyNewRenderTreeVersion(new RenderBatchBuilder(), 0, new RenderTreeBuilder(renderer).GetFrames(), oldTree.GetFrames());
var disposableComponent1 = (DisposableComponent)oldTree.GetFrames().Array[0].Component;
var nonDisposableComponent = (NonDisposableComponent)oldTree.GetFrames().Array[1].Component;
var disposableComponent2 = (DisposableComponent)oldTree.GetFrames().Array[2].Component;
// Act
var renderedBatch = GetRenderedBatch();
// Assert: We track NonDisposableComponent was disposed even though it's not IDisposable
Assert.Equal(renderedBatch.DisposedComponentIDs, new[] { 0, 1 });
// Assert: We did call Dispose on the disposed DisposableComponent
Assert.Equal(1, disposableComponent1.DisposalCount);
// Assert: We didn't dispose the retained component
Assert.Equal(0, disposableComponent2.DisposalCount);
}
private RenderTreeDiff GetSingleUpdatedComponent()
{
var diffsInBatch = GetRenderedBatch().UpdatedComponents;
Assert.Equal(1, diffsInBatch.Count);
return diffsInBatch.Array[0];
}
private RenderBatch GetRenderedBatch()
=> GetRenderedBatch(oldTree, newTree);
private RenderBatch GetRenderedBatch(RenderTreeBuilder from, RenderTreeBuilder to)
{
var batchBuilder = new RenderBatchBuilder();
diff.ApplyNewRenderTreeVersion(batchBuilder, 0, from.GetFrames(), to.GetFrames());
return batchBuilder.ToBatch();
}
private class FakeRenderer : Renderer
{
internal protected override void UpdateDisplay(RenderBatch renderBatch)
{
}
}
private class FakeComponent : IComponent
{
public int IntProperty { get; set; }
public string StringProperty { get; set; }
public object ObjectProperty { get; set; }
public string ReadonlyProperty { get; private set; }
private string PrivateProperty { get; set; }
public void BuildRenderTree(RenderTreeBuilder builder)
{
}
}
private class FakeComponent2 : IComponent
{
public void BuildRenderTree(RenderTreeBuilder builder)
{
builder.AddText(100, $"Hello from {nameof(FakeComponent2)}");
}
}
private class HandlePropertiesChangedComponent : IComponent, IHandlePropertiesChanged
{
public int NotificationsCount { get; private set; }
public int IntProperty { get; set; }
public void BuildRenderTree(RenderTreeBuilder builder)
{
builder.AddText(0, $"Notifications: {NotificationsCount}");
}
public void OnPropertiesChanged()
{
NotificationsCount++;
}
}
private class DisposableComponent : IComponent, IDisposable
{
public int DisposalCount { get; private set; }
public void Dispose() => DisposalCount++;
public void BuildRenderTree(RenderTreeBuilder builder) { }
}
private class NonDisposableComponent : IComponent
{
public void BuildRenderTree(RenderTreeBuilder builder) { }
}
private static void AssertEdit(
RenderTreeEdit edit,
RenderTreeEditType type,
int siblingIndex)
{
Assert.Equal(type, edit.Type);
Assert.Equal(siblingIndex, edit.SiblingIndex);
}
}
}