aspnetcore/test/Microsoft.Blazor.Test/RenderTreeDiffTest.cs

534 lines
21 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.Blazor.Components;
using Microsoft.Blazor.Rendering;
using Microsoft.Blazor.RenderTree;
using System;
using System.Collections.Generic;
using System.Linq;
using Xunit;
namespace Microsoft.Blazor.Test
{
public class RenderTreeDiffTest
{
[Theory]
[MemberData(nameof(RecognizesEquivalentNodesAsSameCases))]
public void RecognizesEquivalentNodesAsSame(Action<RenderTreeBuilder> appendAction)
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
appendAction(oldTree);
appendAction(newTree);
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
public static IEnumerable<object[]> RecognizesEquivalentNodesAsSameCases()
=> 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.AddComponent<FakeComponent>(0)
}.Select(x => new object[] { x });
[Fact]
public void RecognizesNewItemsBeingInserted()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddText(0, "text0");
oldTree.AddText(2, "text2");
newTree.AddText(0, "text0");
newTree.AddText(1, "text1");
newTree.AddText(2, "text2");
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(1, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesOldItemsBeingRemoved()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddText(0, "text0");
oldTree.AddText(1, "text1");
oldTree.AddText(2, "text2");
newTree.AddText(0, "text0");
newTree.AddText(2, "text2");
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesTrailingSequenceWithinLoopBlockBeingRemoved()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesTrailingSequenceWithinLoopBlockBeingAppended()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddText(0, "x"); // Loop start
oldTree.AddText(0, "x"); // Loop start
newTree.AddText(0, "x"); // Loop start
newTree.AddText(1, "x"); // Will be added
newTree.AddText(2, "x"); // Will be added
newTree.AddText(0, "x"); // Loop start
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(1, entry.NewTreeIndex);
},
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(2, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesTrailingLoopBlockBeingRemoved()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type));
}
[Fact]
public void RecognizesTrailingLoopBlockBeingAdded()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddText(0, "x");
oldTree.AddText(1, "x");
newTree.AddText(0, "x");
newTree.AddText(1, "x");
newTree.AddText(0, "x"); // Will be added
newTree.AddText(1, "x"); // Will be added
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(2, entry.NewTreeIndex);
},
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(3, entry.NewTreeIndex);
});
}
[Fact]
public void RecognizesLeadingLoopBlockItemsBeingAdded()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddText(2, "x");
oldTree.AddText(2, "x"); // Note that the '0' and '1' items are not present on this iteration
newTree.AddText(2, "x");
newTree.AddText(0, "x");
newTree.AddText(1, "x");
newTree.AddText(2, "x");
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(1, entry.NewTreeIndex);
},
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(2, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesLeadingLoopBlockItemsBeingRemoved()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void HandlesAdjacentItemsBeingRemovedAndInsertedAtOnce()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddText(0, "text");
newTree.AddText(1, "text");
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type),
entry => Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type));
}
[Fact]
public void RecognizesTextUpdates()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddText(123, "old text");
newTree.AddText(123, "new text");
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.UpdateText, entry.Type);
Assert.Equal(0, entry.NewTreeIndex);
});
}
[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
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.OpenElement(123, "old element");
oldTree.CloseElement();
newTree.OpenElement(123, "new element");
newTree.CloseElement();
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(0, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type));
}
[Fact]
public void RecognizesComponentTypeChangesAtSameSequenceNumber()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
oldTree.AddComponent<FakeComponent>(123);
newTree.AddComponent<FakeComponent2>(123);
// Act
var result = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.PrependNode, entry.Type);
Assert.Equal(0, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.RemoveNode, entry.Type));
}
[Fact]
public void RecognizesAttributesAdded()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.SetAttribute, entry.Type);
Assert.Equal(2, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesAttributesRemoved()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.RemoveAttribute, entry.Type);
Assert.Equal("will be removed", entry.RemovedAttributeName);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesAttributeStringValuesChanged()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.SetAttribute, entry.Type);
Assert.Equal(2, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesAttributeEventHandlerValuesChanged()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.SetAttribute, entry.Type);
Assert.Equal(2, entry.NewTreeIndex);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
[Fact]
public void RecognizesAttributeNamesChangedAtSameSourceSequence()
{
// Arrange
var oldTree = new RenderTreeBuilder(new FakeRenderer());
var newTree = new RenderTreeBuilder(new FakeRenderer());
var diff = new RenderTreeDiff();
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 = diff.ComputeDifference(oldTree.GetNodes(), newTree.GetNodes());
// Assert
Assert.Collection(result,
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.SetAttribute, entry.Type);
Assert.Equal(1, entry.NewTreeIndex);
},
entry =>
{
Assert.Equal(RenderTreeDiffEntryType.RemoveAttribute, entry.Type);
Assert.Equal("oldname", entry.RemovedAttributeName);
},
entry => Assert.Equal(RenderTreeDiffEntryType.Continue, entry.Type));
}
private class FakeRenderer : Renderer
{
internal protected override void UpdateDisplay(int componentId, ArraySegment<RenderTreeNode> renderTree)
=> throw new NotImplementedException();
}
private class FakeComponent : IComponent
{
public void BuildRenderTree(RenderTreeBuilder builder)
=> throw new NotImplementedException();
}
private class FakeComponent2 : IComponent
{
public void BuildRenderTree(RenderTreeBuilder builder)
=> throw new NotImplementedException();
}
}
}