391 lines
18 KiB
C#
391 lines
18 KiB
C#
// Copyright (c) .NET Foundation. All rights reserved.
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// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
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using Microsoft.AspNetCore.Blazor.Components;
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using Microsoft.AspNetCore.Blazor.RenderTree;
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using Microsoft.AspNetCore.Blazor.Test.Helpers;
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using System;
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using System.Linq;
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using Xunit;
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namespace Microsoft.AspNetCore.Blazor.Test
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{
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public class CascadingParameterTest
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{
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[Fact]
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public void PassesCascadingParametersToNestedComponents()
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{
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// Arrange
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var renderer = new TestRenderer();
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<string>>(0);
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builder.AddAttribute(1, "Value", "Hello");
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builder.AddAttribute(2, RenderTreeBuilder.ChildContent, new RenderFragment(childBuilder =>
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{
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childBuilder.OpenComponent<CascadingParameterConsumerComponent<string>>(0);
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childBuilder.AddAttribute(1, "RegularParameter", "Goodbye");
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childBuilder.CloseComponent();
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}));
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builder.CloseComponent();
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});
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// Act/Assert
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var componentId = renderer.AssignRootComponentId(component);
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component.TriggerRender();
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var batch = renderer.Batches.Single();
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var nestedComponent = FindComponent<CascadingParameterConsumerComponent<string>>(batch, out var nestedComponentId);
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var nestedComponentDiff = batch.DiffsByComponentId[nestedComponentId].Single();
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// The nested component was rendered with the correct parameters
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Assert.Collection(nestedComponentDiff.Edits,
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edit =>
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{
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Assert.Equal(RenderTreeEditType.PrependFrame, edit.Type);
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AssertFrame.Text(
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batch.ReferenceFrames[edit.ReferenceFrameIndex],
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"CascadingParameter=Hello; RegularParameter=Goodbye");
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});
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Assert.Equal(1, nestedComponent.NumRenders);
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}
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[Fact]
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public void RetainsCascadingParametersWhenUpdatingDirectParameters()
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{
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// Arrange
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var renderer = new TestRenderer();
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var regularParameterValue = "Initial value";
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<string>>(0);
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builder.AddAttribute(1, "Value", "Hello");
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builder.AddAttribute(2, RenderTreeBuilder.ChildContent, new RenderFragment(childBuilder =>
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{
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childBuilder.OpenComponent<CascadingParameterConsumerComponent<string>>(0);
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childBuilder.AddAttribute(1, "RegularParameter", regularParameterValue);
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childBuilder.CloseComponent();
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}));
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builder.CloseComponent();
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});
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// Act 1: Render in initial state
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var componentId = renderer.AssignRootComponentId(component);
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component.TriggerRender();
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// Capture the nested component so we can verify the update later
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var firstBatch = renderer.Batches.Single();
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var nestedComponent = FindComponent<CascadingParameterConsumerComponent<string>>(firstBatch, out var nestedComponentId);
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Assert.Equal(1, nestedComponent.NumRenders);
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// Act 2: Render again with updated regular parameter
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regularParameterValue = "Changed value";
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component.TriggerRender();
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// Assert
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Assert.Equal(2, renderer.Batches.Count);
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var secondBatch = renderer.Batches[1];
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var nestedComponentDiff = secondBatch.DiffsByComponentId[nestedComponentId].Single();
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// The nested component was rendered with the correct parameters
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Assert.Collection(nestedComponentDiff.Edits,
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edit =>
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{
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Assert.Equal(RenderTreeEditType.UpdateText, edit.Type);
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Assert.Equal(0, edit.ReferenceFrameIndex); // This is the only change
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AssertFrame.Text(secondBatch.ReferenceFrames[0], "CascadingParameter=Hello; RegularParameter=Changed value");
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});
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Assert.Equal(2, nestedComponent.NumRenders);
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}
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[Fact]
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public void NotifiesDescendantsOfUpdatedCascadingParameterValuesAndPreservesDirectParameters()
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{
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// Arrange
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var providedValue = "Initial value";
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var renderer = new TestRenderer();
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<string>>(0);
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builder.AddAttribute(1, "Value", providedValue);
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builder.AddAttribute(2, RenderTreeBuilder.ChildContent, new RenderFragment(childBuilder =>
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{
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childBuilder.OpenComponent<CascadingParameterConsumerComponent<string>>(0);
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childBuilder.AddAttribute(1, "RegularParameter", "Goodbye");
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childBuilder.CloseComponent();
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}));
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builder.CloseComponent();
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});
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// Act 1: Initial render; capture nested component ID
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var componentId = renderer.AssignRootComponentId(component);
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component.TriggerRender();
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var firstBatch = renderer.Batches.Single();
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var nestedComponent = FindComponent<CascadingParameterConsumerComponent<string>>(firstBatch, out var nestedComponentId);
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Assert.Equal(1, nestedComponent.NumRenders);
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// Act 2: Re-render CascadingValue with new value
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providedValue = "Updated value";
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component.TriggerRender();
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// Assert: We re-rendered CascadingParameterConsumerComponent
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Assert.Equal(2, renderer.Batches.Count);
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var secondBatch = renderer.Batches[1];
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var nestedComponentDiff = secondBatch.DiffsByComponentId[nestedComponentId].Single();
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// The nested component was rendered with the correct parameters
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Assert.Collection(nestedComponentDiff.Edits,
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edit =>
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{
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Assert.Equal(RenderTreeEditType.UpdateText, edit.Type);
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Assert.Equal(0, edit.ReferenceFrameIndex); // This is the only change
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AssertFrame.Text(secondBatch.ReferenceFrames[0], "CascadingParameter=Updated value; RegularParameter=Goodbye");
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});
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Assert.Equal(2, nestedComponent.NumRenders);
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}
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[Fact]
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public void DoesNotNotifyDescendantsIfCascadingParameterValuesAreImmutableAndUnchanged()
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{
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// Arrange
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var renderer = new TestRenderer();
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<string>>(0);
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builder.AddAttribute(1, "Value", "Unchanging value");
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builder.AddAttribute(2, RenderTreeBuilder.ChildContent, new RenderFragment(childBuilder =>
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{
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childBuilder.OpenComponent<CascadingParameterConsumerComponent<string>>(0);
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childBuilder.AddAttribute(1, "RegularParameter", "Goodbye");
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childBuilder.CloseComponent();
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}));
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builder.CloseComponent();
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});
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// Act 1: Initial render
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var componentId = renderer.AssignRootComponentId(component);
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component.TriggerRender();
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var firstBatch = renderer.Batches.Single();
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var nestedComponent = FindComponent<CascadingParameterConsumerComponent<string>>(firstBatch, out _);
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Assert.Equal(3, firstBatch.DiffsByComponentId.Count); // Root + CascadingValue + nested
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Assert.Equal(1, nestedComponent.NumRenders);
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// Act/Assert: Re-render the CascadingValue; observe nested component wasn't re-rendered
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component.TriggerRender();
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// Assert: We did not re-render CascadingParameterConsumerComponent
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Assert.Equal(2, renderer.Batches.Count);
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var secondBatch = renderer.Batches[1];
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Assert.Equal(2, secondBatch.DiffsByComponentId.Count); // Root + CascadingValue, but not nested one
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Assert.Equal(1, nestedComponent.NumRenders);
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}
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[Fact]
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public void StopsNotifyingDescendantsIfTheyAreRemoved()
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{
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// Arrange
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var providedValue = "Initial value";
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var displayNestedComponent = true;
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var renderer = new TestRenderer();
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<string>>(0);
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builder.AddAttribute(1, "Value", providedValue);
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builder.AddAttribute(2, RenderTreeBuilder.ChildContent, new RenderFragment(childBuilder =>
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{
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if (displayNestedComponent)
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{
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childBuilder.OpenComponent<CascadingParameterConsumerComponent<string>>(0);
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childBuilder.AddAttribute(1, "RegularParameter", "Goodbye");
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childBuilder.CloseComponent();
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}
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}));
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builder.CloseComponent();
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});
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// Act 1: Initial render; capture nested component ID
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var componentId = renderer.AssignRootComponentId(component);
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component.TriggerRender();
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var firstBatch = renderer.Batches.Single();
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var nestedComponent = FindComponent<CascadingParameterConsumerComponent<string>>(firstBatch, out var nestedComponentId);
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Assert.Equal(1, nestedComponent.NumSetParametersCalls);
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Assert.Equal(1, nestedComponent.NumRenders);
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// Act/Assert 2: Re-render the CascadingValue; observe nested component wasn't re-rendered
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providedValue = "Updated value";
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displayNestedComponent = false; // Remove the nested componet
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component.TriggerRender();
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// Assert: We did not render the nested component now it's been removed
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Assert.Equal(2, renderer.Batches.Count);
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var secondBatch = renderer.Batches[1];
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Assert.Equal(1, nestedComponent.NumRenders);
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Assert.Equal(2, secondBatch.DiffsByComponentId.Count); // Root + CascadingValue, but not nested one
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// We *did* send updated params during the first render where it was removed,
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// because the params are sent before the disposal logic runs. We could avoid
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// this by moving the notifications into the OnAfterRender phase, but then we'd
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// often render descendants twice (once because they are descendants and some
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// direct parameter might have changed, then once because a cascading parameter
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// changed). We can't have it both ways, so optimize for the case when the
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// nested component *hasn't* just been removed.
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Assert.Equal(2, nestedComponent.NumSetParametersCalls);
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// Act 3: However, after disposal, the subscription is removed, so we won't send
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// updated params on subsequent CascadingValue renders.
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providedValue = "Updated value 2";
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component.TriggerRender();
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Assert.Equal(2, nestedComponent.NumSetParametersCalls);
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}
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[Fact]
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public void DoesNotNotifyDescendantsOfUpdatedCascadingParameterValuesWhenFixed()
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{
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// Arrange
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var providedValue = "Initial value";
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var shouldIncludeChild = true;
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var renderer = new TestRenderer();
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<string>>(0);
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builder.AddAttribute(1, "Value", providedValue);
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builder.AddAttribute(2, "Fixed", true);
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builder.AddAttribute(3, RenderTreeBuilder.ChildContent, new RenderFragment(childBuilder =>
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{
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if (shouldIncludeChild)
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{
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childBuilder.OpenComponent<CascadingParameterConsumerComponent<string>>(0);
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childBuilder.AddAttribute(1, "RegularParameter", "Goodbye");
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childBuilder.CloseComponent();
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}
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}));
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builder.CloseComponent();
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});
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// Act 1: Initial render; capture nested component ID
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var componentId = renderer.AssignRootComponentId(component);
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component.TriggerRender();
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var firstBatch = renderer.Batches.Single();
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var nestedComponent = FindComponent<CascadingParameterConsumerComponent<string>>(firstBatch, out var nestedComponentId);
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Assert.Equal(1, nestedComponent.NumRenders);
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// Assert: Initial value is supplied to descendant
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var nestedComponentDiff = firstBatch.DiffsByComponentId[nestedComponentId].Single();
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Assert.Collection(nestedComponentDiff.Edits, edit =>
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{
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Assert.Equal(RenderTreeEditType.PrependFrame, edit.Type);
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AssertFrame.Text(
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firstBatch.ReferenceFrames[edit.ReferenceFrameIndex],
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"CascadingParameter=Initial value; RegularParameter=Goodbye");
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});
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// Act 2: Re-render CascadingValue with new value
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providedValue = "Updated value";
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component.TriggerRender();
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// Assert: We did not re-render the descendant
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Assert.Equal(2, renderer.Batches.Count);
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var secondBatch = renderer.Batches[1];
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Assert.Equal(2, secondBatch.DiffsByComponentId.Count); // Root + CascadingValue, but not nested one
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Assert.Equal(1, nestedComponent.NumSetParametersCalls);
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Assert.Equal(1, nestedComponent.NumRenders);
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// Act 3: Dispose
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shouldIncludeChild = false;
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component.TriggerRender();
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// Assert: Absence of an exception here implies we didn't cause a problem by
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// trying to remove a non-existent subscription
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}
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[Fact]
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public void CascadingValueThrowsIfFixedFlagChangesToTrue()
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{
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// Arrange
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var renderer = new TestRenderer();
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var isFixed = false;
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<object>>(0);
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builder.AddAttribute(1, "Fixed", isFixed);
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builder.AddAttribute(2, "Value", new object());
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builder.CloseComponent();
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});
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renderer.AssignRootComponentId(component);
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component.TriggerRender();
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// Act/Assert
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isFixed = true;
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var ex = Assert.Throws<InvalidOperationException>(() => component.TriggerRender());
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Assert.Equal("The value of Fixed cannot be changed dynamically.", ex.Message);
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}
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[Fact]
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public void CascadingValueThrowsIfFixedFlagChangesToFalse()
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{
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// Arrange
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var renderer = new TestRenderer();
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var isFixed = true;
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var component = new TestComponent(builder =>
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{
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builder.OpenComponent<CascadingValue<object>>(0);
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if (isFixed) // Showing also that "unset" is treated as "false"
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{
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builder.AddAttribute(1, "Fixed", true);
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}
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builder.AddAttribute(2, "Value", new object());
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builder.CloseComponent();
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});
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renderer.AssignRootComponentId(component);
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component.TriggerRender();
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// Act/Assert
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isFixed = false;
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var ex = Assert.Throws<InvalidOperationException>(() => component.TriggerRender());
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Assert.Equal("The value of Fixed cannot be changed dynamically.", ex.Message);
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}
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private static T FindComponent<T>(CapturedBatch batch, out int componentId)
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{
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var componentFrame = batch.ReferenceFrames.Single(
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frame => frame.FrameType == RenderTreeFrameType.Component
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&& frame.Component is T);
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componentId = componentFrame.ComponentId;
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return (T)componentFrame.Component;
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}
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class TestComponent : AutoRenderComponent
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{
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private readonly RenderFragment _renderFragment;
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public TestComponent(RenderFragment renderFragment)
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{
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_renderFragment = renderFragment;
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}
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protected override void BuildRenderTree(RenderTreeBuilder builder)
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=> _renderFragment(builder);
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}
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class CascadingParameterConsumerComponent<T> : AutoRenderComponent
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{
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public int NumSetParametersCalls { get; private set; }
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public int NumRenders { get; private set; }
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[CascadingParameter] T CascadingParameter { get; set; }
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[Parameter] string RegularParameter { get; set; }
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public override void SetParameters(ParameterCollection parameters)
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{
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NumSetParametersCalls++;
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base.SetParameters(parameters);
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}
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protected override void BuildRenderTree(RenderTreeBuilder builder)
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{
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NumRenders++;
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builder.AddContent(0, $"CascadingParameter={CascadingParameter}; RegularParameter={RegularParameter}");
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}
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}
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}
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}
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