File: DotNetObjectReferenceTest.cs
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Project: src\src\JSInterop\Microsoft.JSInterop\test\Microsoft.JSInterop.Tests.csproj (Microsoft.JSInterop.Tests)
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
namespace Microsoft.JSInterop;
 
public class DotNetObjectReferenceTest
{
    [Fact]
    public void CanAccessValue()
    {
        var obj = new object();
        Assert.Same(obj, DotNetObjectReference.Create(obj).Value);
    }
 
    [Fact]
    public void TrackObjectReference_AssignsObjectId()
    {
        // Arrange
        var jsRuntime = new TestJSRuntime();
        var objRef = DotNetObjectReference.Create(new object());
 
        // Act
        var objectId = jsRuntime.TrackObjectReference(objRef);
 
        // Act
        Assert.Equal(objectId, objRef.ObjectId);
        Assert.Equal(1, objRef.ObjectId);
    }
 
    [Fact]
    public void TrackObjectReference_AllowsMultipleCallsUsingTheSameJSRuntime()
    {
        // Arrange
        var jsRuntime = new TestJSRuntime();
        var objRef = DotNetObjectReference.Create(new object());
 
        // Act
        var objectId1 = jsRuntime.TrackObjectReference(objRef);
        var objectId2 = jsRuntime.TrackObjectReference(objRef);
 
        // Act
        Assert.Equal(objectId1, objectId2);
    }
 
    [Fact]
    public void TrackObjectReference_ThrowsIfDifferentJSRuntimeInstancesAreUsed()
    {
        // Arrange
        var objRef = DotNetObjectReference.Create("Hello world");
        var expected = $"{objRef.GetType().Name} is already being tracked by a different instance of {nameof(JSRuntime)}. A common cause is caching an instance of {nameof(DotNetObjectReference<string>)}" +
                $" globally. Consider creating instances of {nameof(DotNetObjectReference<string>)} at the JSInterop callsite.";
        var jsRuntime1 = new TestJSRuntime();
        var jsRuntime2 = new TestJSRuntime();
        jsRuntime1.TrackObjectReference(objRef);
 
        // Act
        var ex = Assert.Throws<InvalidOperationException>(() => jsRuntime2.TrackObjectReference(objRef));
 
        // Assert
        Assert.Equal(expected, ex.Message);
    }
 
    [Fact]
    public void Dispose_StopsTrackingObject()
    {
        // Arrange
        var objRef = DotNetObjectReference.Create("Hello world");
        var jsRuntime = new TestJSRuntime();
        jsRuntime.TrackObjectReference(objRef);
        var objectId = objRef.ObjectId;
        var expected = $"There is no tracked object with id '{objectId}'. Perhaps the DotNetObjectReference instance was already disposed.";
 
        // Act
        Assert.Same(objRef, jsRuntime.GetObjectReference(objectId));
        objRef.Dispose();
 
        // Assert
        Assert.True(objRef.Disposed);
        Assert.Throws<ArgumentException>(() => jsRuntime.GetObjectReference(objectId));
    }
 
    [Fact]
    public void DoubleDispose_Works()
    {
        // Arrange
        var objRef = DotNetObjectReference.Create("Hello world");
        var jsRuntime = new TestJSRuntime();
        jsRuntime.TrackObjectReference(objRef);
        var objectId = objRef.ObjectId;
 
        // Act
        Assert.Same(objRef, jsRuntime.GetObjectReference(objectId));
        objRef.Dispose();
 
        // Assert
        objRef.Dispose();
        // If we got this far, this did not throw.
    }
}