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POMoq an IQueryable that returns itself
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  1. POMoq an IQueryable that returns itself
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    copied!<p>I'm setting up a test using a mocked <code>IQueryable</code> (using Moq) that I want to return itself when <code>.Where()</code> is called on it:</p> <pre><code>[SetUp] public void Setup() { mockPocos = new Mock&lt;IQueryable&lt;Poco&gt;&gt;(); mockPocos.Setup(foo =&gt; foo.Where(It.IsAny&lt;Expression&lt;Func&lt;Poco, bool&gt;&gt;&gt;())) .Returns(mockPocos.Object); } </code></pre> <p>(This way, I can mock methods/properties like <code>.Count</code> and know that regardless of how many times the method being tested runs queries over the <code>IQueryable</code>, it will return values I can control.)</p> <p>This compiles, but when I run it, I get this exception:</p> <pre><code>Tests.PocoTest.TestPocoQueryable: SetUp : System.NotSupportedException : Expression references a method that does not belong to the mocked object: foo =&gt; foo.Where&lt;Poco&gt;(It.IsAny&lt;Expression`1&gt;()) </code></pre> <p>How can I get this to work?</p> <hr> <p>EDIT: In response to the comments, this is why I want to use Moq like this.</p> <p>In the method I'm testing, I have code like this:</p> <pre><code>public int[] MethodToTest(IQueryable&lt;Poco&gt; pocos, MockableDependency dependency) { var mostRecentUpdate = (from poco in pocos select poco.Date_Last_Updated).Max(); var recentPocos = pocos.Where(x =&gt; x.Date_Last_Updated.CompareTo(mostRecentUpdate) &gt;= 0); ///...snip... result[0] = SomePrivateCalculation(recentPocos.Count); result[1] = dependency.DoADifferentCalculation(recentPocos); } </code></pre> <p>I'm already mocking the <code>MockableDependency</code>, so I don't actually need to worry about what <code>Poco</code>s are in <code>pocos</code>. However, I would like to be able to control what the value of <code>recentPocos.Count</code> is, and I would like to be able to know that it will return the same value no matter how many queries are run over <code>pocos</code> before <code>.Count</code> is accessed.</p>
 

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