public void EqualsWhenValueIsNull()
{
ConstantExpression expr1 = new ConstantExpression(null);
ConstantExpression expr2 = new ConstantExpression(null);
ConstantExpression expr3 = new ConstantExpression("foo");
Assert.IsTrue(expr1.Equals(expr1));
Assert.IsTrue(expr1.Equals(expr2));
Assert.IsTrue(expr2.Equals(expr1));
Assert.AreEqual(expr1.GetHashCode(), expr2.GetHashCode());
Assert.IsFalse(expr1.Equals(expr3));
Assert.IsFalse(expr3.Equals(expr1));
}
public void Equals()
{
ConstantExpression expr1 = new ConstantExpression(123);
ConstantExpression expr2 = new ConstantExpression(124);
ConstantExpression expr3 = new ConstantExpression(123);
Assert.IsTrue(expr1.Equals(expr1));
Assert.IsTrue(expr1.Equals(expr3));
Assert.IsTrue(expr3.Equals(expr1));
Assert.AreEqual(expr1.GetHashCode(), expr3.GetHashCode());
Assert.IsFalse(expr1.Equals(123));
Assert.IsFalse(expr1.Equals(expr2));
Assert.IsFalse(expr2.Equals(expr1));
Assert.IsFalse(expr1.Equals(null));
}
public int GetHashCode(Expression x)
{
LambdaExpression lambdaExpressionX = x as LambdaExpression;
if (lambdaExpressionX != null)
{
return(XorHashCodes(lambdaExpressionX.Parameters) ^
GetHashCode(lambdaExpressionX.Body));
}
BinaryExpression binaryExpressionX = x as BinaryExpression;
if (binaryExpressionX != null)
{
int methodHashCode = binaryExpressionX.Method != null?binaryExpressionX.Method.GetHashCode() : binaryExpressionX.NodeType.GetHashCode();
return(methodHashCode ^
GetHashCode(binaryExpressionX.Left) ^
GetHashCode(binaryExpressionX.Right));
}
UnaryExpression unaryExpressionX = x as UnaryExpression;
if (unaryExpressionX != null)
{
int methodHashCode = unaryExpressionX.Method != null?unaryExpressionX.Method.GetHashCode() : unaryExpressionX.NodeType.GetHashCode();
return(methodHashCode ^
GetHashCode(unaryExpressionX.Operand));
}
MethodCallExpression methodCallExpressionX = x as MethodCallExpression;
if (methodCallExpressionX != null)
{
return(XorHashCodes(methodCallExpressionX.Arguments) ^
methodCallExpressionX.Method.GetHashCode() ^
GetHashCode(methodCallExpressionX.Object));
}
ConditionalExpression conditionalExpressionX = x as ConditionalExpression;
if (conditionalExpressionX != null)
{
return
(GetHashCode(conditionalExpressionX.Test) ^
GetHashCode(conditionalExpressionX.IfTrue) ^
GetHashCode(conditionalExpressionX.IfFalse));
}
InvocationExpression invocationExpressionX = x as InvocationExpression;
if (invocationExpressionX != null)
{
return
(XorHashCodes(invocationExpressionX.Arguments) ^
GetHashCode(invocationExpressionX.Expression));
}
MemberExpression memberExpressionX = x as MemberExpression;
if (memberExpressionX != null)
{
return
(memberExpressionX.Member.GetHashCode() ^
GetHashCode(memberExpressionX.Expression));
}
ConstantExpression constantExpressionX = x as ConstantExpression;
if (constantExpressionX != null)
{
int valueHash = constantExpressionX.Value != null?constantExpressionX.Value.GetHashCode() : constantExpressionX.GetHashCode();
return(valueHash);
}
NewExpression newExpressionX = x as NewExpression;
if (newExpressionX != null)
{
return
(XorHashCodes(newExpressionX.Arguments) ^
newExpressionX.Constructor.GetHashCode());
}
return(0);
}
