protected override Expression VisitMethodCall(MethodCallExpression node)
{
var instanceType = node.Object == null ? null : node.Object.Type;
var map = new[] { new { Param = instanceType, Arg = node.Object } }.ToList();
map.AddRange(node.Method.GetParameters()
.Zip(node.Arguments, (p, a) => new { Param = p.ParameterType, Arg = a }));
// for any local collection parameters in the method, make a
// replacement argument which will print its elements
var replacements = (map.Where(x => x.Param != null && x.Param.IsGenericType)
.Select(x => new {x, g = x.Param.GetGenericTypeDefinition()})
.Where(@t => @t.g == typeof (IEnumerable<>) || @t.g == typeof (List<>))
.Where(@t => @t.x.Arg.NodeType == ExpressionType.Constant)
.Select(@t => new {@t, elementType = @t.x.Param.GetGenericArguments().Single()})
.Select(
@t =>
new
{
@[email protected],
Replacement =
Expression.Constant("{" + string.Join("|", (IEnumerable) ((ConstantExpression) @[email protected]).Value) + "}")
})).ToList();
if (replacements.Any())
{
var args = map.Select(x => (from r in replacements
where r.Arg == x.Arg
select r.Replacement).SingleOrDefault() ?? x.Arg).ToList();
node = node.Update(args.First(), args.Skip(1));
}
return base.VisitMethodCall(node);
}
public void SingleElementIndexedSelector()
{
var source = new[]
{
new { name = "Prakash", custID = 98088 }
};
string[] expected = { "Prakash" };
Assert.Equal(expected, source.Select((e, index) => e.name));
}
public void SelectProperty()
{
var source = new[]{
new { name="Prakash", custID=98088 },
new { name="Bob", custID=29099 },
new { name="Chris", custID=39033 },
new { name=(string)null, custID=30349 },
new { name="Prakash", custID=39030 }
};
string[] expected = { "Prakash", "Bob", "Chris", null, "Prakash" };
Assert.Equal(expected, source.Select(e => e.name));
}
public void TryGetInstance_WithConcreteBclLists_ProducesLists()
{
var resolver = new ListTypeResolver();
var types = new[]
{
typeof (ArrayList),
typeof (List<>),
typeof (Collection<>)
};
foreach (var name in types.Select(t => t.FullName)) {
IList<object> list;
Assert.IsTrue(resolver.TryGetListInstance(name, out list));
Assert.NotNull(list);
}
}
public void SelectWhere_Array_ReturnsExpectedValues()
{
int[] source = new[] { 1, 2, 3, 4, 5 };
Func<int, bool> evenPredicate = (value) => value % 2 == 0;
Func<int, int> addSelector = (value) => value + 1;
IEnumerable<int> result = source.Select(addSelector).Where(evenPredicate);
Assert.Equal(3, result.Count());
Assert.Equal(2, result.ElementAt(0));
Assert.Equal(4, result.ElementAt(1));
Assert.Equal(6, result.ElementAt(2));
}
public void SelectPropertyUsingIndex()
{
var source = new[]{
new { name="Prakash", custID=98088 },
new { name="Bob", custID=29099 },
new { name="Chris", custID=39033 }
};
string[] expected = { "Prakash", null, null };
Assert.Equal(expected, source.Select((e, i) => i == 0 ? e.name : null));
}
public void Select_SourceIsArray_Count()
{
var source = new[] { 1, 2, 3, 4 };
Assert.Equal(source.Length, source.Select(i => i * 2).Count());
}
public void Select_ResetCalledOnEnumerator_ExceptionThrown()
{
int[] source = new[] { 1, 2, 3, 4, 5 };
Func<int, int> selector = i => i + 1;
var result = source.Select(selector);
var enumerator = result.GetEnumerator();
Assert.Throws<NotSupportedException>(() => enumerator.Reset());
}
public void Select_GetEnumeratorCalledTwice_DifferentInstancesReturned()
{
int[] source = new[] { 1, 2, 3, 4, 5 };
var query = source.Select(i => i + 1);
var enumerator1 = query.GetEnumerator();
var enumerator2 = query.GetEnumerator();
Assert.Same(query, enumerator1);
Assert.NotSame(enumerator1, enumerator2);
enumerator1.Dispose();
enumerator2.Dispose();
}
public void Select_ExceptionThrownFromSelector_IteratorCanBeUsedAfterExceptionIsCaught()
{
int[] source = new[] { 1, 2, 3, 4, 5 };
Func<int, int> selector = i =>
{
if (i == 1)
throw new InvalidOperationException();
return i + 1;
};
var result = source.Select(selector);
var enumerator = result.GetEnumerator();
Assert.Throws<InvalidOperationException>(() => enumerator.MoveNext());
enumerator.MoveNext();
Assert.Equal(3 /* 2 + 1 */, enumerator.Current);
}
public void Select_ExceptionThrownFromSelector_ExceptionPropagatedToTheCaller()
{
int[] source = new[] { 1, 2, 3, 4, 5 };
Func<int, int> selector = i => { throw new InvalidOperationException(); };
var result = source.Select(selector);
var enumerator = result.GetEnumerator();
Assert.Throws<InvalidOperationException>(() => enumerator.MoveNext());
}
public void SelectSelect_SourceIsAnArray_ReturnsExpectedValues()
{
Func<int, int> selector = i => i + 1;
int[] source = new[] { 1, 2, 3, 4, 5 };
IEnumerable<int> query = source.Select(selector).Select(selector);
int index = 0;
foreach (var item in query)
{
var expected = selector(selector(source[index]));
Assert.Equal(expected, item);
index++;
}
Assert.Equal(source.Length, index);
}
public void Select_SourceIsAnArray_CurrentIsDefaultOfTAfterEnumeration()
{
int[] source = new[] { 1 };
Func<int, int> selector = i => i + 1;
IEnumerable<int> query = source.Select(selector);
var enumerator = query.GetEnumerator();
while (enumerator.MoveNext()) ;
Assert.Equal(default(int), enumerator.Current);
}
public void SelectPropertyPassingIndexOnLast()
{
var source = new[]{
new { name="Prakash", custID=98088},
new { name="Bob", custID=29099 },
new { name="Chris", custID=39033 },
new { name="Robert", custID=39033 },
new { name="Allen", custID=39033 },
new { name="Chuck", custID=39033 }
};
string[] expected = { null, null, null, null, null, "Chuck" };
Assert.Equal(expected, source.Select((e, i) => i == 5 ? e.name : null));
}