public void Malformed_Weird() { var groupByDefault = new GroupByDefaultEnumerable <int, int, int, EmptyEnumerable <int>, EmptyEnumerator <int> >(); var groupBySpecific = new GroupBySpecificEnumerable <int, int, int, EmptyEnumerable <int>, EmptyEnumerator <int> >(); var lookupDefault = new LookupDefaultEnumerable <int, int>(); var lookupSpecific = new LookupSpecificEnumerable <int, int>(); var range = new RangeEnumerable(); var repeat = new RepeatEnumerable <int>(); var reverseRange = new ReverseRangeEnumerable(); var oneItemDefault = new OneItemDefaultEnumerable <int>(); var oneItemSpecific = new OneItemSpecificEnumerable <int>(); var oneItemDefaultOrdered = new OneItemDefaultOrderedEnumerable <int>(); var oneItemSpecificOrdered = new OneItemSpecificOrderedEnumerable <int>(); // groupByDefault { try { groupByDefault.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { groupByDefault.DefaultIfEmpty(groupByDefault.First()); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // groupBySpecific { try { groupBySpecific.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { groupBySpecific.DefaultIfEmpty(groupBySpecific.First()); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // lookupDefault { try { lookupDefault.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { lookupDefault.DefaultIfEmpty(lookupDefault.First()); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // lookupSpecific { try { lookupSpecific.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { lookupSpecific.DefaultIfEmpty(lookupDefault.First()); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // range { try { range.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { range.DefaultIfEmpty(4); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // repeat { try { repeat.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { repeat.DefaultIfEmpty(4); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // reverseRange { try { reverseRange.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { reverseRange.DefaultIfEmpty(4); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // oneItemDefault { try { oneItemDefault.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { oneItemDefault.DefaultIfEmpty(4); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // oneItemSpecific { try { oneItemSpecific.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { oneItemSpecific.DefaultIfEmpty(4); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // oneItemDefaultOrdered { try { oneItemDefaultOrdered.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { oneItemDefaultOrdered.DefaultIfEmpty(4); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } // oneItemSpecificOrdered { try { oneItemSpecificOrdered.DefaultIfEmpty(); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } try { oneItemSpecificOrdered.DefaultIfEmpty(4); Assert.Fail(); } catch (ArgumentException exc) { Assert.AreEqual("source", exc.ParamName); } } }