Imports System Imports System.Collections.Generic Imports Xunit Public Class ListOpsTests Public Sub Append_entries_to_a_list_and_return_the_new_list_empty_lists() Dim list1 = New List(Of Integer)() Dim list2 = New List(Of Integer)() Assert.Empty(Append(list1, list2)) End Sub Public Sub Append_entries_to_a_list_and_return_the_new_list_list_to_empty_list() Dim list1 = New List(Of Integer)() Dim list2 = New List(Of Integer) From { 1, 2, 3, 4 } Dim expected = New List(Of Integer) From { 1, 2, 3, 4 } Assert.Equal(expected, Append(list1, list2)) End Sub Public Sub Append_entries_to_a_list_and_return_the_new_list_empty_list_to_list() Dim list1 = New List(Of Integer) From { 1, 2, 3, 4 } Dim list2 = New List(Of Integer)() Dim expected = New List(Of Integer) From { 1, 2, 3, 4 } Assert.Equal(expected, Append(list1, list2)) End Sub Public Sub Append_entries_to_a_list_and_return_the_new_list_non_empty_lists() Dim list1 = New List(Of Integer) From { 1, 2 } Dim list2 = New List(Of Integer) From { 2, 3, 4, 5 } Dim expected = New List(Of Integer) From { 1, 2, 2, 3, 4, 5 } Assert.Equal(expected, Append(list1, list2)) End Sub Public Sub Concatenate_a_list_of_lists_empty_list() Dim lists = New List(Of List(Of Integer))() Assert.Empty(Concat(lists)) End Sub Public Sub Concatenate_a_list_of_lists_list_of_lists() Dim lists = New List(Of List(Of Integer)) From { New List(Of Integer) From { 1, 2 }, New List(Of Integer) From { 3 }, New List(Of Integer)(), New List(Of Integer) From { 4, 5, 6 } } Dim expected = New List(Of Integer) From { 1, 2, 3, 4, 5, 6 } Assert.Equal(expected, Concat(lists)) End Sub Public Sub Concatenate_a_list_of_lists_list_of_nested_lists() Dim lists = New List(Of List(Of List(Of Integer))) From { New List(Of List(Of Integer)) From { New List(Of Integer) From { 1 }, New List(Of Integer) From { 2 } }, New List(Of List(Of Integer)) From { New List(Of Integer) From { 3 } }, New List(Of List(Of Integer)) From { New List(Of Integer)() }, New List(Of List(Of Integer)) From { New List(Of Integer) From { 4, 5, 6 } } } Dim expected = New List(Of List(Of Integer)) From { New List(Of Integer) From { 1 }, New List(Of Integer) From { 2 }, New List(Of Integer) From { 3 }, New List(Of Integer)(), New List(Of Integer) From { 4, 5, 6 } } Assert.Equal(expected, Concat(lists)) End Sub Public Sub Filter_list_returning_only_values_that_satisfy_the_filter_function_empty_list() Dim list = New List(Of Integer)() Dim [function] = New Func(Of Integer, Boolean)(Function(x) x Mod 2 = 1) Assert.Empty(Filter(list, [function])) End Sub Public Sub Filter_list_returning_only_values_that_satisfy_the_filter_function_non_empty_list() Dim list = New List(Of Integer) From { 1, 2, 3, 5 } Dim [function] = New Func(Of Integer, Boolean)(Function(x) x Mod 2 = 1) Dim expected = New List(Of Integer) From { 1, 3, 5 } Assert.Equal(expected, Filter(list, [function])) End Sub Public Sub Returns_the_length_of_a_list_empty_list() Dim list = New List(Of Integer)() Assert.Equal(0, Length(list)) End Sub Public Sub Returns_the_length_of_a_list_non_empty_list() Dim list = New List(Of Integer) From { 1, 2, 3, 4 } Assert.Equal(4, Length(list)) End Sub Public Sub Return_a_list_of_elements_whose_values_equal_the_list_value_transformed_by_the_mapping_function_empty_list() Dim list = New List(Of Integer)() Dim [function] = New Func(Of Integer, Integer)(Function(x) x + 1) Assert.Empty(Map(list, [function])) End Sub Public Sub Return_a_list_of_elements_whose_values_equal_the_list_value_transformed_by_the_mapping_function_non_empty_list() Dim list = New List(Of Integer) From { 1, 3, 5, 7 } Dim [function] = New Func(Of Integer, Integer)(Function(x) x + 1) Dim expected = New List(Of Integer) From { 2, 4, 6, 8 } Assert.Equal(expected, Map(list, [function])) End Sub Public Sub Folds_reduces_the_given_list_from_the_left_with_a_function_direction_dependent_function_applied_to_non_empty_list() Dim list = New List(Of Integer) From { 2, 5 } Dim initial = 5 Dim [function] = New Func(Of Integer, Integer, Integer)(Function(x, y) x / y) Assert.Equal(0, Foldl(list, initial, [function])) End Sub Public Sub Folds_reduces_the_given_list_from_the_left_with_a_function_empty_list() Dim list = New List(Of Integer)() Dim initial = 2 Dim [function] = New Func(Of Integer, Integer, Integer)(Function(acc, el) el * acc) Assert.Equal(2, Foldl(list, initial, [function])) End Sub Public Sub Folds_reduces_the_given_list_from_the_left_with_a_function_direction_independent_function_applied_to_non_empty_list() Dim list = New List(Of Integer) From { 1, 2, 3, 4 } Dim initial = 5 Dim [function] = New Func(Of Integer, Integer, Integer)(Function(acc, el) el + acc) Assert.Equal(15, Foldl(list, initial, [function])) End Sub Public Sub Folds_reduces_the_given_list_from_the_right_with_a_function_direction_dependent_function_applied_to_non_empty_list() Dim list = New List(Of Integer) From { 2, 5 } Dim initial = 5 Dim [function] = New Func(Of Integer, Integer, Integer)(Function(x, y) x / y) Assert.Equal(2, Foldr(list, initial, [function])) End Sub Public Sub Folds_reduces_the_given_list_from_the_right_with_a_function_empty_list() Dim list = New List(Of Integer)() Dim initial = 2 Dim [function] = New Func(Of Integer, Integer, Integer)(Function(acc, el) el * acc) Assert.Equal(2, Foldr(list, initial, [function])) End Sub Public Sub Folds_reduces_the_given_list_from_the_right_with_a_function_direction_independent_function_applied_to_non_empty_list() Dim list = New List(Of Integer) From { 1, 2, 3, 4 } Dim initial = 5 Dim [function] = New Func(Of Integer, Integer, Integer)(Function(acc, el) el + acc) Assert.Equal(15, Foldr(list, initial, [function])) End Sub Public Sub Reverse_the_elements_of_the_list_empty_list() Dim list = New List(Of Integer)() Assert.Empty(Reverse(list)) End Sub Public Sub Reverse_the_elements_of_the_list_non_empty_list() Dim list = New List(Of Integer) From { 1, 3, 5, 7 } Dim expected = New List(Of Integer) From { 7, 5, 3, 1 } Assert.Equal(expected, Reverse(list)) End Sub Public Sub Reverse_the_elements_of_the_list_list_of_lists_is_not_flattened() Dim list = New List(Of List(Of Integer)) From { New List(Of Integer) From { 1, 2 }, New List(Of Integer) From { 3 }, New List(Of Integer)(), New List(Of Integer) From { 4, 5, 6 } } Dim expected = New List(Of List(Of Integer)) From { New List(Of Integer) From { 4, 5, 6 }, New List(Of Integer)(), New List(Of Integer) From { 3 }, New List(Of Integer) From { 1, 2 } } Assert.Equal(expected, Reverse(list)) End Sub End Class