public class ForthTests { [Fact] public void Parsing_and_numbers_numbers_just_get_pushed_onto_the_stack() { Assert.Equal("1 2 3 4 5", Forth.Evaluate(["1 2 3 4 5"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Parsing_and_numbers_pushes_negative_numbers_onto_the_stack() { Assert.Equal("-1 -2 -3 -4 -5", Forth.Evaluate(["-1 -2 -3 -4 -5"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Addition_can_add_two_numbers() { Assert.Equal("3", Forth.Evaluate(["1 2 +"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Addition_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["+"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Addition_errors_if_there_is_only_one_value_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["1 +"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Addition_more_than_two_values_on_the_stack() { Assert.Equal("1 5", Forth.Evaluate(["1 2 3 +"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Subtraction_can_subtract_two_numbers() { Assert.Equal("-1", Forth.Evaluate(["3 4 -"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Subtraction_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["-"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Subtraction_errors_if_there_is_only_one_value_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["1 -"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Subtraction_more_than_two_values_on_the_stack() { Assert.Equal("1 9", Forth.Evaluate(["1 12 3 -"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Multiplication_can_multiply_two_numbers() { Assert.Equal("8", Forth.Evaluate(["2 4 *"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Multiplication_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["*"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Multiplication_errors_if_there_is_only_one_value_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["1 *"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Multiplication_more_than_two_values_on_the_stack() { Assert.Equal("1 6", Forth.Evaluate(["1 2 3 *"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Division_can_divide_two_numbers() { Assert.Equal("4", Forth.Evaluate(["12 3 /"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Division_performs_integer_division() { Assert.Equal("2", Forth.Evaluate(["8 3 /"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Division_errors_if_dividing_by_zero() { Assert.Throws(() => Forth.Evaluate(["4 0 /"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Division_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["/"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Division_errors_if_there_is_only_one_value_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["1 /"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Division_more_than_two_values_on_the_stack() { Assert.Equal("1 4", Forth.Evaluate(["1 12 3 /"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Combined_arithmetic_addition_and_subtraction() { Assert.Equal("-1", Forth.Evaluate(["1 2 + 4 -"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Combined_arithmetic_multiplication_and_division() { Assert.Equal("2", Forth.Evaluate(["2 4 * 3 /"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Combined_arithmetic_multiplication_and_addition() { Assert.Equal("13", Forth.Evaluate(["1 3 4 * +"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Combined_arithmetic_addition_and_multiplication() { Assert.Equal("7", Forth.Evaluate(["1 3 4 + *"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Dup_copies_a_value_on_the_stack() { Assert.Equal("1 1", Forth.Evaluate(["1 dup"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Dup_copies_the_top_value_on_the_stack() { Assert.Equal("1 2 2", Forth.Evaluate(["1 2 dup"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Dup_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["dup"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Drop_removes_the_top_value_on_the_stack_if_it_is_the_only_one() { Assert.Equal("", Forth.Evaluate(["1 drop"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Drop_removes_the_top_value_on_the_stack_if_it_is_not_the_only_one() { Assert.Equal("1", Forth.Evaluate(["1 2 drop"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Drop_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["drop"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Swap_swaps_the_top_two_values_on_the_stack_if_they_are_the_only_ones() { Assert.Equal("2 1", Forth.Evaluate(["1 2 swap"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Swap_swaps_the_top_two_values_on_the_stack_if_they_are_not_the_only_ones() { Assert.Equal("1 3 2", Forth.Evaluate(["1 2 3 swap"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Swap_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["swap"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Swap_errors_if_there_is_only_one_value_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["1 swap"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Over_copies_the_second_element_if_there_are_only_two() { Assert.Equal("1 2 1", Forth.Evaluate(["1 2 over"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Over_copies_the_second_element_if_there_are_more_than_two() { Assert.Equal("1 2 3 2", Forth.Evaluate(["1 2 3 over"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Over_errors_if_there_is_nothing_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["over"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Over_errors_if_there_is_only_one_value_on_the_stack() { Assert.Throws(() => Forth.Evaluate(["1 over"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_can_consist_of_built_in_words() { Assert.Equal("1 1 1", Forth.Evaluate([": dup-twice dup dup ;", "1 dup-twice"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_execute_in_the_right_order() { Assert.Equal("1 2 3", Forth.Evaluate([": countup 1 2 3 ;", "countup"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_can_override_other_user_defined_words() { Assert.Equal("1 1 1", Forth.Evaluate([": foo dup ;", ": foo dup dup ;", "1 foo"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_can_override_built_in_words() { Assert.Equal("1 1", Forth.Evaluate([": swap dup ;", "1 swap"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_can_override_built_in_operators() { Assert.Equal("12", Forth.Evaluate([": + * ;", "3 4 +"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_can_use_different_words_with_the_same_name() { Assert.Equal("5 6", Forth.Evaluate([": foo 5 ;", ": bar foo ;", ": foo 6 ;", "bar foo"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_can_define_word_that_uses_word_with_the_same_name() { Assert.Equal("11", Forth.Evaluate([": foo 10 ;", ": foo foo 1 + ;", "foo"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_cannot_redefine_non_negative_numbers() { Assert.Throws(() => Forth.Evaluate([": 1 2 ;"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_cannot_redefine_negative_numbers() { Assert.Throws(() => Forth.Evaluate([": -1 2 ;"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_errors_if_executing_a_non_existent_word() { Assert.Throws(() => Forth.Evaluate(["foo"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void User_defined_words_only_defines_locally() { Assert.Equal("0", Forth.Evaluate([": + - ;", "1 1 +"])); Assert.Equal("2", Forth.Evaluate(["1 1 +"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Case_insensitivity_dup_is_case_insensitive() { Assert.Equal("1 1 1 1", Forth.Evaluate(["1 DUP Dup dup"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Case_insensitivity_drop_is_case_insensitive() { Assert.Equal("1", Forth.Evaluate(["1 2 3 4 DROP Drop drop"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Case_insensitivity_swap_is_case_insensitive() { Assert.Equal("2 3 4 1", Forth.Evaluate(["1 2 SWAP 3 Swap 4 swap"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Case_insensitivity_over_is_case_insensitive() { Assert.Equal("1 2 1 2 1", Forth.Evaluate(["1 2 OVER Over over"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Case_insensitivity_user_defined_words_are_case_insensitive() { Assert.Equal("1 1 1 1", Forth.Evaluate([": foo dup ;", "1 FOO Foo foo"])); } [Fact(Skip = "Remove this Skip property to run this test")] public void Case_insensitivity_definitions_are_case_insensitive() { Assert.Equal("1 1 1 1", Forth.Evaluate([": SWAP DUP Dup dup ;", "1 swap"])); } }