def test_return_in_the_middle(self, capsys):
"""
Test that we can return from a function in the middle of a loop.
It runs until 100, but will exit when n == 3, before printing n
"""
statement = [
"fun count(n) {",
" while (n < 100) {",
" if (n == 3) return n; // <--",
" print n;",
" n = n + 1;",
" }",
"}",
"",
"count(1);",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "1\n2\n"
def test_recursive_fibonacci(self, capsys):
"""
Example from crafting interpreters, a recursive Fibonacci function
"""
statement = [
"fun fib(n) {",
" if (n <= 1) return n;",
" return fib(n - 2) + fib(n - 1);",
"}",
"",
"for (var i = 0; i < 20; i = i + 1) {",
" print fib(i);",
"}",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
# We expect the first 20 numbers:
# fmt: off
fibonacci = [
0, 1, 1, 2, 3,
5, 8, 13, 21, 34,
55, 89, 144, 233, 377,
610, 987, 1597, 2584, 4181,
]
# fmt: on
expected_str_output = "\n".join([str(nr) for nr in fibonacci]) + "\n"
assert captured.out == expected_str_output
def test_empty_return(self, capsys):
"""
This test looks like test_return_in_the_middle, but instead or returning n, it
will return nothing.
"""
statement = [
"fun count(n) {",
" while (n < 100) {",
" if (n == 3) return; // <--",
" print n;",
" n = n + 1;",
" }",
"}",
"",
"print count(1);",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "1\n2\nnil\n"
def test_fibonacci_sequence(self, capsys):
""" Compute fibonacci numbers """
source = [
"var a = 0;",
"var b = 1;",
"",
"while (a < 10000) {",
" print a;",
" var temp = a;",
" a = b;",
" b = temp + b;",
"}",
]
source = "\n".join(source)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
# We expect the first 21 numbers:
# fmt: off
fibonacci = [
0, 1, 1, 2, 3,
5, 8, 13, 21, 34,
55, 89, 144, 233, 377,
610, 987, 1597, 2584, 4181,
6765,
]
# fmt: on
expected_str_output = "\n".join([str(nr) for nr in fibonacci]) + "\n"
assert captured.out == expected_str_output
def test_if_or(self, capsys):
statement = [
"var a = 4;",
"var b = 3;",
'if (a == 3 or b == 3) { print "or b == 3"; } ',
'if (a == 3 or b == 4) { print ""; } else { print "both false"; } ',
'if (a == 4 or b == 3) { print "or true"; } else { print ""; } ',
'if (a == 4 or b == 4) { print "only a true"; } else { print ""; } ',
'if (a == 4 and b == 3) { print "a and b"; } else { print ""; } ',
'if (a == 3 and b == 3) { print ""; } else { print "a != 3"; } ',
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == (
"or b == 3\n"
"both false\n"
"or true\n"
"only a true\n"
"a and b\n"
"a != 3\n"
)
def test_for_missing_increment(self, capsys):
""" Missing increment should still work """
source = [
"for(var a = 0; a <= 5;) {",
" print a;",
" a = a + 1;" "}",
]
source = "\n".join(source)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
expected_str_output = "\n".join([str(n) for n in range(6)]) + "\n"
assert captured.out == expected_str_output
# But the trailing ; must be present
source = source.replace("5;)", "5)")
yaplox = Yaplox()
yaplox.run(source)
assert yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert "Expect ';' after loop condition." in captured.err
def test_closures(self, capsys):
"""
Test closures, where a function in a function must have access to variables that
are created in the first function.
"""
statement = [
"fun makeCounter() {",
" var i = 0;",
" fun count() {",
" i = i + 1;",
" print i;",
" }",
"",
" return count;",
"}",
"",
"var counter = makeCounter();",
"counter(); // 1.",
"counter(); // 2.",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "1\n2\n"
def test_call_string(self, capsys):
"""
Try to call a string. This must fail cleanly
"""
source = '"ThisIsAstring"();'
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.err == "Can only call functions and classes. in line [line1]\n"
def test_empty_else(self, capsys):
statement = [
"var a = 4;",
"if (a == 4) {} else {}",
"if (a == 5) {} else {}",
"if (a) {} else {}",
"if (!a) {} else {}",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
def test_print_function(self, capsys):
""" Test printing a function, and test if an empty body works """
statement = [
"fun my_function() {}",
"",
"print my_function;",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "<fn my_function>\n"
def test_clock(self, capsys):
"""
Test the clock function, should return a time.
Since this will return the actual time, we just validate that it's an number
"""
source = "print clock();"
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
# Remove the newlines
time_float = float(captured.out)
assert isinstance(time_float, float)
def test_for(self, capsys):
source = [
"for(var a = 0; a <= 5; a = a + 1) {",
" print a;",
"}",
]
source = "\n".join(source)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
expected_str_output = "\n".join([str(n) for n in range(6)]) + "\n"
assert captured.out == expected_str_output
def test_no_arguments(self, capsys):
statement = [
"fun say_no_args() {",
' print "Hi, I have no arguments";',
"}",
"",
"say_no_args();",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "Hi, I have no arguments\n"
def test_return_nothing(self, capsys):
"""
Test a function that returns nothing
"""
statement = [
"fun return_nothing() { }",
"print return_nothing();",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "nil\n"
def test_no_arguments_still_arguments_given(self, capsys):
statement = [
"fun say_no_args() {",
' print "Hi, I have no arguments";',
"}",
"",
'say_no_args("But", "here", "We", "Are");',
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == ""
assert captured.err == "Expected 0 arguments but got 4. in line [line5]\n"
def test_say_hi(self, capsys):
""" "
The example function that is in chapter 10.4.1
"""
statement = [
"fun sayHi(first, last) {",
' print "Hi, " + first + " " + last + "!";',
"}",
"",
'sayHi("Dear", "Reader");',
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "Hi, Dear Reader!\n"
def test_arguments_but_none_given(self, capsys):
statement = [
"fun sayHi(first, last) {",
' print "Hi, " + first + " " + last + "!";',
"}",
"",
"// Prince doesn't have a last name...",
'sayHi("Prince");',
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == ""
assert captured.err == "Expected 2 arguments but got 1. in line [line6]\n"
def test_too_many_arguments_in_call(self, capsys):
arguments = ", ".join([f"arg_{n:03}" for n in range(256)])
statement = ["fun sayHi() {", ' print "Hi!";', "}" "", f"sayHi({arguments});"]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
# This should give a parse error
assert yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == ""
# This must give the error about too many arguments.
assert (
"[line 4] Error at 'arg_255' : Cannot have more than 255 arguments."
in captured.err
)
def test_simple_while(self, capsys):
source = [
"var a = 0;",
"",
"while (a < 10) {",
" print a;",
" a = a + 1;",
"}",
]
source = "\n".join(source)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
expected_str_output = "\n".join([str(n) for n in range(10)]) + "\n"
assert captured.out == expected_str_output
def test_if_else(self, capsys):
statement = [
"var a = 4;",
"if (a == 4) {",
' print "a == 4";',
"}",
"if (a != 5) {",
' print "a != 5";',
"} else {",
' print "a == 5";',
"}",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "a == 4\na != 5\n"
def test_recursion(self, capsys):
"""
Test that a function can all itself.
This code example is also from the crafting interpreters book
"""
statement = [
"fun count(n) {",
" if (n > 1) count(n - 1);",
" print n;",
"}",
"",
"count(3);",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "1\n2\n3\n"
def test_return(self, capsys):
"""
Test that a function can all itself.
This code example is also from the crafting interpreters book
"""
statement = [
"fun add(a, b) {",
" var result = (a - 1) + (b - 1);",
" return result + 2 ;",
"}",
"",
"print add(3, 5);",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "8\n"
def test_too_many_parameters_in_definition(self, capsys):
parameters = ", ".join([f"arg_{n:03}" for n in range(256)])
statement = [
f"fun sayHi({parameters}) {{",
' print "Hi!";',
"}",
]
source = "\n".join(statement)
yaplox = Yaplox()
yaplox.run(source)
# This should give a parse error
assert yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == ""
# This must give the error about too many parameters.
assert (
"[line 1] Error at 'arg_255' : Cannot have more than 255 parameters."
in captured.err
)
def test_missing_paren(self, capsys):
""" Test missing ( and ) in if statements"""
complete_statement = [
"var a = 4;" "if (a == 4) {",
' print "Four!";',
"}",
]
source = "\n".join(complete_statement)
left_missing = source.replace("(", "")
right_missing = source.replace(")", "")
# Test a valid statement
yaplox = Yaplox()
yaplox.run(source)
assert not yaplox.had_error
assert not yaplox.had_runtime_error
captured = capsys.readouterr()
assert captured.out == "Four!\n"
# Test with left ( missing error, on a clean yaplox instance
yaplox = Yaplox()
yaplox.run(left_missing)
assert yaplox.had_error
captured = capsys.readouterr()
assert "Expect '(' after 'if'." in captured.err
# Test with right ) missing error, on a clean yaplox instance
yaplox = Yaplox()
yaplox.run(right_missing)
assert yaplox.had_error
captured = capsys.readouterr()
assert "Expect ')' after if condition." in captured.err