hy/tests/macros/test_macro_processor.py

# Copyright 2018 the authors.
# This file is part of Hy, which is free software licensed under the Expat
# license. See the LICENSE.

from hy.macros import macro, macroexpand
from hy.lex import tokenize

from hy.models import HyString, HyList, HySymbol, HyExpression, HyFloat
from hy.errors import HyMacroExpansionError

from hy.compiler import HyASTCompiler

import pytest


@macro("test")
def tmac(ETname, *tree):
    """ Turn an expression into a list """
    return HyList(tree)


def test_preprocessor_simple():
    """ Test basic macro expansion """
    obj = macroexpand(tokenize('(test "one" "two")')[0],
                      HyASTCompiler(__name__))
    assert obj == HyList(["one", "two"])
    assert type(obj) == HyList


def test_preprocessor_expression():
    """ Test that macro expansion doesn't recurse"""
    obj = macroexpand(tokenize('(test (test "one" "two"))')[0],
                      HyASTCompiler(__name__))

    assert type(obj) == HyList
    assert type(obj[0]) == HyExpression

    assert obj[0] == HyExpression([HySymbol("test"),
                                   HyString("one"),
                                   HyString("two")])

    obj = HyList([HyString("one"), HyString("two")])
    obj = tokenize('(shill ["one" "two"])')[0][1]
    assert obj == macroexpand(obj, HyASTCompiler(""))


def test_preprocessor_exceptions():
    """ Test that macro expansion raises appropriate exceptions"""
    with pytest.raises(HyMacroExpansionError) as excinfo:
        macroexpand(tokenize('(defn)')[0], HyASTCompiler(__name__))
    assert "_hy_anon_fn_" not in excinfo.value.message
    assert "TypeError" not in excinfo.value.message


def test_macroexpand_nan():
   # https://github.com/hylang/hy/issues/1574
   import math
   NaN = float('nan')
   x = macroexpand(HyFloat(NaN), HyASTCompiler(__name__))
   assert type(x) is HyFloat
   assert math.isnan(x)