hy/tests/macros/test_macro_processor.py

# Copyright 2017 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
from hy.errors import HyMacroExpansionError

from hy.compiler import HyASTCompiler


@macro("test")
def tmac(*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"""
    try:
        macroexpand(tokenize('(defn)')[0], HyASTCompiler(__name__))
        assert False
    except HyMacroExpansionError as e:
        assert "_hy_anon_fn_" not in str(e)
        assert "TypeError" not in str(e)