# testing.py
from contextlib import contextmanager
import typing
from .core import (
ParserElement,
ParseException,
Keyword,
__diag__,
__compat__,
)
class pyparsing_test:
"""
namespace class for classes useful in writing unit tests
"""
class reset_pyparsing_context:
"""
Context manager to be used when writing unit tests that modify pyparsing config values:
- packrat parsing
- bounded recursion parsing
- default whitespace characters.
- default keyword characters
- literal string auto-conversion class
- __diag__ settings
Example::
with reset_pyparsing_context():
# test that literals used to construct a grammar are automatically suppressed
ParserElement.inlineLiteralsUsing(Suppress)
term = Word(alphas) | Word(nums)
group = Group('(' + term[...] + ')')
# assert that the '()' characters are not included in the parsed tokens
self.assertParseAndCheckList(group, "(abc 123 def)", ['abc', '123', 'def'])
# after exiting context manager, literals are converted to Literal expressions again
"""
def __init__(self):
self._save_context = {}
def save(self):
self._save_context["default_whitespace"] = ParserElement.DEFAULT_WHITE_CHARS
self._save_context["default_keyword_chars"] = Keyword.DEFAULT_KEYWORD_CHARS
self._save_context[
"literal_string_class"
] = ParserElement._literalStringClass
self._save_context["verbose_stacktrace"] = ParserElement.verbose_stacktrace
self._save_context["packrat_enabled"] = ParserElement._packratEnabled
if ParserElement._packratEnabled:
self._save_context[
"packrat_cache_size"
] = ParserElement.packrat_cache.size
else:
self._save_context["packrat_cache_size"] = None
self._save_context["packrat_parse"] = ParserElement._parse
self._save_context[
"recursion_enabled"
] = ParserElement._left_recursion_enabled
self._save_context["__diag__"] = {
name: getattr(__diag__, name) for name in __diag__._all_names
}
self._save_context["__compat__"] = {
"collect_all_And_tokens": __compat__.collect_all_And_tokens
}
return self
def restore(self):
# reset pyparsing global state
if (
ParserElement.DEFAULT_WHITE_CHARS
!= self._save_context["default_whitespace"]
):
ParserElement.set_default_whitespace_chars(
self._save_context["default_whitespace"]
)
ParserElement.verbose_stacktrace = self._save_context["verbose_stacktrace"]
Keyword.DEFAULT_KEYWORD_CHARS = self._save_context["default_keyword_chars"]
ParserElement.inlineLiteralsUsing(
self._save_context["literal_string_class"]
)
for name, value in self._save_context["__diag__"].items():
(__diag__.enable if value else __diag__.disable)(name)
ParserElement._packratEnabled = False
if self._save_context["packrat_enabled"]:
ParserElement.enable_packrat(self._save_context["packrat_cache_size"])
else:
ParserElement._parse = self._save_context["packrat_parse"]
ParserElement._left_recursion_enabled = self._save_context[
"recursion_enabled"
]
__compat__.collect_all_And_tokens = self._save_context["__compat__"]
return self
def copy(self):
ret = type(self)()
ret._save_context.update(self._save_context)
return ret
def __enter__(self):
return self.save()
def __exit__(self, *args):
self.restore()
class TestParseResultsAsserts:
"""
A mixin class to add parse results assertion methods to normal unittest.TestCase classes.
"""
def assertParseResultsEquals(
self, result, expected_list=None, expected_dict=None, msg=None
):
"""
Unit test assertion to compare a :class:`ParseResults` object with an optional ``expected_list``,
and compare any defined results names with an optional ``expected_dict``.
"""
if expected_list is not None:
self.assertEqual(expected_list, result.as_list(), msg=msg)
if expected_dict is not None:
self.assertEqual(expected_dict, result.as_dict(), msg=msg)
def assertParseAndCheckList(
self, expr, test_string, expected_list, msg=None, verbose=True
):
"""
Convenience wrapper assert to test a parser element and input string, and assert that
the resulting ``ParseResults.asList()`` is equal to the ``expected_list``.
"""
result = expr.parse_string(test_string, parse_all=True)
if verbose:
print(result.dump())
else:
print(result.as_list())
self.assertParseResultsEquals(result, expected_list=expected_list, msg=msg)
def assertParseAndCheckDict(
self, expr, test_string, expected_dict, msg=None, verbose=True
):
"""
Convenience wrapper assert to test a parser element and input string, and assert that
the resulting ``ParseResults.asDict()`` is equal to the ``expected_dict``.
"""
result = expr.parse_string(test_string, parseAll=True)
if verbose:
print(result.dump())
else:
print(result.as_list())
self.assertParseResultsEquals(result, expected_dict=expected_dict, msg=msg)
def assertRunTestResults(
self, run_tests_report, expected_parse_results=None, msg=None
):
"""
Unit test assertion to evaluate output of ``ParserElement.runTests()``. If a list of
list-dict tuples is given as the ``expected_parse_results`` argument, then these are zipped
with the report tuples returned by ``runTests`` and evaluated using ``assertParseResultsEquals``.
Finally, asserts that the overall ``runTests()`` success value is ``True``.
:param run_tests_report: tuple(bool, [tuple(str, ParseResults or Exception)]) returned from runTests
:param expected_parse_results (optional): [tuple(str, list, dict, Exception)]
"""
run_test_success, run_test_results = run_tests_report
if expected_parse_results is not None:
merged = [
(*rpt, expected)
for rpt, expected in zip(run_test_results, expected_parse_results)
]
for test_string, result, expected in merged:
# expected should be a tuple containing a list and/or a dict or an exception,
# and optional failure message string
# an empty tuple will skip any result validation
fail_msg = next(
(exp for exp in expected if isinstance(exp, str)), None
)
expected_exception = next(
(
exp
for exp in expected
if isinstance(exp, type) and issubclass(exp, Exception)
),
None,
)
if expected_exception is not None:
with self.assertRaises(
expected_exception=expected_exception, msg=fail_msg or msg
):
if isinstance(result, Exception):
raise result
else:
expected_list = next(
(exp for exp in expected if isinstance(exp, list)), None
)
expected_dict = next(
(exp for exp in expected if isinstance(exp, dict)), None
)
if (expected_list, expected_dict) != (None, None):
self.assertParseResultsEquals(
result,
expected_list=expected_list,
expected_dict=expected_dict,
msg=fail_msg or msg,
)
else:
# warning here maybe?
print("no validation for {!r}".format(test_string))
# do this last, in case some specific test results can be reported instead
self.assertTrue(
run_test_success, msg=msg if msg is not None else "failed runTests"
)
@contextmanager
def assertRaisesParseException(self, exc_type=ParseException, msg=None):
with self.assertRaises(exc_type, msg=msg):
yield
@staticmethod
def with_line_numbers(
s: str,
start_line: typing.Optional[int] = None,
end_line: typing.Optional[int] = None,
expand_tabs: bool = True,
eol_mark: str = "|",
mark_spaces: typing.Optional[str] = None,
mark_control: typing.Optional[str] = None,
) -> str:
"""
Helpful method for debugging a parser - prints a string with line and column numbers.
(Line and column numbers are 1-based.)
:param s: tuple(bool, str - string to be printed with line and column numbers
:param start_line: int - (optional) starting line number in s to print (default=1)
:param end_line: int - (optional) ending line number in s to print (default=len(s))
:param expand_tabs: bool - (optional) expand tabs to spaces, to match the pyparsing default
:param eol_mark: str - (optional) string to mark the end of lines, helps visualize trailing spaces (default="|")
:param mark_spaces: str - (optional) special character to display in place of spaces
:param mark_control: str - (optional) convert non-printing control characters to a placeholding
character; valid values:
- "unicode" - replaces control chars with Unicode symbols, such as "␍" and "␊"
- any single character string - replace control characters with given string
- None (default) - string is displayed as-is
:return: str - input string with leading line numbers and column number headers
"""
if expand_tabs:
s = s.expandtabs()
if mark_control is not None:
if mark_control == "unicode":
tbl = str.maketrans(
{c: u for c, u in zip(range(0, 33), range(0x2400, 0x2433))}
| {127: 0x2421}
)
eol_mark = ""
else:
tbl = str.maketrans(
{c: mark_control for c in list(range(0, 32)) + [127]}
)
s = s.translate(tbl)
if mark_spaces is not None and mark_spaces != " ":
if mark_spaces == "unicode":
tbl = str.maketrans({9: 0x2409, 32: 0x2423})
s = s.translate(tbl)
else:
s = s.replace(" ", mark_spaces)
if start_line is None:
start_line = 1
if end_line is None:
end_line = len(s)
end_line = min(end_line, len(s))
start_line = min(max(1, start_line), end_line)
if mark_control != "unicode":
s_lines = s.splitlines()[start_line - 1 : end_line]
else:
s_lines = [line + "␊" for line in s.split("␊")[start_line - 1 : end_line]]
if not s_lines:
return ""
lineno_width = len(str(end_line))
max_line_len = max(len(line) for line in s_lines)
lead = " " * (lineno_width + 1)
if max_line_len >= 99:
header0 = (
lead
+ "".join(
"{}{}".format(" " * 99, (i + 1) % 100)
for i in range(max(max_line_len // 100, 1))
)
+ "\n"
)
else:
header0 = ""
header1 = (
header0
+ lead
+ "".join(
" {}".format((i + 1) % 10)
for i in range(-(-max_line_len // 10))
)
+ "\n"
)
header2 = lead + "1234567890" * (-(-max_line_len // 10)) + "\n"
return (
header1
+ header2
+ "\n".join(
"{:{}d}:{}{}".format(i, lineno_width, line, eol_mark)
for i, line in enumerate(s_lines, start=start_line)
)
+ "\n"
)