Testing Predicate Assertion Generation in Telegram
This Python script generates Google Test predicate assertion implementations and unit tests for testing predicate-based assertions in the Telegram codebase. It creates header files and test files that validate predicate functions with varying arities and supports both format and non-format predicate testing.
Test Coverage Overview
Implementation Analysis
Technical Details
Best Practices Demonstrated
drklo/telegram
TMessagesProj/jni/boringssl/third_party/googletest/scripts/gen_gtest_pred_impl.py
#!/usr/bin/env python
#
# Copyright 2006, Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""gen_gtest_pred_impl.py v0.1
Generates the implementation of Google Test predicate assertions and
accompanying tests.
Usage:
gen_gtest_pred_impl.py MAX_ARITY
where MAX_ARITY is a positive integer.
The command generates the implementation of up-to MAX_ARITY-ary
predicate assertions, and writes it to file gtest_pred_impl.h in the
directory where the script is. It also generates the accompanying
unit test in file gtest_pred_impl_unittest.cc.
"""
__author__ = '[email protected] (Zhanyong Wan)'
import os
import sys
import time
# Where this script is.
SCRIPT_DIR = os.path.dirname(sys.argv[0])
# Where to store the generated header.
HEADER = os.path.join(SCRIPT_DIR, '../include/gtest/gtest_pred_impl.h')
# Where to store the generated unit test.
UNIT_TEST = os.path.join(SCRIPT_DIR, '../test/gtest_pred_impl_unittest.cc')
def HeaderPreamble(n):
"""Returns the preamble for the header file.
Args:
n: the maximum arity of the predicate macros to be generated.
"""
# A map that defines the values used in the preamble template.
DEFS = {
'today' : time.strftime('%m/%d/%Y'),
'year' : time.strftime('%Y'),
'command' : '%s %s' % (os.path.basename(sys.argv[0]), n),
'n' : n
}
return (
"""// Copyright 2006, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// This file is AUTOMATICALLY GENERATED on %(today)s by command
// '%(command)s'. DO NOT EDIT BY HAND!
//
// Implements a family of generic predicate assertion macros.
#ifndef GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
#define GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
#include "gtest/gtest.h"
namespace testing {
// This header implements a family of generic predicate assertion
// macros:
//
// ASSERT_PRED_FORMAT1(pred_format, v1)
// ASSERT_PRED_FORMAT2(pred_format, v1, v2)
// ...
//
// where pred_format is a function or functor that takes n (in the
// case of ASSERT_PRED_FORMATn) values and their source expression
// text, and returns a testing::AssertionResult. See the definition
// of ASSERT_EQ in gtest.h for an example.
//
// If you don't care about formatting, you can use the more
// restrictive version:
//
// ASSERT_PRED1(pred, v1)
// ASSERT_PRED2(pred, v1, v2)
// ...
//
// where pred is an n-ary function or functor that returns bool,
// and the values v1, v2, ..., must support the << operator for
// streaming to std::ostream.
//
// We also define the EXPECT_* variations.
//
// For now we only support predicates whose arity is at most %(n)s.
// Please email [email protected] if you need
// support for higher arities.
// GTEST_ASSERT_ is the basic statement to which all of the assertions
// in this file reduce. Don't use this in your code.
#define GTEST_ASSERT_(expression, on_failure) \\
GTEST_AMBIGUOUS_ELSE_BLOCKER_ \\
if (const ::testing::AssertionResult gtest_ar = (expression)) \\
; \\
else \\
on_failure(gtest_ar.failure_message())
""" % DEFS)
def Arity(n):
"""Returns the English name of the given arity."""
if n < 0:
return None
elif n <= 3:
return ['nullary', 'unary', 'binary', 'ternary'][n]
else:
return '%s-ary' % n
def Title(word):
"""Returns the given word in title case. The difference between
this and string's title() method is that Title('4-ary') is '4-ary'
while '4-ary'.title() is '4-Ary'."""
return word[0].upper() + word[1:]
def OneTo(n):
"""Returns the list [1, 2, 3, ..., n]."""
return range(1, n + 1)
def Iter(n, format, sep=''):
"""Given a positive integer n, a format string that contains 0 or
more '%s' format specs, and optionally a separator string, returns
the join of n strings, each formatted with the format string on an
iterator ranged from 1 to n.
Example:
Iter(3, 'v%s', sep=', ') returns 'v1, v2, v3'.
"""
# How many '%s' specs are in format?
spec_count = len(format.split('%s')) - 1
return sep.join([format % (spec_count * (i,)) for i in OneTo(n)])
def ImplementationForArity(n):
"""Returns the implementation of n-ary predicate assertions."""
# A map the defines the values used in the implementation template.
DEFS = {
'n' : str(n),
'vs' : Iter(n, 'v%s', sep=', '),
'vts' : Iter(n, '#v%s', sep=', '),
'arity' : Arity(n),
'Arity' : Title(Arity(n))
}
impl = """
// Helper function for implementing {EXPECT|ASSERT}_PRED%(n)s. Don't use
// this in your code.
template <typename Pred""" % DEFS
impl += Iter(n, """,
typename T%s""")
impl += """>
AssertionResult AssertPred%(n)sHelper(const char* pred_text""" % DEFS
impl += Iter(n, """,
const char* e%s""")
impl += """,
Pred pred"""
impl += Iter(n, """,
const T%s& v%s""")
impl += """) {
if (pred(%(vs)s)) return AssertionSuccess();
""" % DEFS
impl += ' return AssertionFailure() << pred_text << "("'
impl += Iter(n, """
<< e%s""", sep=' << ", "')
impl += ' << ") evaluates to false, where"'
impl += Iter(n, """
<< "\\n" << e%s << " evaluates to " << v%s""")
impl += """;
}
// Internal macro for implementing {EXPECT|ASSERT}_PRED_FORMAT%(n)s.
// Don't use this in your code.
#define GTEST_PRED_FORMAT%(n)s_(pred_format, %(vs)s, on_failure)\\
GTEST_ASSERT_(pred_format(%(vts)s, %(vs)s), \\
on_failure)
// Internal macro for implementing {EXPECT|ASSERT}_PRED%(n)s. Don't use
// this in your code.
#define GTEST_PRED%(n)s_(pred, %(vs)s, on_failure)\\
GTEST_ASSERT_(::testing::AssertPred%(n)sHelper(#pred""" % DEFS
impl += Iter(n, """, \\
#v%s""")
impl += """, \\
pred"""
impl += Iter(n, """, \\
v%s""")
impl += """), on_failure)
// %(Arity)s predicate assertion macros.
#define EXPECT_PRED_FORMAT%(n)s(pred_format, %(vs)s) \\
GTEST_PRED_FORMAT%(n)s_(pred_format, %(vs)s, GTEST_NONFATAL_FAILURE_)
#define EXPECT_PRED%(n)s(pred, %(vs)s) \\
GTEST_PRED%(n)s_(pred, %(vs)s, GTEST_NONFATAL_FAILURE_)
#define ASSERT_PRED_FORMAT%(n)s(pred_format, %(vs)s) \\
GTEST_PRED_FORMAT%(n)s_(pred_format, %(vs)s, GTEST_FATAL_FAILURE_)
#define ASSERT_PRED%(n)s(pred, %(vs)s) \\
GTEST_PRED%(n)s_(pred, %(vs)s, GTEST_FATAL_FAILURE_)
""" % DEFS
return impl
def HeaderPostamble():
"""Returns the postamble for the header file."""
return """
} // namespace testing
#endif // GTEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
"""
def GenerateFile(path, content):
"""Given a file path and a content string
overwrites it with the given content.
"""
print 'Updating file %s . . .' % path
f = file(path, 'w+')
print >>f, content,
f.close()
print 'File %s has been updated.' % path
def GenerateHeader(n):
"""Given the maximum arity n, updates the header file that implements
the predicate assertions.
"""
GenerateFile(HEADER,
HeaderPreamble(n)
+ ''.join([ImplementationForArity(i) for i in OneTo(n)])
+ HeaderPostamble())
def UnitTestPreamble():
"""Returns the preamble for the unit test file."""
# A map that defines the values used in the preamble template.
DEFS = {
'today' : time.strftime('%m/%d/%Y'),
'year' : time.strftime('%Y'),
'command' : '%s %s' % (os.path.basename(sys.argv[0]), sys.argv[1]),
}
return (
"""// Copyright 2006, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// This file is AUTOMATICALLY GENERATED on %(today)s by command
// '%(command)s'. DO NOT EDIT BY HAND!
// Regression test for gtest_pred_impl.h
//
// This file is generated by a script and quite long. If you intend to
// learn how Google Test works by reading its unit tests, read
// gtest_unittest.cc instead.
//
// This is intended as a regression test for the Google Test predicate
// assertions. We compile it as part of the gtest_unittest target
// only to keep the implementation tidy and compact, as it is quite
// involved to set up the stage for testing Google Test using Google
// Test itself.
//
// Currently, gtest_unittest takes ~11 seconds to run in the testing
// daemon. In the future, if it grows too large and needs much more
// time to finish, we should consider separating this file into a
// stand-alone regression test.
#include <iostream>
#include "gtest/gtest.h"
#include "gtest/gtest-spi.h"
// A user-defined data type.
struct Bool {
explicit Bool(int val) : value(val != 0) {}
bool operator>(int n) const { return value > Bool(n).value; }
Bool operator+(const Bool& rhs) const { return Bool(value + rhs.value); }
bool operator==(const Bool& rhs) const { return value == rhs.value; }
bool value;
};
// Enables Bool to be used in assertions.
std::ostream& operator<<(std::ostream& os, const Bool& x) {
return os << (x.value ? "true" : "false");
}
""" % DEFS)
def TestsForArity(n):
"""Returns the tests for n-ary predicate assertions."""
# A map that defines the values used in the template for the tests.
DEFS = {
'n' : n,
'es' : Iter(n, 'e%s', sep=', '),
'vs' : Iter(n, 'v%s', sep=', '),
'vts' : Iter(n, '#v%s', sep=', '),
'tvs' : Iter(n, 'T%s v%s', sep=', '),
'int_vs' : Iter(n, 'int v%s', sep=', '),
'Bool_vs' : Iter(n, 'Bool v%s', sep=', '),
'types' : Iter(n, 'typename T%s', sep=', '),
'v_sum' : Iter(n, 'v%s', sep=' + '),
'arity' : Arity(n),
'Arity' : Title(Arity(n)),
}
tests = (
"""// Sample functions/functors for testing %(arity)s predicate assertions.
// A %(arity)s predicate function.
template <%(types)s>
bool PredFunction%(n)s(%(tvs)s) {
return %(v_sum)s > 0;
}
// The following two functions are needed to circumvent a bug in
// gcc 2.95.3, which sometimes has problem with the above template
// function.
bool PredFunction%(n)sInt(%(int_vs)s) {
return %(v_sum)s > 0;
}
bool PredFunction%(n)sBool(%(Bool_vs)s) {
return %(v_sum)s > 0;
}
""" % DEFS)
tests += """
// A %(arity)s predicate functor.
struct PredFunctor%(n)s {
template <%(types)s>
bool operator()(""" % DEFS
tests += Iter(n, 'const T%s& v%s', sep=""",
""")
tests += """) {
return %(v_sum)s > 0;
}
};
""" % DEFS
tests += """
// A %(arity)s predicate-formatter function.
template <%(types)s>
testing::AssertionResult PredFormatFunction%(n)s(""" % DEFS
tests += Iter(n, 'const char* e%s', sep=""",
""")
tests += Iter(n, """,
const T%s& v%s""")
tests += """) {
if (PredFunction%(n)s(%(vs)s))
return testing::AssertionSuccess();
return testing::AssertionFailure()
<< """ % DEFS
tests += Iter(n, 'e%s', sep=' << " + " << ')
tests += """
<< " is expected to be positive, but evaluates to "
<< %(v_sum)s << ".";
}
""" % DEFS
tests += """
// A %(arity)s predicate-formatter functor.
struct PredFormatFunctor%(n)s {
template <%(types)s>
testing::AssertionResult operator()(""" % DEFS
tests += Iter(n, 'const char* e%s', sep=""",
""")
tests += Iter(n, """,
const T%s& v%s""")
tests += """) const {
return PredFormatFunction%(n)s(%(es)s, %(vs)s);
}
};
""" % DEFS
tests += """
// Tests for {EXPECT|ASSERT}_PRED_FORMAT%(n)s.
class Predicate%(n)sTest : public testing::Test {
protected:
virtual void SetUp() {
expected_to_finish_ = true;
finished_ = false;""" % DEFS
tests += """
""" + Iter(n, 'n%s_ = ') + """0;
}
"""
tests += """
virtual void TearDown() {
// Verifies that each of the predicate's arguments was evaluated
// exactly once."""
tests += ''.join(["""
EXPECT_EQ(1, n%s_) <<
"The predicate assertion didn't evaluate argument %s "
"exactly once.";""" % (i, i + 1) for i in OneTo(n)])
tests += """
// Verifies that the control flow in the test function is expected.
if (expected_to_finish_ && !finished_) {
FAIL() << "The predicate assertion unexpactedly aborted the test.";
} else if (!expected_to_finish_ && finished_) {
FAIL() << "The failed predicate assertion didn't abort the test "
"as expected.";
}
}
// true iff the test function is expected to run to finish.
static bool expected_to_finish_;
// true iff the test function did run to finish.
static bool finished_;
""" % DEFS
tests += Iter(n, """
static int n%s_;""")
tests += """
};
bool Predicate%(n)sTest::expected_to_finish_;
bool Predicate%(n)sTest::finished_;
""" % DEFS
tests += Iter(n, """int Predicate%%(n)sTest::n%s_;
""") % DEFS
tests += """
typedef Predicate%(n)sTest EXPECT_PRED_FORMAT%(n)sTest;
typedef Predicate%(n)sTest ASSERT_PRED_FORMAT%(n)sTest;
typedef Predicate%(n)sTest EXPECT_PRED%(n)sTest;
typedef Predicate%(n)sTest ASSERT_PRED%(n)sTest;
""" % DEFS
def GenTest(use_format, use_assert, expect_failure,
use_functor, use_user_type):
"""Returns the test for a predicate assertion macro.
Args:
use_format: true iff the assertion is a *_PRED_FORMAT*.
use_assert: true iff the assertion is a ASSERT_*.
expect_failure: true iff the assertion is expected to fail.
use_functor: true iff the first argument of the assertion is
a functor (as opposed to a function)
use_user_type: true iff the predicate functor/function takes
argument(s) of a user-defined type.
Example:
GenTest(1, 0, 0, 1, 0) returns a test that tests the behavior
of a successful EXPECT_PRED_FORMATn() that takes a functor
whose arguments have built-in types."""
if use_assert:
assrt = 'ASSERT' # 'assert' is reserved, so we cannot use
# that identifier here.
else:
assrt = 'EXPECT'
assertion = assrt + '_PRED'
if use_format:
pred_format = 'PredFormat'
assertion += '_FORMAT'
else:
pred_format = 'Pred'
assertion += '%(n)s' % DEFS
if use_functor:
pred_format_type = 'functor'
pred_format += 'Functor%(n)s()'
else:
pred_format_type = 'function'
pred_format += 'Function%(n)s'
if not use_format:
if use_user_type:
pred_format += 'Bool'
else:
pred_format += 'Int'
test_name = pred_format_type.title()
if use_user_type:
arg_type = 'user-defined type (Bool)'
test_name += 'OnUserType'
if expect_failure:
arg = 'Bool(n%s_++)'
else:
arg = 'Bool(++n%s_)'
else:
arg_type = 'built-in type (int)'
test_name += 'OnBuiltInType'
if expect_failure:
arg = 'n%s_++'
else:
arg = '++n%s_'
if expect_failure:
successful_or_failed = 'failed'
expected_or_not = 'expected.'
test_name += 'Failure'
else:
successful_or_failed = 'successful'
expected_or_not = 'UNEXPECTED!'
test_name += 'Success'
# A map that defines the values used in the test template.
defs = DEFS.copy()
defs.update({
'assert' : assrt,
'assertion' : assertion,
'test_name' : test_name,
'pf_type' : pred_format_type,
'pf' : pred_format,
'arg_type' : arg_type,
'arg' : arg,
'successful' : successful_or_failed,
'expected' : expected_or_not,
})
test = """
// Tests a %(successful)s %(assertion)s where the
// predicate-formatter is a %(pf_type)s on a %(arg_type)s.
TEST_F(%(assertion)sTest, %(test_name)s) {""" % defs
indent = (len(assertion) + 3)*' '
extra_indent = ''
if expect_failure:
extra_indent = ' '
if use_assert:
test += """
expected_to_finish_ = false;
EXPECT_FATAL_FAILURE({ // NOLINT"""
else:
test += """
EXPECT_NONFATAL_FAILURE({ // NOLINT"""
test += '\n' + extra_indent + """ %(assertion)s(%(pf)s""" % defs
test = test % defs
test += Iter(n, ',\n' + indent + extra_indent + '%(arg)s' % defs)
test += ');\n' + extra_indent + ' finished_ = true;\n'
if expect_failure:
test += ' }, "");\n'
test += '}\n'
return test
# Generates tests for all 2**6 = 64 combinations.
tests += ''.join([GenTest(use_format, use_assert, expect_failure,
use_functor, use_user_type)
for use_format in [0, 1]
for use_assert in [0, 1]
for expect_failure in [0, 1]
for use_functor in [0, 1]
for use_user_type in [0, 1]
])
return tests
def UnitTestPostamble():
"""Returns the postamble for the tests."""
return ''
def GenerateUnitTest(n):
"""Returns the tests for up-to n-ary predicate assertions."""
GenerateFile(UNIT_TEST,
UnitTestPreamble()
+ ''.join([TestsForArity(i) for i in OneTo(n)])
+ UnitTestPostamble())
def _Main():
"""The entry point of the script. Generates the header file and its
unit test."""
if len(sys.argv) != 2:
print __doc__
print 'Author: ' + __author__
sys.exit(1)
n = int(sys.argv[1])
GenerateHeader(n)
GenerateUnitTest(n)
if __name__ == '__main__':
_Main()