meson/run_unittests.py

#!/usr/bin/env python3
# Copyright 2016 The Meson development team

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import unittest, os, sys, shutil, time
import subprocess
import re, json
import tempfile
from glob import glob
import mesonbuild.environment
from mesonbuild.environment import detect_ninja, Environment
from mesonbuild.dependencies import PkgConfigDependency

def get_soname(fname):
    # HACK, fix to not use shell.
    raw_out = subprocess.check_output(['readelf', '-a', fname],
                                      universal_newlines=True)
    pattern = re.compile('soname: \[(.*?)\]')
    for line in raw_out.split('\n'):
        m = pattern.search(line)
        if m is not None:
            return m.group(1)
    raise RuntimeError('Could not determine soname:\n\n' + raw_out)

def get_fake_options(prefix):
    import argparse
    opts = argparse.Namespace()
    opts.cross_file = None
    opts.prefix = prefix
    return opts

class FakeEnvironment(object):
    def __init__(self):
        self.cross_info = None

    def is_cross_build(self):
        return False

class InternalTests(unittest.TestCase):

    def test_version_number(self):
        searchfunc = mesonbuild.environment.search_version
        self.assertEqual(searchfunc('foobar 1.2.3'), '1.2.3')
        self.assertEqual(searchfunc('1.2.3'), '1.2.3')
        self.assertEqual(searchfunc('foobar 2016.10.28 1.2.3'), '1.2.3')
        self.assertEqual(searchfunc('2016.10.28 1.2.3'), '1.2.3')
        self.assertEqual(searchfunc('foobar 2016.10.128'), 'unknown version')
        self.assertEqual(searchfunc('2016.10.128'), 'unknown version')

class LinuxlikeTests(unittest.TestCase):
    def setUp(self):
        super().setUp()
        src_root = os.path.dirname(__file__)
        src_root = os.path.join(os.getcwd(), src_root)
        self.builddir = tempfile.mkdtemp()
        self.logdir = os.path.join(self.builddir, 'meson-logs')
        self.prefix = '/usr'
        self.libdir = os.path.join(self.prefix, 'lib')
        self.installdir = os.path.join(self.builddir, 'install')
        self.meson_command = [sys.executable, os.path.join(src_root, 'meson.py')]
        self.mconf_command = [sys.executable, os.path.join(src_root, 'mesonconf.py')]
        self.mintro_command = [sys.executable, os.path.join(src_root, 'mesonintrospect.py')]
        self.mtest_command = [sys.executable, os.path.join(src_root, 'mesontest.py'), '-C', self.builddir]
        self.ninja_command = [detect_ninja(), '-C', self.builddir]
        self.common_test_dir = os.path.join(src_root, 'test cases/common')
        self.vala_test_dir = os.path.join(src_root, 'test cases/vala')
        self.framework_test_dir = os.path.join(src_root, 'test cases/frameworks')
        self.unit_test_dir = os.path.join(src_root, 'test cases/unit')
        self.output = b''
        self.orig_env = os.environ.copy()

    def tearDown(self):
        shutil.rmtree(self.builddir)
        os.environ = self.orig_env
        super().tearDown()

    def _run(self, command):
        self.output += subprocess.check_output(command, stderr=subprocess.STDOUT,
                                               env=os.environ.copy())

    def init(self, srcdir, extra_args=None):
        if extra_args is None:
            extra_args = []
        args = [srcdir, self.builddir,
                '--prefix', self.prefix,
                '--libdir', self.libdir]
        self._run(self.meson_command + args + extra_args)
        self.privatedir = os.path.join(self.builddir, 'meson-private')

    def build(self):
        self._run(self.ninja_command)

    def run_tests(self):
        self._run(self.ninja_command + ['test'])

    def install(self):
        os.environ['DESTDIR'] = self.installdir
        self._run(self.ninja_command + ['install'])

    def uninstall(self):
        self._run(self.ninja_command + ['uninstall'])

    def run_target(self, target):
        self.output += subprocess.check_output(self.ninja_command + [target])

    def setconf(self, arg):
        self._run(self.mconf_command + [arg, self.builddir])

    def wipe(self):
        shutil.rmtree(self.builddir)

    def get_compdb(self):
        with open(os.path.join(self.builddir, 'compile_commands.json')) as ifile:
            return json.load(ifile)

    def get_meson_log(self):
        with open(os.path.join(self.builddir, 'meson-logs', 'meson-log.txt')) as f:
            return f.readlines()

    def get_meson_log_compiler_checks(self):
        '''
        Fetch a list command-lines run by meson for compiler checks.
        Each command-line is returned as a list of arguments.
        '''
        log = self.get_meson_log()
        prefix = 'Command line:'
        cmds = [l[len(prefix):].split() for l in log if l.startswith(prefix)]
        return cmds

    def introspect(self, arg):
        out = subprocess.check_output(self.mintro_command + [arg, self.builddir],
                                      universal_newlines=True)
        return json.loads(out)

    def test_basic_soname(self):
        '''
        Test that the soname is set correctly for shared libraries. This can't
        be an ordinary test case because we need to run `readelf` and actually
        check the soname.
        https://github.com/mesonbuild/meson/issues/785
        '''
        testdir = os.path.join(self.common_test_dir, '4 shared')
        self.init(testdir)
        self.build()
        lib1 = os.path.join(self.builddir, 'libmylib.so')
        soname = get_soname(lib1)
        self.assertEqual(soname, 'libmylib.so')

    def test_custom_soname(self):
        '''
        Test that the soname is set correctly for shared libraries when
        a custom prefix and/or suffix is used. This can't be an ordinary test
        case because we need to run `readelf` and actually check the soname.
        https://github.com/mesonbuild/meson/issues/785
        '''
        testdir = os.path.join(self.common_test_dir, '27 library versions')
        self.init(testdir)
        self.build()
        lib1 = os.path.join(self.builddir, 'prefixsomelib.suffix')
        soname = get_soname(lib1)
        self.assertEqual(soname, 'prefixsomelib.suffix')

    def test_pic(self):
        '''
        Test that -fPIC is correctly added to static libraries when b_staticpic
        is true and not when it is false. This can't be an ordinary test case
        because we need to inspect the compiler database.
        '''
        testdir = os.path.join(self.common_test_dir, '3 static')
        self.init(testdir)
        compdb = self.get_compdb()
        self.assertIn('-fPIC', compdb[0]['command'])
        # This is needed to increase the difference between build.ninja's
        # timestamp and coredata.dat's timestamp due to a Ninja bug.
        # https://github.com/ninja-build/ninja/issues/371
        time.sleep(1)
        self.setconf('-Db_staticpic=false')
        # Regenerate build
        self.build()
        compdb = self.get_compdb()
        self.assertNotIn('-fPIC', compdb[0]['command'])

    def test_pkgconfig_gen(self):
        '''
        Test that generated pkg-config files can be found and have the correct
        version and link args. This can't be an ordinary test case because we
        need to run pkg-config outside of a Meson build file.
        https://github.com/mesonbuild/meson/issues/889
        '''
        testdir = os.path.join(self.common_test_dir, '51 pkgconfig-gen')
        self.init(testdir)
        env = FakeEnvironment()
        kwargs = {'required': True, 'silent': True}
        os.environ['PKG_CONFIG_LIBDIR'] = self.privatedir
        simple_dep = PkgConfigDependency('libfoo', env, kwargs)
        self.assertTrue(simple_dep.found())
        self.assertEqual(simple_dep.get_version(), '1.0')
        self.assertIn('-lfoo', simple_dep.get_link_args())

    def test_vala_c_warnings(self):
        '''
        Test that no warnings are emitted for C code generated by Vala. This
        can't be an ordinary test case because we need to inspect the compiler
        database.
        https://github.com/mesonbuild/meson/issues/864
        '''
        testdir = os.path.join(self.vala_test_dir, '5 target glib')
        self.init(testdir)
        compdb = self.get_compdb()
        vala_command = None
        c_command = None
        for each in compdb:
            if each['file'].endswith('GLib.Thread.c'):
                vala_command = each['command']
            elif each['file'].endswith('retcode.c'):
                c_command = each['command']
            else:
                m = 'Unknown file {!r} in vala_c_warnings test'.format(each['file'])
                raise AssertionError(m)
        self.assertIsNotNone(vala_command)
        self.assertIsNotNone(c_command)
        # -w suppresses all warnings, should be there in Vala but not in C
        self.assertIn("'-w'", vala_command)
        self.assertNotIn("'-w'", c_command)
        # -Wall enables all warnings, should be there in C but not in Vala
        self.assertNotIn("'-Wall'", vala_command)
        self.assertIn("'-Wall'", c_command)
        # -Werror converts warnings to errors, should always be there since it's
        # injected by an unrelated piece of code and the project has werror=true
        self.assertIn("'-Werror'", vala_command)
        self.assertIn("'-Werror'", c_command)

    def test_static_compile_order(self):
        '''
        Test that the order of files in a compiler command-line while compiling
        and linking statically is deterministic. This can't be an ordinary test
        case because we need to inspect the compiler database.
        https://github.com/mesonbuild/meson/pull/951
        '''
        testdir = os.path.join(self.common_test_dir, '5 linkstatic')
        self.init(testdir)
        compdb = self.get_compdb()
        # Rules will get written out in this order
        self.assertTrue(compdb[0]['file'].endswith("libfile.c"))
        self.assertTrue(compdb[1]['file'].endswith("libfile2.c"))
        self.assertTrue(compdb[2]['file'].endswith("libfile3.c"))
        self.assertTrue(compdb[3]['file'].endswith("libfile4.c"))
        # FIXME: We don't have access to the linker command

    def test_install_introspection(self):
        '''
        Tests that the Meson introspection API exposes install filenames correctly
        https://github.com/mesonbuild/meson/issues/829
        '''
        testdir = os.path.join(self.common_test_dir, '8 install')
        self.init(testdir)
        intro = self.introspect('--targets')
        if intro[0]['type'] == 'executable':
            intro = intro[::-1]
        self.assertEqual(intro[0]['install_filename'], '/usr/lib/libstat.a')
        self.assertEqual(intro[1]['install_filename'], '/usr/bin/prog')

    def test_run_target_files_path(self):
        '''
        Test that run_targets are run from the correct directory
        https://github.com/mesonbuild/meson/issues/957
        '''
        testdir = os.path.join(self.common_test_dir, '58 run target')
        self.init(testdir)
        self.run_target('check_exists')

    def test_qt5dependency_qmake_detection(self):
        '''
        Test that qt5 detection with qmake works. This can't be an ordinary
        test case because it involves setting the environment.
        '''
        # Verify that qmake is for Qt5
        if not shutil.which('qmake-qt5'):
            if not shutil.which('qmake'):
                raise unittest.SkipTest('QMake not found')
            # For some inexplicable reason qmake --version gives different
            # results when run from the command line vs invoked by Python.
            # Check for both cases in case this behaviour changes in the future.
            output = subprocess.getoutput(['qmake', '--version'])
            if 'Qt version 5' not in output and 'qt5' not in output:
                raise unittest.SkipTest('Qmake found, but it is not for Qt 5.')
        # Disable pkg-config codepath and force searching with qmake/qmake-qt5
        os.environ['PKG_CONFIG_LIBDIR'] = self.builddir
        os.environ['PKG_CONFIG_PATH'] = self.builddir
        testdir = os.path.join(self.framework_test_dir, '4 qt')
        self.init(testdir)
        # Confirm that the dependency was found with qmake
        msg = 'Qt5 native `qmake-qt5` dependency (modules: Core) found: YES\n'
        msg2 = 'Qt5 native `qmake` dependency (modules: Core) found: YES\n'
        mesonlog = self.get_meson_log()
        self.assertTrue(msg in mesonlog or msg2 in mesonlog)

    def get_soname(self, fname):
        output = subprocess.check_output(['readelf', '-a', fname],
                                         universal_newlines=True)
        for line in output.split('\n'):
            if 'SONAME' in line:
                return line.split('[')[1].split(']')[0]
        raise RuntimeError('Readelf gave no SONAME.')

    def _test_soname_impl(self, libpath, install):
        testdir = os.path.join(self.unit_test_dir, '1 soname')
        self.init(testdir)
        self.build()
        if install:
            self.install()

        # File without aliases set.
        nover = os.path.join(libpath, 'libnover.so')
        self.assertTrue(os.path.exists(nover))
        self.assertFalse(os.path.islink(nover))
        self.assertEqual(self.get_soname(nover), 'libnover.so')
        self.assertEqual(len(glob(nover[:-3] + '*')), 1)

        # File with version set
        verset = os.path.join(libpath, 'libverset.so')
        self.assertTrue(os.path.exists(verset + '.4.5.6'))
        self.assertEqual(os.readlink(verset), 'libverset.so.4')
        self.assertEqual(self.get_soname(verset), 'libverset.so.4')
        self.assertEqual(len(glob(verset[:-3] + '*')), 3)

        # File with soversion set
        soverset = os.path.join(libpath, 'libsoverset.so')
        self.assertTrue(os.path.exists(soverset + '.1.2.3'))
        self.assertEqual(os.readlink(soverset), 'libsoverset.so.1.2.3')
        self.assertEqual(self.get_soname(soverset), 'libsoverset.so.1.2.3')
        self.assertEqual(len(glob(soverset[:-3] + '*')), 2)

        # File with version and soversion set to same values
        settosame = os.path.join(libpath, 'libsettosame.so')
        self.assertTrue(os.path.exists(settosame + '.7.8.9'))
        self.assertEqual(os.readlink(settosame), 'libsettosame.so.7.8.9')
        self.assertEqual(self.get_soname(settosame), 'libsettosame.so.7.8.9')
        self.assertEqual(len(glob(settosame[:-3] + '*')), 2)

        # File with version and soversion set to different values
        bothset = os.path.join(libpath, 'libbothset.so')
        self.assertTrue(os.path.exists(bothset + '.1.2.3'))
        self.assertEqual(os.readlink(bothset), 'libbothset.so.1.2.3')
        self.assertEqual(os.readlink(bothset + '.1.2.3'), 'libbothset.so.4.5.6')
        self.assertEqual(self.get_soname(bothset), 'libbothset.so.1.2.3')
        self.assertEqual(len(glob(bothset[:-3] + '*')), 3)

    def test_soname(self):
        self._test_soname_impl(self.builddir, False)

    def test_installed_soname(self):
        self._test_soname_impl(self.installdir + self.libdir, True)

    def test_compiler_check_flags_order(self):
        '''
        Test that compiler check flags override all other flags. This can't be
        an ordinary test case because it needs the environment to be set.
        '''
        Oflag = '-O3'
        os.environ['CFLAGS'] = os.environ['CXXFLAGS'] = Oflag
        testdir = os.path.join(self.common_test_dir, '43 has function')
        self.init(testdir)
        cmds = self.get_meson_log_compiler_checks()
        for cmd in cmds:
            if cmd[0] == 'ccache':
                cmd = cmd[1:]
            # Verify that -I flags from the `args` kwarg are first
            # This is set in the '43 has function' test case
            self.assertEqual(cmd[2], '-I/tmp')
            # Verify that -O3 set via the environment is overriden by -O0
            Oargs = [arg for arg in cmd if arg.startswith('-O')]
            self.assertEqual(Oargs, [Oflag, '-O0'])

    def test_uninstall(self):
        exename = os.path.join(self.installdir, 'usr/bin/prog')
        testdir = os.path.join(self.common_test_dir, '8 install')
        self.init(testdir)
        self.assertFalse(os.path.exists(exename))
        self.install()
        self.assertTrue(os.path.exists(exename))
        self.uninstall()
        self.assertFalse(os.path.exists(exename))

    def test_custom_target_exe_data_deterministic(self):
        testdir = os.path.join(self.common_test_dir, '117 custom target capture')
        self.init(testdir)
        meson_exe_dat1 = glob(os.path.join(self.privatedir, 'meson_exe*.dat'))
        self.wipe()
        self.init(testdir)
        meson_exe_dat2 = glob(os.path.join(self.privatedir, 'meson_exe*.dat'))
        self.assertListEqual(meson_exe_dat1, meson_exe_dat2)

    def test_testsetups(self):
        if not shutil.which('valgrind'):
                raise unittest.SkipTest('Valgrind not installed.')
        testdir = os.path.join(self.unit_test_dir, '2 testsetups')
        self.init(testdir)
        self.build()
        self.run_tests()
        with open(os.path.join(self.logdir, 'testlog.txt')) as f:
            basic_log = f.read()
        self.assertRaises(subprocess.CalledProcessError,
                          self._run, self.mtest_command + ['--setup=valgrind'])
        with open(os.path.join(self.logdir, 'testlog-valgrind.txt')) as f:
            vg_log = f.read()
        self.assertFalse('TEST_ENV is set' in basic_log)
        self.assertFalse('Memcheck' in basic_log)
        self.assertTrue('TEST_ENV is set' in vg_log)
        self.assertTrue('Memcheck' in vg_log)

    def assertFailedTestCount(self, failure_count, command):
        try:
            self._run(command)
            self.assertEqual(0, failure_count, 'Expected %d tests to fail.' % failure_count)
        except subprocess.CalledProcessError as e:
            self.assertEqual(e.returncode, failure_count)

    def test_suite_selection(self):
        testdir = os.path.join(self.unit_test_dir, '4 suite selection')
        self.init(testdir)
        self.build()

        self.assertFailedTestCount(3, self.mtest_command)

        self.assertFailedTestCount(0, self.mtest_command + ['--suite', ':success'])
        self.assertFailedTestCount(3, self.mtest_command + ['--suite', ':fail'])
        self.assertFailedTestCount(3, self.mtest_command + ['--no-suite', ':success'])
        self.assertFailedTestCount(0, self.mtest_command + ['--no-suite', ':fail'])

        self.assertFailedTestCount(1, self.mtest_command + ['--suite', 'mainprj'])
        self.assertFailedTestCount(0, self.mtest_command + ['--suite', 'subprjsucc'])
        self.assertFailedTestCount(1, self.mtest_command + ['--suite', 'subprjfail'])
        self.assertFailedTestCount(1, self.mtest_command + ['--suite', 'subprjmix'])
        self.assertFailedTestCount(2, self.mtest_command + ['--no-suite', 'mainprj'])
        self.assertFailedTestCount(3, self.mtest_command + ['--no-suite', 'subprjsucc'])
        self.assertFailedTestCount(2, self.mtest_command + ['--no-suite', 'subprjfail'])
        self.assertFailedTestCount(2, self.mtest_command + ['--no-suite', 'subprjmix'])

        self.assertFailedTestCount(1, self.mtest_command + ['--suite', 'mainprj:fail'])
        self.assertFailedTestCount(0, self.mtest_command + ['--suite', 'mainprj:success'])
        self.assertFailedTestCount(2, self.mtest_command + ['--no-suite', 'mainprj:fail'])
        self.assertFailedTestCount(3, self.mtest_command + ['--no-suite', 'mainprj:success'])

        self.assertFailedTestCount(1, self.mtest_command + ['--suite', 'subprjfail:fail'])
        self.assertFailedTestCount(0, self.mtest_command + ['--suite', 'subprjfail:success'])
        self.assertFailedTestCount(2, self.mtest_command + ['--no-suite', 'subprjfail:fail'])
        self.assertFailedTestCount(3, self.mtest_command + ['--no-suite', 'subprjfail:success'])

        self.assertFailedTestCount(0, self.mtest_command + ['--suite', 'subprjsucc:fail'])
        self.assertFailedTestCount(0, self.mtest_command + ['--suite', 'subprjsucc:success'])
        self.assertFailedTestCount(3, self.mtest_command + ['--no-suite', 'subprjsucc:fail'])
        self.assertFailedTestCount(3, self.mtest_command + ['--no-suite', 'subprjsucc:success'])

        self.assertFailedTestCount(1, self.mtest_command + ['--suite', 'subprjmix:fail'])
        self.assertFailedTestCount(0, self.mtest_command + ['--suite', 'subprjmix:success'])
        self.assertFailedTestCount(2, self.mtest_command + ['--no-suite', 'subprjmix:fail'])
        self.assertFailedTestCount(3, self.mtest_command + ['--no-suite', 'subprjmix:success'])

        self.assertFailedTestCount(2, self.mtest_command + ['--suite', 'subprjfail', '--suite', 'subprjmix:fail'])
        self.assertFailedTestCount(3, self.mtest_command + ['--suite', 'subprjfail', '--suite', 'subprjmix', '--suite', 'mainprj'])
        self.assertFailedTestCount(2, self.mtest_command + ['--suite', 'subprjfail', '--suite', 'subprjmix', '--suite', 'mainprj', '--no-suite', 'subprjmix:fail'])
        self.assertFailedTestCount(1, self.mtest_command + ['--suite', 'subprjfail', '--suite', 'subprjmix', '--suite', 'mainprj', '--no-suite', 'subprjmix:fail', 'mainprj-failing_test'])

        self.assertFailedTestCount(1, self.mtest_command + ['--no-suite', 'subprjfail:fail', '--no-suite', 'subprjmix:fail'])

    def _test_stds_impl(self, testdir, compiler, p):
        lang_std = p + '_std'
        # Check that all the listed -std=xxx options for this compiler work
        # just fine when used
        for v in compiler.get_options()[lang_std].choices:
            std_opt = '{}={}'.format(lang_std, v)
            self.init(testdir, ['-D' + std_opt])
            cmd = self.get_compdb()[0]['command']
            if v != 'none':
                cmd_std = "'-std={}'".format(v)
                self.assertIn(cmd_std, cmd)
            try:
                self.build()
            except:
                print('{} was {!r}'.format(lang_std, v))
                raise
            self.wipe()
        # Check that an invalid std option in CFLAGS/CPPFLAGS fails
        # Needed because by default ICC ignores invalid options
        cmd_std = '-std=FAIL'
        env_flags = p.upper() + 'FLAGS'
        os.environ[env_flags] = cmd_std
        self.init(testdir)
        cmd = self.get_compdb()[0]['command']
        qcmd_std = "'{}'".format(cmd_std)
        self.assertIn(qcmd_std, cmd)
        with self.assertRaises(subprocess.CalledProcessError,
                               msg='{} should have failed'.format(qcmd_std)):
            self.build()

    def test_compiler_c_stds(self):
        '''
        Test that C stds specified for this compiler can all be used. Can't be
        an ordinary test because it requires passing options to meson.
        '''
        testdir = os.path.join(self.common_test_dir, '1 trivial')
        env = Environment(testdir, self.builddir, self.meson_command,
                          get_fake_options(self.prefix), [])
        cc = env.detect_c_compiler(False)
        self._test_stds_impl(testdir, cc, 'c')

    def test_compiler_cpp_stds(self):
        '''
        Test that C++ stds specified for this compiler can all be used. Can't
        be an ordinary test because it requires passing options to meson.
        '''
        testdir = os.path.join(self.common_test_dir, '2 cpp')
        env = Environment(testdir, self.builddir, self.meson_command,
                          get_fake_options(self.prefix), [])
        cpp = env.detect_cpp_compiler(False)
        self._test_stds_impl(testdir, cpp, 'cpp')

    def test_build_by_default(self):
        testdir = os.path.join(self.unit_test_dir, '5 build by default')
        self.init(testdir)
        self.build()
        genfile = os.path.join(self.builddir, 'generated.dat')
        exe = os.path.join(self.builddir, 'fooprog')
        self.assertTrue(os.path.exists(genfile))
        self.assertFalse(os.path.exists(exe))
        self._run(self.ninja_command + ['fooprog'])
        self.assertTrue(os.path.exists(exe))

    def test_libdir_must_be_inside_prefix(self):
        testdir = os.path.join(self.common_test_dir, '1 trivial')
        # libdir being inside prefix is ok
        args = ['--prefix', '/opt', '--libdir', '/opt/lib32']
        self.init(testdir, args)
        self.wipe()
        # libdir not being inside prefix is not ok
        args = ['--prefix', '/usr', '--libdir', '/opt/lib32']
        self.assertRaises(subprocess.CalledProcessError, self.init, testdir, args)
        self.wipe()
        # libdir must be inside prefix even when set via mesonconf
        self.init(testdir)
        self.assertRaises(subprocess.CalledProcessError, self.setconf, '-Dlibdir=/opt')


class RewriterTests(unittest.TestCase):

    def setUp(self):
        super().setUp()
        src_root = os.path.dirname(__file__)
        self.testroot = tempfile.mkdtemp()
        self.rewrite_command = [sys.executable, os.path.join(src_root, 'mesonrewriter.py')]
        self.tmpdir = tempfile.mkdtemp()
        self.workdir = os.path.join(self.tmpdir, 'foo')
        self.test_dir = os.path.join(src_root, 'test cases/rewrite')

    def tearDown(self):
        shutil.rmtree(self.tmpdir)

    def read_contents(self, fname):
        with open(os.path.join(self.workdir, fname)) as f:
            return f.read()

    def check_effectively_same(self, mainfile, truth):
        mf = self.read_contents(mainfile)
        t = self.read_contents(truth)
        # Rewriting is not guaranteed to do a perfect job of
        # maintaining whitespace.
        self.assertEqual(mf.replace(' ', ''), t.replace(' ', ''))

    def prime(self, dirname):
        shutil.copytree(os.path.join(self.test_dir, dirname), self.workdir)

    def test_basic(self):
        self.prime('1 basic')
        subprocess.check_output(self.rewrite_command + ['remove',
                                                        '--target=trivialprog',
                                                        '--filename=notthere.c',
                                                        '--sourcedir', self.workdir])
        self.check_effectively_same('meson.build', 'removed.txt')
        subprocess.check_output(self.rewrite_command + ['add',
                                                        '--target=trivialprog',
                                                        '--filename=notthere.c',
                                                        '--sourcedir', self.workdir])
        self.check_effectively_same('meson.build', 'added.txt')
        subprocess.check_output(self.rewrite_command + ['remove',
                                                        '--target=trivialprog',
                                                        '--filename=notthere.c',
                                                        '--sourcedir', self.workdir])
        self.check_effectively_same('meson.build', 'removed.txt')

    def test_subdir(self):
        self.prime('2 subdirs')
        top = self.read_contents('meson.build')
        s2 = self.read_contents('sub2/meson.build')
        subprocess.check_output(self.rewrite_command + ['remove',
                                                        '--target=something',
                                                        '--filename=second.c',
                                                        '--sourcedir', self.workdir])
        self.check_effectively_same('sub1/meson.build', 'sub1/after.txt')
        self.assertEqual(top, self.read_contents('meson.build'))
        self.assertEqual(s2, self.read_contents('sub2/meson.build'))


if __name__ == '__main__':
    unittest.main()