add a couple of the most basic tests using Pytest

I'm super-unsure about this; I don't really like all the magic, but
we'll see, I guess?

7 files changed, 264 insertions, 0 deletions

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
new file mode 100644
index 0000000..5d16f4e
--- /dev/null
+++ b/test/CMakeLists.txt
@@ -0,0 +1,11 @@
+find_package(Python3 REQUIRED COMPONENTS Interpreter)
+
+add_test(
+    NAME integration_tests
+    COMMAND Python3::Interpreter -m pytest
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+        --server-binary "$<TARGET_FILE:server>"
+        --worker-binary "$<TARGET_FILE:worker>"
+        --client-binary "$<TARGET_FILE:client>"
+        --project-version "${PROJECT_VERSION}"
+    WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
diff --git a/test/__init__.py b/test/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/__init__.py
diff --git a/test/conftest.py b/test/conftest.py
new file mode 100644
index 0000000..5f70bd5
--- /dev/null
+++ b/test/conftest.py
@@ -0,0 +1,128 @@
+# Copyright (c) 2023 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is part of the "cimple" project.
+# For details, see https://github.com/egor-tensin/cimple.
+# Distributed under the MIT License.
+
+import logging
+import os
+import random
+
+from pytest import fixture
+
+from .lib.process import run, run_async
+
+
+class CmdLineOption:
+    def __init__(self, codename, help_string):
+        self.codename = codename
+        self.help_string = help_string
+
+    @property
+    def cmd_line(self):
+        return f"--{self.codename.replace('_', '-')}"
+
+
+class CmdLineBinary(CmdLineOption):
+    def __init__(self, name):
+        self.name = name
+        super().__init__(self.get_code_name(), self.get_help_string())
+
+    def get_code_name(self):
+        return f'{self.name}_binary'
+
+    @property
+    def basename(self):
+        return f'cimple-{self.name}'
+
+    def get_help_string(self):
+        return f'{self.basename} binary path'
+
+
+CMD_LINE_BINARIES = [CmdLineBinary(name) for name in ('server', 'worker', 'client')]
+
+
+class CmdLineVersion(CmdLineOption):
+    def __init__(self):
+        super().__init__('project_version', 'project version')
+
+
+CMD_LINE_VERSION = CmdLineVersion()
+CMD_LINE_OPTIONS = CMD_LINE_BINARIES + [CMD_LINE_VERSION]
+
+
+def pytest_addoption(parser):
+    for opt in CMD_LINE_OPTIONS:
+        parser.addoption(opt.cmd_line, required=True, help=opt.help_string)
+
+
+def pytest_generate_tests(metafunc):
+    for opt in CMD_LINE_OPTIONS:
+        if opt.codename in metafunc.fixturenames:
+            metafunc.parametrize(opt.codename, metafunc.config.getoption(opt.codename))
+
+
+@fixture(scope='session')
+def rng():
+    random.seed()
+
+
+class Paths:
+    def __init__(self, pytestconfig):
+        for binary in CMD_LINE_BINARIES:
+            path = pytestconfig.getoption(binary.codename)
+            logging.info('%s path: %s', binary.basename, path)
+            setattr(self, binary.codename, path)
+
+
+@fixture
+def paths(pytestconfig):
+    return Paths(pytestconfig)
+
+
+@fixture
+def version(pytestconfig):
+    return pytestconfig.getoption(CMD_LINE_VERSION.codename)
+
+
+@fixture
+def server_port(rng):
+    return str(random.randint(2000, 50000))
+
+
+@fixture
+def sqlite_path(tmp_path):
+    return os.path.join(tmp_path, 'cimple.sqlite')
+
+
+@fixture
+def server(paths, server_port, sqlite_path):
+    with run_async(paths.server_binary, '--port', server_port, '--sqlite', sqlite_path) as server:
+        yield
+    assert server.returncode == 0
+
+
+@fixture
+def workers(paths, server_port):
+    args = [paths.worker_binary, '--host', '127.0.0.1', '--port', server_port]
+    with run_async(*args) as worker1, run_async(*args) as worker2:
+        yield
+    assert worker1.returncode == 0
+    assert worker2.returncode == 0
+
+
+@fixture
+def server_and_workers(server, workers):
+    yield
+
+
+class Client:
+    def __init__(self, binary):
+        self.binary = binary
+
+    def run(self, *args):
+        return run(self.binary, *args)
+
+
+@fixture
+def client(paths):
+    return Client(paths.client_binary)
diff --git a/test/lib/__init__.py b/test/lib/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/lib/__init__.py
diff --git a/test/lib/process.py b/test/lib/process.py
new file mode 100644
index 0000000..f757167
--- /dev/null
+++ b/test/lib/process.py
@@ -0,0 +1,104 @@
+# Copyright (c) 2023 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is part of the "cimple" project.
+# For details, see https://github.com/egor-tensin/cimple.
+# Distributed under the MIT License.
+
+from contextlib import contextmanager
+import logging
+import os
+import subprocess
+from threading import Thread
+import time
+
+
+_COMMON_ARGS = {
+    'text': True,
+    'stdin': subprocess.DEVNULL,
+    'stdout': subprocess.PIPE,
+    'stderr': subprocess.STDOUT,
+}
+
+
+def _canonicalize_process_args(binary, *args):
+    binary = os.path.abspath(binary)
+    argv = list(args)
+    argv = [binary] + argv
+    return binary, argv
+
+
+def _log_process_args(binary, argv):
+    if argv:
+        logging.info('Executing binary %s with arguments: %s', binary, ' '.join(argv[1:]))
+    else:
+        logging.info('Executing binary %s', binary)
+
+
+class LoggingThread(Thread):
+    def __init__(self, process):
+        self.process = process
+        target = lambda pipe: self.consume(pipe)
+        super().__init__(target=target, args=[process.stdout])
+
+    def consume(self, pipe):
+        for line in iter(pipe):
+            logging.info('%s: %s', self.process.log_id, line)
+
+    def __enter__(self):
+        self.start()
+        return self
+
+    def __exit__(self, *args):
+        self.process.shut_down()
+        self.join()
+
+
+class Process(subprocess.Popen):
+    def __init__(self, binary, *args):
+        binary, argv = _canonicalize_process_args(binary, *args)
+        _log_process_args(binary, argv)
+
+        self.binary = binary
+        self.name = os.path.basename(binary)
+
+        super().__init__(argv, **_COMMON_ARGS)
+        # TODO: figure out how to remove this.
+        time.sleep(1)
+        logging.info('Process %s launched', self.log_id)
+
+    @property
+    def log_id(self):
+        return f'{self.pid}/{self.name}'
+
+    def __exit__(self, *args):
+        try:
+            self.shut_down()
+        finally:
+            super().__exit__(*args)
+
+    def shut_down(self):
+        ec = self.poll()
+        if ec is not None:
+            return
+        logging.info('Terminating process %s', self.log_id)
+        self.terminate()
+        try:
+            self.wait(timeout=3)
+            return
+        except subprocess.TimeoutExpired:
+            pass
+        self.kill()
+        self.wait(timeout=3)
+
+
+@contextmanager
+def run_async(binary, *args):
+    with Process(binary, *args) as process, \
+         LoggingThread(process):
+        yield process
+
+
+def run(binary, *args):
+    binary, argv = _canonicalize_process_args(binary, *args)
+    _log_process_args(binary, argv)
+    result = subprocess.run(argv, **_COMMON_ARGS)
+    return result.returncode, result.stdout
diff --git a/test/pytest.ini b/test/pytest.ini
new file mode 100644
index 0000000..cdc0831
--- /dev/null
+++ b/test/pytest.ini
@@ -0,0 +1,5 @@
+[pytest]
+log_format = %(asctime)s | %(levelname)s | %(message)s
+log_date_format = %Y-%m-%d %H:%M:%S
+log_cli_level = INFO
+#log_cli = 1
diff --git a/test/test_basic.py b/test/test_basic.py
new file mode 100644
index 0000000..b072384
--- /dev/null
+++ b/test/test_basic.py
@@ -0,0 +1,16 @@
+# Copyright (c) 2023 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is part of the "cimple" project.
+# For details, see https://github.com/egor-tensin/cimple.
+# Distributed under the MIT License.
+
+import pytest
+
+
+def test_server_and_workers_run(server_and_workers):
+    pass
+
+
+def test_client_version(client, version):
+    ec, output = client.run('--version')
+    assert ec == 0
+    assert output.endswith(version + '\n')