test: replace subprocess calls with run_example_module helper (#7)

Author: JakubAndrysek

tests/test_hello_esp32.py

@@ -2,25 +2,11 @@
 #
 # SPDX-License-Identifier: MIT
 
-import os
-import subprocess
-import sys
+from .utils import run_example_module
 
 
 def test_hello_esp32_example() -> None:
-    """`python -m examples.hello_esp32.main` runs the hello_esp32 example and exits with 0."""
-
-    assert os.environ.get("WOKWI_CLI_TOKEN") is not None, (
-        "WOKWI_CLI_TOKEN environment variable is not set. You can get it from https://wokwi.com/dashboard/ci."
-    )
-
-    result = subprocess.run(
-        [sys.executable, "-m", "examples.hello_esp32.main"],
-        check=False,
-        capture_output=True,
-        text=True,
-        env={**os.environ, "WOKWI_SLEEP_TIME": "1"},
-    )
-
+    """Async hello_esp32 example should run and exit with 0."""
+    result = run_example_module("examples.hello_esp32.main")
     assert result.returncode == 0
     assert "main_task: Calling app_main()" in result.stdout

tests/test_micropython_esp32.py

@@ -0,0 +1,14 @@
+# SPDX-FileCopyrightText: 2025-present CodeMagic LTD
+#
+# SPDX-License-Identifier: MIT
+
+from .utils import run_example_module
+
+
+def test_micropython_esp32_example() -> None:
+    """MicroPython ESP32 example should run and print MicroPython banner."""
+    # MicroPython boot can take a bit longer; give it a few seconds
+    result = run_example_module("examples.micropython_esp32.main", sleep_time="3")
+    assert result.returncode == 0
+    # Expect a line from the injected MicroPython script
+    assert "Hello, MicroPython! I'm running on a Wokwi ESP32 simulator." in result.stdout

tests/utils.py

@@ -0,0 +1,40 @@
+"""
+Test utilities for running example modules.
+
+Provides a helper to execute `python -m <module>` with a short sleep to keep
+CI fast and shared environment handling (WOKWI_CLI_TOKEN, etc.).
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+from collections.abc import Mapping
+from subprocess import CompletedProcess
+
+
+def run_example_module(
+    module: str, *, sleep_time: str = "1", extra_env: Mapping[str, str] | None = None
+) -> CompletedProcess[str]:
+    """Run an example module with a short simulation time.
+
+    Requires WOKWI_CLI_TOKEN to be set in the environment.
+    Returns the CompletedProcess so tests can assert on return code and output.
+    """
+
+    assert os.environ.get("WOKWI_CLI_TOKEN") is not None, (
+        "WOKWI_CLI_TOKEN environment variable is not set. You can get it from https://wokwi.com/dashboard/ci."
+    )
+
+    env = {**os.environ, "WOKWI_SLEEP_TIME": sleep_time}
+    if extra_env:
+        env.update(extra_env)
+
+    return subprocess.run(
+        [sys.executable, "-m", module],
+        check=False,
+        capture_output=True,
+        text=True,
+        env=env,
+    )