Remove Mechanical Markdown from examples/ validation

[seherv]

Description

Removes all references to Mechanical Markdown and replaces them with pytest files that validate the output generated by the examples.

Tests are still flaky and rely on exact log output, which is not ideal. This will be addressed in a future PR.

Issue reference

We strive to have all PR being opened based on an issue, where the problem or feature have been discussed prior to implementation.

Please reference the issue this PR will close: #972 (first iteration, do not close the issue yet)

Checklist

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• Code compiles correctly
• Created/updated tests
• Extended the documentation

[Copilot]

Pull request overview

This PR migrates example validation away from Mechanical Markdown to pytest-based integration tests, so the examples/ directory is validated via native Python tests that run the examples and assert on their output.

Changes:

• Replaces the tox -e examples Mechanical Markdown workflow with a new tox -e integration pytest environment.
• Adds tests/integration/ with a DaprRunner helper + one pytest file per example to validate expected output.
• Updates project docs (README.md, AGENTS.md, examples/AGENTS.md) and removes examples/validate.sh.

Reviewed changes

Copilot reviewed 29 out of 29 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tox.ini	Removes Mechanical Markdown example envs and adds integration env running pytest.
pyproject.toml	Registers the custom example_dir pytest marker.
README.md	Updates developer instructions to run tox -e integration.
AGENTS.md	Updates repo contributor guidance to refer to pytest integration tests instead of Mechanical Markdown.
examples/AGENTS.md	Rewrites examples validation docs to describe pytest/DaprRunner approach.
examples/validate.sh	Removes the Mechanical Markdown validation entrypoint script.
CLAUDE.md	Adds repository development guidelines.
tests/integration/conftest.py	Introduces DaprRunner, output assertion helper, and dapr fixture/marker handling.
tests/integration/test_workflow.py	Adds integration coverage for the workflow examples (task chaining, fan-out/fan-in, simple).
tests/integration/test_w3c_tracing.py	Adds integration coverage for w3c tracing example with background receiver.
tests/integration/test_state_store.py	Adds integration coverage for state store example output.
tests/integration/test_state_store_query.py	Adds integration coverage for state store query example with MongoDB setup.
tests/integration/test_secret_store.py	Adds integration coverage for secret store example (with/without ACL config).
tests/integration/test_pubsub_streaming.py	Adds integration coverage for streaming pubsub example (subscriber/publisher).
tests/integration/test_pubsub_streaming_async.py	Adds integration coverage for async streaming pubsub example (subscriber/publisher).
tests/integration/test_pubsub_simple.py	Adds integration coverage for basic pubsub example (subscriber/publisher).
tests/integration/test_metadata.py	Adds integration coverage for metadata example output.
tests/integration/test_langgraph_checkpointer.py	Adds integration coverage for langgraph checkpointer example (skips if deps missing).
tests/integration/test_jobs.py	Adds integration coverage for jobs example (management + processing).
tests/integration/test_invoke_simple.py	Adds integration coverage for invoke-simple using direct sidecar HTTP call to avoid infinite loop.
tests/integration/test_invoke_custom_data.py	Adds integration coverage for invoke-custom-data (receiver + caller).
tests/integration/test_invoke_binding.py	Adds integration coverage for invoke-binding with Kafka docker-compose setup.
tests/integration/test_grpc_proxying.py	Adds integration coverage for gRPC proxying example (receiver + caller).
tests/integration/test_error_handling.py	Adds integration coverage for error handling example output.
tests/integration/test_distributed_lock.py	Adds integration coverage for distributed lock example output.
tests/integration/test_demo_actor.py	Adds integration coverage for demo actor example (service + client).
tests/integration/test_crypto.py	Adds integration coverage for crypto examples with key generation/cleanup fixture.
tests/integration/test_conversation.py	Adds integration coverage for conversation examples output.
tests/integration/test_configuration.py	Adds integration coverage for configuration example with Redis seeding + update trigger.

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[Copilot]

The PR renames/removes the examples tox env, but CI still runs tox -e examples (e.g., .github/workflows/validate_examples.yaml:156). As-is, the workflow will fail with “unknown environment” unless the workflow is updated or an alias testenv:examples is kept for backward compatibility.

[Copilot]

Importing assert_lines_in_output via from conftest import ... will fail when running pytest from the repo root (because tests/integration/conftest.py isn’t importable as a top-level module). Prefer moving the helper into a regular module (e.g., tests/integration/utils.py) and importing from there, or avoid importing it altogether and keep the assertion helper local to this test file.

Suggested change

	from conftest import assert_lines_in_output
	def assert_lines_in_output(output, expected_lines, ordered=False):
	if ordered:
	start = 0
	for expected_line in expected_lines:
	index = output.find(expected_line, start)
	assert index != -1, (
	f"Expected line not found in order: {expected_line!r}\n\nOutput was:\n{output}"
	)
	start = index + len(expected_line)
	else:
	for expected_line in expected_lines:
	assert expected_line in output, (
	f"Expected line not found: {expected_line!r}\n\nOutput was:\n{output}"
	)

[Copilot]

stop() assumes the stdout-draining thread has finished, but it only join()s with a timeout. If the thread is still alive after 5s, later self._bg_lines = [] can cause the still-running thread to append into the new list (contaminating subsequent test output) and/or truncate output returned by stop(). Consider joining without a timeout (or verifying the thread exited) before clearing state.

[Copilot]

cleanup() has the same issue as stop(): it join()s the reader thread with a timeout and then resets internal state. If the reader thread hasn’t actually exited yet, it can append to self._bg_lines after it has been reset. Consider joining without a timeout (or otherwise guaranteeing the reader has stopped) before clearing state.

[Copilot]

urllib.request.urlopen(req) is called without closing/reading the response body. Using a context manager (and consuming the body) avoids leaking sockets/file descriptors and suppresses ResourceWarning noise in test output, especially if this loop grows.

Suggested change

	urllib.request.urlopen(req)
	with urllib.request.urlopen(req) as response:
	response.read()