Move DummyBackend to public openeo.testing module

[Copilot]

The DummyBackend testing utility was located in the private openeo.rest._testing module, preventing users from safely using it in their own tests without relying on internal APIs.

Changes

• Moved testing utilities to openeo/testing/backend.py

  • DummyBackend class
  • OpeneoTestingException
  • build_capabilities() function

• Updated openeo/testing/__init__.py to export the public API

• Converted openeo/rest/_testing.py to a backward compatibility wrapper that imports from the new location

  • Note: OPENEO_BACKEND constant remains in openeo/rest/_testing.py only (not moved to the public API as it's unrelated to DummyBackend)

• Moved tests to tests/testing/test_backend.py - Relocated DummyBackend tests from tests/rest/test_testing.py to align with the new module structure and updated imports to use the public API

Usage

Users can now import from the public module:

from openeo.testing import DummyBackend, build_capabilities

# Create a mock backend for testing
dummy = DummyBackend.at_url("https://test.example", requests_mock=requests_mock)
dummy.setup_collection("S2")

# Test your code against the mock
cube = dummy.connection.load_collection("S2")
cube.execute()

# Inspect the process graph
pg = dummy.get_sync_pg()

The old import path continues to work for backward compatibility, including access to OPENEO_BACKEND which remains available only from openeo.rest._testing.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Move DummyBackend to openeo.testing</issue_title>
<issue_description>this TODO:

openeo-python-client/openeo/rest/_testing.py

Lines 28 to 34 in 0cf3bdd

	class DummyBackend:
	"""
	Dummy backend that handles sync/batch execution requests
	and allows inspection of posted process graphs
	"""
	# TODO: move to openeo.testing

so users can use this for their own testing in a future proof manner

CC @soxofaan </issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Move DummyBackend to openeo.testing #762

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[soxofaan]

@copilot can you also move the DummyBackend tests accordingly?

[soxofaan]

@copilot don't move the OPENEO_BACKEND constant as it is unrelated to DummyBackend

[Copilot]

@copilot can you also move the DummyBackend tests accordingly?

Done! Moved the tests from tests/rest/test_testing.py to tests/testing/test_backend.py and updated the imports to use the new public API (from openeo.testing import DummyBackend). All 7 tests pass in the new location. (1bdee2d)

[Copilot]

@copilot don't move the OPENEO_BACKEND constant as it is unrelated to DummyBackend

Done! Removed OPENEO_BACKEND from openeo.testing and kept it in openeo.rest._testing where it was originally. It's now only available from the old import path for backward compatibility. (1b5ed26)