Add behavior tests for Sensors API and replace brittle source-string assertion

[bhudevbhanpuriya]

Description

The current test coverage gives false confidence around API behavior.

There are no direct tests for the Sensors endpoints in api/tests, so regressions in GET /Sensors, POST /Sensors, PATCH /Sensors(id), or DELETE /Sensors(id) may not be caught.

Additionally, api/tests/test_update_user_error_message.py checks the contents of api/app/v1/endpoints/update/user.py as plain text instead of testing runtime behavior. For example, it asserts that certain source strings exist:

self.assertIn('except UndefinedObjectError as e:', content)
self.assertIn('content={"message": "User not found"}', content)
This is brittle because formatting or refactoring can break the test even if behavior is correct. It can also pass even if the endpoint behavior is wrong.

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Understanding the problem

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Expected Behavior

Tests should verify actual API/endpoint behavior, not source-code strings.

Proposed Fix

• Add endpoint-level tests for Sensors API behavior:

  • GET /Sensors returns a streaming response when data exists.
  • GET /Sensors returns 404 when no rows are found.
  • POST /Sensors validates JSON content type.
  • POST /Sensors returns a Location header after creation.
  • PATCH /Sensors(id) returns 404 for a missing sensor.
  • DELETE /Sensors(id) returns 404 for a missing sensor.

• Rewrite test_update_user_error_message.py to call update_user() directly and assert the actual response.

• Ensure api/tests is included in default pytest collection.

Why This Matters

Behavior tests protect the public API contract. Source-string tests only protect implementation details and can miss real regressions.

Acceptance Criteria

• Sensors endpoints have direct behavior coverage in api/tests.
• test_update_user_error_message.py no longer reads endpoint source files.
• Default pytest collection includes api/tests.
• Tests can run without requiring a live database by mocking DB pools and endpoint collaborators.