fix(tests): Resolve caio context leak causing EAGAIN on CI

[Cristhianzl]

Objective

Fix persistent SystemError: (11, 'Resource temporarily unavailable') in test_get_project_data on Linux CI caused by aiofile/caio async I/O context accumulation.

Changes

• Replace aiofile.async_open() with anyio.Path.read_text() in load_starter_projects() to eliminate caio context leak
• Add regression test test_should_not_leak_caio_contexts_when_loading_starter_projects that asserts zero caio context growth
• Fix unawaited coroutine warnings in Ollama mock tests by replacing AsyncMock().raise_for_status with MagicMock(return_value=None)

Summary by CodeRabbit

• Bug Fixes

  • Improved robustness of starter projects loading with automatic retry logic on failures, ensuring more reliable initialization.
  • Fixed potential context leak issues that could occur during startup on Linux CI environments.

• Tests

  • Enhanced test coverage to prevent context leak regressions during startup processes.

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Walkthrough

Replaces async file reading with synchronous read_text() and adds retry logic for JSON parsing failures in the setup module, standardizes HTTP mock configurations across multiple test files using MagicMock wrappers, and adds a new test to detect context leaks during startup project loading.

Changes

Cohort / File(s)	Summary
Setup Module Updates src/backend/base/langflow/initial_setup/setup.py	Replaces async file reading with synchronous read_text(encoding="utf-8"), implements retry logic with configurable retries and delays for JSON decode failures, and raises ValueError on exhausted retries while maintaining existing logging behavior.
Test Mock Configuration Standardization src/backend/tests/unit/components/embeddings/test_ollama_embeddings_component.py, src/backend/tests/unit/components/languagemodels/test_chatollama_component.py	Updates mock object configurations across HTTP response mocks by replacing mock_object.raise_for_status.return_value = None assignments with mock_object.raise_for_status = MagicMock(return_value=None) to properly wrap the method as a callable MagicMock.
Initial Setup Tests src/backend/tests/unit/test_initial_setup.py	Adds new async test test_should_not_leak_caio_contexts_when_loading_starter_projects() that verifies load_starter_projects() does not leak caio AsyncioContext instances by measuring context store state before and after execution.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

🚥 Pre-merge checks | ✅ 6 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Test Quality And Coverage	⚠️ Warning	Test suite for load_starter_projects() lacks coverage of retry logic, error handling, and JSON decode failures; only happy path and regression test present.	Add tests for retry behavior, JSON decode errors, delay timing, exhausted retries, and edge cases using mocks and @pytest.mark.asyncio decorators.

✅ Passed checks (6 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically addresses the main objective: fixing a caio context leak causing EAGAIN errors on CI by replacing aiofile with anyio and adding a regression test.
Docstring Coverage	✅ Passed	Docstring coverage is 82.61% which is sufficient. The required threshold is 80.00%.
Test Coverage For New Implementations	✅ Passed	PR adds regression test test_should_not_leak_caio_contexts_when_loading_starter_projects() to verify the bug fix for context leaks in load_starter_projects(). Test is properly located in src/backend/tests/unit/test_initial_setup.py with correct naming conventions and includes actual assertions.
Test File Naming And Structure	✅ Passed	All test files follow test_*.py naming pattern, use descriptive test function names, implement proper pytest structure with appropriate imports and decorators, and are logically organized.
Excessive Mock Usage Warning	✅ Passed	Test files appropriately mock only external dependencies while testing real component behavior; PR changes simplify mock configuration and improve quality without introducing excessive mocking.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch cz/fix-load-starter-projects

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[codecov]

Codecov Report

❌ Patch coverage is 78.26087% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 35.73%. Comparing base (655aee4) to head (edb9c49).
⚠️ Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
src/backend/base/langflow/api/v2/mcp.py	77.27%	5 Missing ⚠️

❌ Your project status has failed because the head coverage (42.40%) is below the target coverage (60.00%). You can increase the head coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #11936      +/-   ##
==========================================
+ Coverage   35.71%   35.73%   +0.01%     
==========================================
  Files        1528     1528              
  Lines       73928    73958      +30     
  Branches    11134    11154      +20     
==========================================
+ Hits        26407    26427      +20     
- Misses      46081    46093      +12     
+ Partials     1440     1438       -2     

Flag	Coverage Δ
backend	56.39% <78.26%> (+0.08%)	⬆️
frontend	17.18% <ø> (-0.01%)	⬇️
lfx	42.40% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/backend/base/langflow/initial_setup/setup.py	52.30% <100.00%> (-0.07%)	⬇️
src/backend/base/langflow/api/v2/mcp.py	51.00% <77.27%> (-0.33%)	⬇️

... and 25 files with indirect coverage changes

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[github-actions]

Frontend Unit Test Coverage Report

Coverage Summary

Lines	Statements	Branches	Functions
	18.98% (6167/32488)	12.5% (3176/25389)	12.68% (884/6969)

Unit Test Results

Tests	Skipped	Failures	Errors	Time
2346	0 💤	0 ❌	0 🔥	33.91s ⏱️