Strengthen tidy3d-extras packaging test

[caseyflex]

Some minor improvements to packaging:

• disable_local_subpixel should restore the config even if the function it wraps errors
• check if the module exists before trying to import it, to discriminate between different types of import errors
• a bit better error messages

Greptile Overview

Updated On: 2025-10-10 17:41:16 UTC

Greptile Summary

This PR strengthens the packaging system for the optional tidy3d-extras dependency by improving error handling and module detection logic. The changes refactor the supports_local_subpixel decorator in tidy3d/packaging.py to use find_spec() for more robust module existence checking before attempting imports, providing clearer error differentiation between "module not found" vs "module failed to initialize". The disable_local_subpixel decorator is also enhanced with proper try/finally blocks to ensure configuration state is always restored even when exceptions occur.

Additionally, a new test function test_tidy3d_extras() is added to tests/test_components/test_packaging.py that validates the packaging behavior for both scenarios when tidy3d-extras is available and when it's not. This test ensures that the @supports_local_subpixel decorator correctly detects the module, loads features, and sets appropriate flags. The changes improve the reliability of Tidy3D's optional dependency handling, which is critical for a library that extends core functionality through optional packages.

Important Files Changed

Changed Files

Filename	Score	Overview
tidy3d/packaging.py	4/5	Refactored module detection logic using find_spec() and improved error handling with try/finally blocks
tests/test_components/test_packaging.py	4/5	Added comprehensive test for tidy3d-extras packaging functionality and module detection

Confidence score: 4/5

• This PR improves robustness of optional dependency handling with minimal risk of breaking existing functionality
• Score reflects solid improvements to error handling and testing coverage, but complexity in module loading logic requires careful review
• Pay close attention to the refactored supports_local_subpixel decorator logic in tidy3d/packaging.py

Sequence Diagram

sequenceDiagram
    participant User
    participant test_tidy3d_extras
    participant importlib
    participant supports_local_subpixel
    participant get_eps
    participant tidy3d_extras_global
    participant config
    participant tidy3d_extras_mod

    User->>test_tidy3d_extras: "Run test_tidy3d_extras()"
    test_tidy3d_extras->>importlib: "find_spec('tidy3d_extras')"
    importlib-->>test_tidy3d_extras: "spec or None"
    test_tidy3d_extras->>test_tidy3d_extras: "has_tidy3d_extras = spec is not None"
    test_tidy3d_extras->>get_eps: "@supports_local_subpixel decorated call"
    
    supports_local_subpixel->>config: "Check config.use_local_subpixel"
    
    alt config.use_local_subpixel is False
        supports_local_subpixel->>tidy3d_extras_global: "Set use_local_subpixel = False"
        supports_local_subpixel->>tidy3d_extras_global: "Set mod = None"
    else config.use_local_subpixel is not False and mod is None
        supports_local_subpixel->>tidy3d_extras_global: "Set use_local_subpixel = False"
        supports_local_subpixel->>importlib: "find_spec('tidy3d_extras')"
        importlib-->>supports_local_subpixel: "spec or None"
        
        alt module exists
            supports_local_subpixel->>tidy3d_extras_mod: "import tidy3d_extras"
            tidy3d_extras_mod-->>supports_local_subpixel: "tidy3d_extras_mod"
            supports_local_subpixel->>tidy3d_extras_mod: "Check __version__"
            supports_local_subpixel->>tidy3d_extras_mod: "extension._features()"
            tidy3d_extras_mod-->>supports_local_subpixel: "features list"
            supports_local_subpixel->>tidy3d_extras_global: "Set mod = tidy3d_extras_mod"
            supports_local_subpixel->>tidy3d_extras_global: "Set use_local_subpixel = 'local_subpixel' in features"
        end
    end
    
    supports_local_subpixel->>get_eps: "Call original function"
    
    alt has_tidy3d_extras is True
        get_eps->>tidy3d_extras_global: "Assert mod is not None"
        get_eps->>tidy3d_extras_global: "Get mod.extension._features()"
        get_eps->>get_eps: "Assert use_local_subpixel == ('local_subpixel' in features)"
    else has_tidy3d_extras is False
        get_eps->>tidy3d_extras_global: "Assert use_local_subpixel is False"
        get_eps->>tidy3d_extras_global: "Assert mod is None"
    end
    
    get_eps-->>test_tidy3d_extras: "Function execution complete"
    test_tidy3d_extras-->>User: "Test complete"

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[greptile-apps]

Additional Comments (2)

1. tests/test_components/test_packaging.py, line 79 (link)

   style: Consider removing this print statement as it's debug output that shouldn't be in production tests

   Context Used: Rule from dashboard - Remove temporary debugging code (print() calls), commented-out code, and other workarounds before fi... (source)

2. tests/test_components/test_packaging.py, line 5 (link)

   style: The config import is unused in this file - consider removing it if not needed

_{2 files reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[github-actions]

Diff Coverage

Diff: origin/develop...HEAD, staged and unstaged changes

• tidy3d/packaging.py (66.7%): Missing lines 201,209-210,212

Summary

• Total: 12 lines
• Missing: 4 lines
• Coverage: 66%

tidy3d/packaging.py

Lines 197-205

  197             if tidy3d_extras["mod"] is None:
  198                 tidy3d_extras["use_local_subpixel"] = False
  199                 module_exists = find_spec("tidy3d_extras") is not None
  200                 if config.use_local_subpixel is True and not module_exists:
! 201                     raise Tidy3dImportError(
  202                         "The package 'tidy3d-extras' is required for this "
  203                         "operation when 'config.use_local_subpixel' is 'True'. "
  204                         "Please install the 'tidy3d-extras' package using, for "
  205                         "example, 'pip install tidy3d[extras]'."

---

Lines 205-216

  205                         "example, 'pip install tidy3d[extras]'."
  206                     )
  207 
  208                 if module_exists:
! 209                     try:
! 210                         import tidy3d_extras as tidy3d_extras_mod
  211 
! 212                     except ImportError as exc:
  213                         # this should not happen; if the API key is invalid,
  214                         # the package should still import but the version will be None
  215                         raise Tidy3dImportError(
  216                             "The package 'tidy3d-extras' did not initialize correctly. "

---