Specify dependency of each test case

まず、テストメソッドと既存の array_helpers およびモジュールスタブ機構を確認します。次に、pytest の collection hook と、テストスイートがトップレベル関数、配列オブジェクトのメソッド、演算子をどのように表現しているかを調査します。完了時には、定義された依存関係表現、依存関係グラフ、依存関係を考慮したテストの優先順位付けまたはスキップを含める必要があります。

The test suite is mostly made up of test methods for each function (or array object method) in the spec. The majority of these tests require other functions to do everything we want, which is problematic when an underlying function does not work—you'll get a lot of spammy errors that actually relate to a single fundamental problem... or even false positives.

So I think it would be a good idea if we declared the dependencies of each test method, i.e. the functions we use and assume has correct behaviour. We could use these declarations to create a dependency graph, which could be hooked with pytest to prioritise zero/low-dependency tests first, and by default skipping tests that use functions we've deemed incorrect. This will benefit:

1. Array API adoptors, who would much more easily see what they should prioritise developing
2. Us, who'd be able to see areas where we can try to cut down the functions we depend on

Ideas for declaring dependencies per test method:

• Decorator which lists function and method names
• Automatically infer dependencies via looking at function code (either searching the code as string, or using the AST)

General challenges would be:

• How to get pytests collection hook to do this
• Supporting array object methods alongside the top-level functions
  • As well as operator symbols

The dependency graph + auto skipping would also allow us to:

• Remove some mirrored functions in array_helpers
• Remove the module stubbing mechanism
• Check that no tests is using the function they're testing for assertions