C#: Add flow test cases for undetected value flow, when making variable bindings in pattern matching.

[michaelnebel]

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[tamasvajk]

A while back I also collected some unhandled tuple related patterns, but I never actually got to merging it: #5429. Maybe we could merge these efforts now.

Also, I think your test file shouldn't be in the library-tests/dataflow/fields/ folder. Maybe a new records folder would be more appropriate.

[michaelnebel]

That is a good point!
Not sure, what the best strategy is for structuring the tests.
Even though records are used here (it could just as well had been classes or structs), it is only the case, because it was the shortest form of type declarations I could think of, where we could make use of pattern matching with property patterns and variable bindings.
Maybe we need a folder pattern for all pattern related tests instead of scattering them across the other test topics?

[michaelnebel]

Should we just stick to the existing strategy?
Then I will create a records folder and move the pattern test here.

[tamasvajk]

Should we just stick to the existing strategy? Then I will create a records folder and move the pattern test here.

I don't know if there's an explicit existing strategy here. The field folder seems to contain tests for flows through fields. So these pattern related tests don't seem to belong there. We could add them to the local folder, or to a new pattern folder. I would probably go with the latter just to be explicit. (Although the tuples folder already contains test cases with pattern matching.) What do you think @hvitved?

[hvitved]

Let's add this to a new patterns folder (along with a new test).