Test plan for "collection expression arguments" feature

[jcouv]

Championed proposal: dotnet/csharplang#8887
Speclet: https://github.com/dotnet/csharplang/blob/main/proposals/collection-expression-arguments.md

Compiler:

• LangVer behavior
• order of evaluation
• ref analysis
• API review
• nullability analysis
• __arglist
• semantic model (GetSymbolInfo)
  • what is expected for GetMemberGroup?
• IOperation
• update compiler test plan
• update BindCollectionExpressionForErrorRecovery?
• with in params: M(with(A, B), C, D) (disallowed)
• constructor for type with required fields
• interpolation handlers
• Expression trees
• out var in with
• If you add a new expression that can be nested inside itself, test deeply nesting it. Potentially cut off direct nesting.
• Should collection arguments be included in IOperation tree? Issue about branches not showing in CFG

IDE:

• completion
• colorization
• QuickInfo
• formatting
• GoToDef on with
• signature/parameter info while typing in with

[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• Test plan for Dictionary Expressions #76310