Custom ISearchBinder does not support deeply nested $expand queries or single item queries

[WanjohiSammy]

Assemblies affected
7.x and 8.x

Describe the bug
The ISearchBinder fails to handle deeply nested $expand queries or single item queries such as customers(1) or Customers/1. For example:

• /Customers(1)?search=NOT (sam OR zz)
• /Customers?expand=Orders(expand=Products(search=snack))

These queries do not filter data based on the provided search terms, unlike simpler queries such as /Customers?search=NOT (sam OR zz) which work as expected.

For more details, refer to the DevBlog.

Reproduce steps

1. Clone the repository.

   git clone https://github.com/WanjohiSammy/ISearchBinderIssueWithSomeQueries.git

2. Build and run the application.
3. Test the following requests:
   • /Customers?search=NOT (sam OR zz) - Works as expected.
   • /Customers(6)?search=NOT (sam OR zz) - Returns everything. The custom ISearchBinder is not being triggered.
   • /Customers?expand=Orders(expand=Products(search=snack)) - Returns everything. The custom ISearchBinder is not being triggered.
   • /Customers(1)?expand=Orders(expand=Products(search=snack)) - Returns everything. The custom ISearchBinder is not being triggered.

Data Model
Please share your Data model, for example, your C# class.

EDM (CSDL) Model
Please share your Edm model, for example, CSDL file.
You can send $metadata to get a CSDL XML content.

Request/Response

• Request URIs:

  • /Customers?search=NOT (sam OR zz)
  • /Customers(6)?search=NOT (sam OR zz)
  • /Customers?expand=Orders(expand=Products(search=snack))
  • /Customers(1)?expand=Orders(expand=Products(search=snack))

• Expected Responses:
  Queries with $expand or single item queries should correctly filter data based on the search terms.

Expected behavior
Queries involving deeply nested $expand or single item queries should function correctly, similar to how /Customers?search=NOT (sam OR zz) behaves.

Screenshots
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Additional context
Please share your call stack or any error message
Add any other context about the problem here.

[xuzhg]

To be clear,

1. There's no 'default' implementation of ISearchBinder. Developer can implement his own logic by inject the implementation into the DI.
2. If there's a ISearchBinder implementation, it typically translates the search clause into Where(...) Linq Expression. And It only applies to collection, not for a single entity. That's why customers(1)?search=NOT (sam OR zz) doesn't apply.
3. for Nested Search, It seems this method (https://github.com/OData/AspNetCoreOData/blob/main/src/Microsoft.AspNetCore.OData/Query/Expressions/SelectExpandBinder.cs#L196) should accept the nested Search and bind the search into account if there's a 'ISearchBinder' implemented. It's a gap that we will fill out later.