Filtering: filter field type

This rule enforces that the field used for filtering, called filter, is of type string, as mandated by AIP-160.

Details

This rule looks at the request message for List methods and custom methods. Then, it verifes that any field called filter is of type string.

Examples

Incorrect code for this rule:

// Incorrect.
rpc ListBooks(ListBooksRequest) returns (ListBooksResponse) {
  bytes filter = 1;
}

// Incorrect.
rpc CheckoutBook(CheckoutBookRequest) returns (CheckoutBookResponse) {
  BookFilters filter = 1;

  message BookFilters {
    string publisher = 1;
    repeated string authors = 2;
  }
}

Correct code for this rule:

// Correct.
rpc ListBooks(ListBooksRequest) returns (ListBooksResponse) {
  string filter = 1;
}

// Correct.
rpc CheckoutBook(CheckoutBookRequest) returns (CheckoutBookResponse) {
  string filter = 1;
}

Disabling

If you need to violate this rule, use a leading comment above the method. Remember to also include an aip.dev/not-precedent comment explaining why.

// (-- api-linter: core::0160::filter-field-type=disabled
//     aip.dev/not-precedent: We need to do this because reasons. --)
rpc ListBooks(ListBooksRequest) returns (ListBooksResponse) {
  bytes filter = 1;
}

If you need to violate this rule for an entire file, place the comment at the top of the file.