Etag field type

This rule enforces that etag fields are strings, as mandated in AIP-154.

Details

This rule looks at any field named etag and complains if the type is anything other than string.

Examples

Incorrect code for this rule:

// Incorrect.
message DeleteBookRequest {
  string name = 1 [(google.api.resource_reference) = {
    type: "library.googleapis.com/Book"
  }];
  bytes etag = 2;  // Should be string.
}

Correct code for this rule:

// Correct.
message DeleteBookRequest {
  string name = 1 [(google.api.resource_reference) = {
    type: "library.googleapis.com/Book"
  }];
  string etag = 2;
}

Disabling

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

message DeleteBookRequest {
  string name = 1 [(google.api.resource_reference) = {
    type: "library.googleapis.com/Book"
  }];
  // (-- api-linter: core::0154::field-type=disabled
  //     aip.dev/not-precedent: We need to do this because reasons. --)
  bytes etag = 2;
}

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