Resource name components alternate

This rule enforces that messages that have a google.api.resource annotation have pattern annotations that alternate between collection and identifier, as described in AIP-123.

Details

This rule scans messages with a google.api.resource annotation, and validates that each pattern alternated between collection and identifiers.

Examples

Incorrect code for this rule:

// Incorrect.
message Book {
  option (google.api.resource) = {
    type: "library.googleapis.com/Book"
    // two collections next to each other.
    pattern: "publishers/books/{book}"
  };
  string name = 1;
}

Correct code for this rule:

// Correct.
message Book {
  option (google.api.resource) = {
    type: "library.googleapis.com/Book"
    pattern: "publishers/{publisher}/books/{book}"
  };
  string name = 1;
}

Disabling

If you need to violate this rule, use a leading comment above the message.

// (-- api-linter: core::0123::resource-name-components-alternate=disabled
//     aip.dev/not-precedent: We need to do this because reasons. --)
message Book {
  option (google.api.resource) = {
    type: "library.googleapis.com/Book"
    pattern: "publishers/books/{book}"
  };
  string name = 1;
}

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