Field names: Lower Snake Case

This rule enforces that field names use snake_case, as mandated in AIP-140.

Details

This rule checks every field in the proto and complains if the field name contains a capital letter.

Examples

Single word method

Incorrect code for this rule:

// Incorrect.
message Book {
  string name = 1;
  int32 pageCount = 2;  // Should be `page_count`.
}

Correct code for this rule:

// Correct.
message Book {
  string name = 1;
  int32 page_count = 2;
}

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::0140::lower-snake=disabled
//     aip.dev/not-precedent: We need to do this because reasons. --)
message Book {
  string name = 1;
  string pageCount = 2;
}

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