Arvados

The operand of a @@ filter should be checked against a well-defined format.

• If the operand does not follow this format, the request should be rejected 4xx.
• If the operand does follow this format, the request should behave predictably.

Specifically:

• API should support queries like "foo bar", "foo & bar", "foo*&bar*", "foo* bar", "foo|bar" where "*" enables prefix matching, & means and, and | means or.
• At least for now, queries with non-alphanumeric characters other than |&* and space should return 422 errors; likewise malformed queries like "&foo", "bar&", "foo&&bar", "foo& |bar".
• Except: for compatibility, start by silently replacing :* with *.

Also:

• A query like "a" ("a" being a "stop word") should match everything. This is consistent with the behavior of "foobar a", which matches everything containing "foobar". (Currently, "a" matches nothing.)
  • This can be implemented by passing the supplied search string through select to_tsquery(x) and skipping the filter entirely if the result is empty.

When implementing, please review the Workbench portion of this story done in #12194 to ensure expectations match.