Failure

spec/bson/byte_buffer_write_spec.rb:508 ("BSON::ByteBuffer#put_double when argument is a string raises TypeError") fails on Ruby head:

expected TypeError with message matching /no implicit conversion to float from string|ClassCastException:.*RubyString cannot be cast to.*RubyFloat/, got #<TypeError: no implicit conversion of String into Float>

Cause

Ruby head changed the wording of the standard TypeError message produced when coercing a String to a Float:

• Ruby ≤ 3.4: no implicit conversion to float from string
• Ruby head: no implicit conversion of String into Float

The current regex on line 511 only matches the old MRI wording (or the JRuby ClassCastException form). The C extension's put_double propagates the standard Ruby TypeError verbatim, so when Ruby's wording changes the spec breaks.

Fix

Extend the regex on spec/bson/byte_buffer_write_spec.rb:511 to accept both wordings, e.g.:

/no implicit conversion to float from string|no implicit conversion of String into Float|ClassCastException:.*RubyString cannot be cast to.*RubyFloat/i

No production code changes; this is purely a test-message-tolerance fix.

Notes

Surfaced while running CI on the RUBY-3860 branch; not related to that ticket. Filed separately to keep the security PR focused.