Extract PL/SQL boolean conversion helpers in ProcedureCall

[yahonda]

Summary

ProcedureCall had the same two-and-a-half boolean conversion patterns scattered across four call sites:

• value.nil? ? nil : (value ? 1 : 0) (Ruby → NUMBER(1) for bind values) — 2 sites
• numeric_value.nil? ? nil : numeric_value == 1 (NUMBER(1) → Ruby on the way back) — 2 sites
• metadata.merge(data_type: "NUMBER", data_precision: 1) (override the bind metadata so the BOOLEAN parameter rides on a NUMBER bind) — 4 sites

PL/SQL BOOLEAN cannot be bound through the SQL layer, so the library swaps in a NUMBER(1) bind and re-assigns on the server side. That trick currently has its conversion code copy-pasted across add_argument, record_assignment_sql_values_metadata, add_return_variable, and return_variable_value, which makes any future change to how booleans are marshalled (e.g. accepting 'Y'/'N', aligning JDBC) a multi-site edit.

This PR introduces three small private helpers and one frozen constant on ProcedureCall, and replaces the eight call sites. Behavior is unchanged.

PLSQL_BOOLEAN_METADATA = { data_type: "NUMBER", data_precision: 1 }.freeze

def ruby_value_to_plsql_boolean(value)
  value.nil? ? nil : (value ? 1 : 0)
end

def plsql_boolean_to_ruby_value(numeric_value)
  numeric_value.nil? ? nil : numeric_value == 1
end

def plsql_boolean_metadata(base_metadata)
  base_metadata.merge(PLSQL_BOOLEAN_METADATA)
end

Out of scope on purpose:

• The PL/SQL string literals (CASE WHEN ... THEN 1 ..., IF ... THEN o_x := 1 ...) that build the server-side conversion remain unchanged — those are SQL generation, not Ruby-side value conversion.
• jdbc_connection.rb, oci_connection.rb, and procedure.rb boolean handling are not touched in this PR.

Diff stat: lib/plsql/procedure_call.rb | 30 ++++++++++++++++++++++-------- (+22 / -8), no other files modified.

Test plan

• bundle exec rspec spec/plsql/procedure_spec.rb -e "boolean" — 15 examples, 0 failures
• bundle exec rspec spec/plsql/procedure_spec.rb — 195 examples, 0 failures, 1 pre-existing pending (the Oracle 9.2 indexed-by-binary-integer skip at procedure_spec.rb:1525)
• ruby -c lib/plsql/procedure_call.rb passes
• No remaining occurrences of value.nil? ? nil : (value ? 1 : 0), nil? ? nil : * == 1, or the literal data_type: "NUMBER", data_precision: 1 outside the new helpers/constant

Tested locally against Oracle AI Database 23ai Free (FREEPDB1) on macOS with MRI Ruby 4.0.4 + ruby-oci8 2.2.14. CI will exercise the JDBC path as well.

🤖 Generated with Claude Code