[devin-ai-integration]

Summary

Fixes the three bugs found in the pre-release sweep, and checks the two suspicions. Each fix comes with a test that fails on main.

Bugs

1. Enum values that are Ruby keywords or invalid constant names (pg, mysql2). Before, 'begin' / 'end' generated BEGIN = 'begin', which is a SyntaxError, so the whole package failed to load. 'all' collided with the module's ALL list.
   • Fix: Code.constant_name adds _ to BEGIN / END / ALL (END_, ALL_). unique_constants adds _2, _3, ... until the name is free, including names it produced itself.
   • Test: test_enum_values_named_like_ruby_keywords_get_valid_constants (E2E pg + mysql2). New step enums round-trip every value: begin, end, all, BEGIN, nil, self, __FILE__, do.
2. Interrupt window at BEGIN / COMMIT (pg, mysql2, sqlite3). Before, a Timeout / Thread#raise that arrived right after BEGIN returned skipped the rollback, so the connection went back to the pool inside an open transaction. The same happened when COMMIT itself raised before it ran.

   • Fix: transaction runs inside Thread.handle_interrupt(Object => :never), and only the block runs with :immediate. BEGIN runs inside the protected begin, and the rescue rolls back when BEGIN ran. If COMMIT raises, the transaction is rolled back. legacy_transaction_template (Ruby < 3.3) is adapted to the new layout.

   • Test: test_interrupts_around_begin_and_commit_never_leave_the_{connection,database}_in_a_transaction (E2E, all three engines). A client or database lands one of these deterministically:

     • a Thread#raise right after BEGIN,
     • an exception raised by BEGIN,
     • an exception raised by COMMIT.

     The test then checks that nothing is left open and that later calls commit.

3. RuboCop Naming/VariableNumber on Ruby < 3.2 (all engines). Before, Struct rows of unnamed columns were built with GetUnnamedColumnsRow.new(column_1: ...).
   • Fix: MethodGen disables Naming/VariableNumber around a method whose keyword row/model constructor names end in _<digits>.
   • Test: test_ruby31_struct_rows_of_unnamed_columns_are_rubocop_clean (unit, because RuboCop on generated code is not reachable from E2E). It generates every fixture with rubyVersion: 3.1 and runs the Naming cops.

Suspicions

• pg after DEALLOCATE ALL / DISCARD ALL: this is a real bug. Every later call on that pooled connection raised PG::InvalidSqlStatementName. Prepared execution now goes through a run_prepared helper, which prepares a dropped statement again when the connection is outside a transaction. Inside a transaction the error has already aborted it, so the error is raised and the transaction rolls back. Test: test_statements_are_prepared_again_after_deallocate_all (E2E pg).
• README "json is parsed" vs MySQL: this is a docs mismatch. The README now says MySQL JSON columns and parameters are JSON text Strings, which is what mysql2 returns and what the RBS already declares.

Other changes

• examples/ regenerated, golden files rewritten, test/fixtures/{pg,mysql2}.bin re-captured with sqlc 1.27.0, and steep_expectations.yml refreshed.
• New Steep warnings: RBS 4.2 declares Thread.handle_interrupt without a block (fixed in RBS master), so Steep reports UnexpectedBlockGiven.
• README and docs/Coverage.md are updated.

Checklist

• examples/ is regenerated (rake sqlc_generate_process) and committed
• Tests added or updated (rake test, and rake end2end_* when the generated code changes)
• The generated code stays RuboCop-clean (rake rubocop) and Steep-clean (rake steep)
• Labelled (bug, enhancement, documentation, or breaking) so the release notes are grouped correctly

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring