Add optional SQL logging spec helper

Set PLSQL_DEBUG_LOG=debug.log when running rspec to capture every SQL
statement issued by PLSQL::OCIConnection / PLSQL::JDBCConnection (exec,
cursor_from_query, parse) plus any SQL emitted via ActiveRecord::Base
when specs use plsql.activerecord_class. Logger arguments mirror those
used in the activerecord-oracle_enhanced-adapter spec helper.

logger is added to the Gemfile because it is a bundled gem on Ruby 3.5+
and would otherwise be unavailable when NO_ACTIVERECORD=1 (which skips
activerecord, the gem that pulls logger in transitively).

Author: yahonda

Gemfile

@@ -14,6 +14,7 @@ end
 group :test, :development do
   gem "rake", ">= 10.0"
   gem "rspec", "~> 3.1"
+  gem "logger"
 
   unless ENV["NO_ACTIVERECORD"]
     gem "activerecord", github: "rails/rails", branch: "main"

spec/support/sql_logger.rb

@@ -0,0 +1,35 @@
+# Enable with: PLSQL_DEBUG_LOG=debug.log bundle exec rspec
+# Logger args mirror activerecord-oracle_enhanced-adapter's spec logger
+# (shift_age, shift_size) so debug.log behaves the same way.
+if (log_path = ENV["PLSQL_DEBUG_LOG"]) && !log_path.empty?
+  require "logger"
+
+  PLSQL_DEBUG_LOGGER = Logger.new(log_path, 0, 100 * 1024 * 1024)
+  PLSQL_DEBUG_LOGGER.formatter = ->(_sev, time, _prog, msg) {
+    "#{time.iso8601(6)}  #{msg}\n"
+  }
+
+  module PLSQLSQLLogger
+    def exec(sql, *bindvars)
+      PLSQL_DEBUG_LOGGER.info("EXEC   #{sql.strip}#{bindvars.empty? ? '' : "  BINDS=#{bindvars.inspect}"}")
+      super
+    end
+
+    def cursor_from_query(sql, bindvars = [], options = {})
+      PLSQL_DEBUG_LOGGER.info("QUERY  #{sql.strip}#{bindvars.empty? ? '' : "  BINDS=#{bindvars.inspect}"}")
+      super
+    end
+
+    def parse(sql)
+      PLSQL_DEBUG_LOGGER.info("PARSE  #{sql.strip}")
+      super
+    end
+  end
+
+  PLSQL::OCIConnection.prepend(PLSQLSQLLogger)  if defined?(PLSQL::OCIConnection)
+  PLSQL::JDBCConnection.prepend(PLSQLSQLLogger) if defined?(PLSQL::JDBCConnection)
+
+  if defined?(ActiveRecord::Base)
+    ActiveRecord::Base.logger = PLSQL_DEBUG_LOGGER
+  end
+end