cleanup mysql implementation

Author: seuros

Makefile

@@ -1,14 +1,17 @@
-.PHONY: test-pg test-mysql
+.PHONY: test-sqlite test-pg test-mysql
+
+test-sqlite:
+	appraisal rake test
 
 test-pg:
 	docker compose up -d pg
 	sleep 10 # give some time for the service to start
-	DATABASE_URL=postgres://with_advisory:with_advisory_pass@localhost/with_advisory_lock_test appraisal activerecord-7.1 rake test
+	DATABASE_URL=postgres://with_advisory:with_advisory_pass@localhost/with_advisory_lock_test appraisal rake test
 
 test-mysql:
 	docker compose up -d mysql
 	sleep 10 # give some time for the service to start
-	DATABASE_URL=mysql2://with_advisory:[email protected]:3306/with_advisory_lock_test appraisal activerecord-7.1 rake test
+	DATABASE_URL=mysql2://with_advisory:[email protected]:3306/with_advisory_lock_test appraisal rake test
 
 
-test: test-pg test-mysql
+test: test-sqlite test-pg test-mysql

lib/with_advisory_lock/database_adapter_support.rb

@@ -1,11 +1,12 @@
-# frozen_string_literal: true
+c# frozen_string_literal: true
 
 module WithAdvisoryLock
   class DatabaseAdapterSupport
     attr_reader :adapter_name
+
     def initialize(connection)
       @connection = connection
-      @adapter_name   = connection.adapter_name.downcase.to_sym
+      @adapter_name = connection.adapter_name.downcase.to_sym
     end
 
     def mysql?
@@ -17,7 +18,7 @@ def postgresql?
     end
 
     def sqlite?
-      [:sqlite3, :sqlite].include? adapter_name
+      %i[sqlite3 sqlite].include? adapter_name
     end
   end
 end

lib/with_advisory_lock/mysql.rb

@@ -5,7 +5,8 @@ class MySQL < Base
     # Caches nested lock support by MySQL reported version
     @@mysql_nl_cache       = {}
     @@mysql_nl_cache_mutex = Mutex.new
-    # See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
+    # See https://dev.mysql.com/doc/refman/5.7/en/locking-functions.html
+    # See https://dev.mysql.com/doc/refman/8.0/en/locking-functions.html
     def try_lock
       raise ArgumentError, 'shared locks are not supported on MySQL' if shared
       raise ArgumentError, 'transaction level locks are not supported on MySQL' if transaction
@@ -18,8 +19,8 @@ def release_lock
     end
 
     def execute_successful?(mysql_function)
-      sql = "SELECT #{mysql_function} AS #{unique_column_name}"
-      connection.select_value(sql).to_i.positive?
+      sql = "SELECT #{mysql_function}"
+      connection.query_value(sql) == 1
     end
 
     # MySQL wants a string as the lock key.