support AR 4.2 and 5.0 simultaneously

.travis.yml

@@ -7,6 +7,9 @@ sudo: false
 rvm:
 - 2.3.1
 gemfile:
+- gemfiles/activerecord-4.2/Gemfile.mysql2
+- gemfiles/activerecord-4.2/Gemfile.postgresql
+- gemfiles/activerecord-4.2/Gemfile.sqlite3
 - gemfiles/activerecord-5.0/Gemfile.mysql2
 - gemfiles/activerecord-5.0/Gemfile.postgresql
 - gemfiles/activerecord-5.0/Gemfile.sqlite3

README.md

@@ -106,6 +106,7 @@ schema_plus_indexes is tested on
 
 <!-- SCHEMA_DEV: MATRIX - begin -->
 <!-- These lines are auto-generated by schema_dev based on schema_dev.yml -->
+* ruby **2.3.1** with activerecord **4.2**, using **mysql2**, **sqlite3** or **postgresql**
 * ruby **2.3.1** with activerecord **5.0**, using **mysql2**, **sqlite3** or **postgresql**
 
 <!-- SCHEMA_DEV: MATRIX - end -->

gemfiles/activerecord-4.2/Gemfile.base

@@ -0,0 +1,3 @@
+eval File.read File.expand_path('../../Gemfile.base', __FILE__)
+
+gem "activerecord", "~> 4.2.6"

gemfiles/activerecord-4.2/Gemfile.mysql2

@@ -0,0 +1,10 @@
+require "pathname"
+eval(Pathname.new(__FILE__).dirname.join("Gemfile.base").read, binding)
+
+platform :ruby do
+  gem "mysql2", '>= 0.3.18', '< 0.5'
+end
+
+platform :jruby do
+  gem 'activerecord-jdbcmysql-adapter'
+end

gemfiles/activerecord-4.2/Gemfile.postgresql

@@ -0,0 +1,10 @@
+require "pathname"
+eval(Pathname.new(__FILE__).dirname.join("Gemfile.base").read, binding)
+
+platform :ruby do
+  gem "pg"
+end
+
+platform :jruby do
+  gem 'activerecord-jdbcpostgresql-adapter'
+end

gemfiles/activerecord-4.2/Gemfile.sqlite3

@@ -0,0 +1,10 @@
+require "pathname"
+eval(Pathname.new(__FILE__).dirname.join("Gemfile.base").read, binding)
+
+platform :ruby do
+  gem "sqlite3"
+end
+
+platform :jruby do
+  gem 'activerecord-jdbcsqlite3-adapter', '>=1.3.0.beta2'
+end

gemfiles/activerecord-5.0/Gemfile.base

@@ -1,3 +1,3 @@
 eval File.read File.expand_path('../../Gemfile.base', __FILE__)
 
-gem "activerecord", ">= 5.0.0.beta1", "< 5.1"
+gem "activerecord", "~> 5.0.0"

schema_dev.yml

@@ -1,6 +1,7 @@
 ruby:
     - 2.3.1
 activerecord:
+    - 4.2
     - 5.0
 db:
     - mysql2

schema_plus_indexes.gemspec

@@ -17,8 +17,8 @@ Gem::Specification.new do |gem|
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.require_paths = ["lib"]
 
-  gem.add_dependency "activerecord", "~> 5.0"
-  gem.add_dependency "schema_plus_core", "~> 2.0"
+  gem.add_dependency "activerecord", ">= 4.2", "< 5.1"
+  gem.add_dependency "schema_plus_core"
   gem.add_dependency "its-it", "~> 1.2"
 
   gem.add_development_dependency "bundler", "~> 1.7"

spec/command_recorder_spec.rb

@@ -37,7 +37,9 @@ def before(env)
     end
 
     it "does not fail when reverting" do
-      migration = Class.new ::ActiveRecord::Migration[5.0] do
+      migration = ::ActiveRecord::Migration
+      migration = migration[5.0] if migration.respond_to? :[] # without [], will be rails 4.2 migration
+      migration = Class.new migration do
         define_method(:change) {
           change_table("comments") do |t|
             t.integer :column

spec/index_spec.rb

@@ -8,7 +8,7 @@
   describe "add_index" do
 
     before(:each) do
-      connection.tables.each do |table| connection.drop_table table, cascade: true end
+      each_table connection do |table| connection.drop_table table, cascade: true end
 
       define_schema(:auto_create => false) do
         create_table :users, :force => true do |t|
@@ -80,7 +80,7 @@ def index_for(column_names)
   describe "remove_index" do
 
     before(:each) do
-      connection.tables.each do |table| connection.drop_table table, cascade: true end
+      each_table connection do |table| connection.drop_table table, cascade: true end
       define_schema(:auto_create => false) do
         create_table :users, :force => true do |t|
           t.string :login

spec/spec_helper.rb

@@ -24,9 +24,17 @@
   end
 end
 
+# shim to handle connection.tables deprecation in favor of
+# connection.data_sources
+def each_table(connection)
+  (connection.try :data_sources || connection.tables).each do |table|
+    yield table
+  end
+end
+
 def define_schema(config={}, &block)
   ActiveRecord::Schema.define do
-    connection.tables.each do |table|
+    each_table(connection) do |table|
       drop_table table, :force => :cascade
     end
     instance_eval &block