Have things working and tests passing on ActiveRecord 5.2

.travis.yml

@@ -1,6 +1,6 @@
 language: ruby
 rvm:
-  - 2.2.1
+  - 2.2.10
   - 2.5.5
   - 2.6.3
 matrix:

Gemfile

@@ -5,15 +5,15 @@ gemspec
 gem 'jruby-openssl', :platform => :jruby
 
 group :test do
-  gem 'activerecord', '~> 4.2.0'
+  gem 'activerecord', '~> 5.2.0'
   gem 'activerecord-jdbcsqlite3-adapter', :platform => [:jruby]
   gem 'libxml-ruby', :platform => [:ruby, :mswin]
   gem 'rake'
   gem 'yard'
   gem 'redcarpet', :platform => :ruby # For fast, Github-like Markdown
   gem 'kramdown', :platform => :jruby # For Markdown without a C compiler
   gem 'test-unit'
-  # This version of sqlite3 required for activerecord 4.2, not more recent.
-  # When bumping AR, may have to/want to adjust this to more recent versions.
-  gem 'sqlite3', "~> 1.3.0", :platform => [:ruby, :mswin]
+
+  # This version of sqlite3 oughta be good for activerecord 5.1+ hopefully
+  gem 'sqlite3', ">= 1.4.0", "< 2.0", :platform => [:ruby, :mswin]
 end

lib/oai/provider/model/activerecord_caching_wrapper.rb

@@ -90,17 +90,16 @@ def next_set(token_string)
     # select a subset of the result set, and return it with a
     # resumption token to get the next subset
     def select_partial(token)
-      if 0 == token.last
-        oaitoken = OaiToken.find_or_create_by(token: token.to_s)
-        if oaitoken.new_record_before_save?
-          OaiToken.connection.execute("insert into " +
-            "#{OaiEntry.table_name} (oai_token_id, record_id) " +
-            "select #{oaitoken.id}, id from #{model.table_name} where " +
-            "#{OaiToken.sanitize_sql(token_conditions(token))}")
-        end
+      oaitoken = OaiToken.find_by(token: token.to_s)
+
+      if 0 == token.last && oaitoken.nil?
+        oaitoken = OaiToken.create!(token: token.to_s)
+        OaiToken.connection.execute("insert into " +
+          "#{OaiEntry.table_name} (oai_token_id, record_id) " +
+          "select #{oaitoken.id}, id from #{model.table_name} where " +
+          "#{OaiToken.sanitize_sql(token_conditions(token))}")
       end
 
-      oaitoken = OaiToken.find_by_token(token.to_s)
       raise ResumptionTokenException.new unless oaitoken
 
       PartialResult.new(
@@ -111,7 +110,7 @@ def select_partial(token)
     end
 
     def sweep_cache
-      OaiToken.destroy_all(["created_at < ?", Time.now - expire])
+      OaiToken.where(["created_at < ?", Time.now - expire]).destroy_all
     end
 
     def hydrate_records(records)

test/activerecord_provider/config/connection.rb

@@ -12,4 +12,7 @@
 ActiveRecord::Migration.verbose = false
 ActiveRecord::Base.establish_connection :adapter => "sqlite3",
                                         :database => ":memory:"
-ActiveRecord::Migrator.up File.join(File.dirname(__FILE__), '..', 'database')
+
+ActiveRecord::MigrationContext.new(File.join(File.dirname(__FILE__), '..', 'database')).migrate
+
+

test/activerecord_provider/database/0001_oaipmh_tables.rb

@@ -1,4 +1,4 @@
-class OaipmhTables < ActiveRecord::Migration
+class OaipmhTables < ActiveRecord::Migration[4.2]
   def self.up
     create_table :oai_tokens do |t|
       t.column :token,      :string,  :null => false

test/activerecord_provider/models/exclusive_set_dc_field.rb

@@ -3,7 +3,7 @@ class ExclusiveSetDCField < ActiveRecord::Base
 
   def self.sets
     klass = Struct.new(:name, :spec)
-    self.uniq.pluck('`set`').compact.map do |spec|
+    self.distinct.pluck(:set).compact.map do |spec|
       klass.new("Set #{spec}", spec)
     end
   end