Fix error with annonymous ActiveRecord classes

Marcel M. Cary · Marcel M. Cary · commit fa27fa2cc485 · 2017-03-21T16:32:26.000-07:00
I'm seeing this error while running any spec for ActiveRecord Source or Sink classes: Anonymous class is not allowed The problem is that support for "Class.new(ActiveRecord::Base)" (aka anonymous subclasses) was dropped in recent versions of Rails. (rails/rails#8934) Find another way to generate AR classes.
diff --git a/lib/wolverine/active_record_class_generator.rb b/lib/wolverine/active_record_class_generator.rb
@@ -0,0 +1,23 @@
+module Wolverine
+  class ActiveRecordClassGenerator
+    def initialize(mod, table_name)
+      @mod = mod
+      @table_name = table_name
+    end
+    def generate
+      # This is no longer permitted by AR: Class.new(ActiveRecord::Base)
+      klass_name = [
+        "Record",
+        table_name.gsub(/[^a-z0-9]+/i, '_'),
+        Time.now.to_i,
+        rand(100_000_000..1_000_000_000),
+      ].join("_")
+      eval "class #{mod.name}::#{klass_name} < ActiveRecord::Base; end"
+      klass = mod.const_get(klass_name, inherit=false)
+      klass.table_name = table_name
+      klass
+    end
+    private
+    attr_reader :mod, :table_name
+  end
+end
diff --git a/lib/wolverine/active_record_sink.rb b/lib/wolverine/active_record_sink.rb
@@ -1,3 +1,5 @@
+require 'wolverine/active_record_class_generator'
+
 module Wolverine
   class ActiveRecordSink < Sink
     attr_reader :columns, :klass
@@ -8,8 +10,8 @@ def initialize(source, klass)
     end
     def self.create(source, table_name, columns, connection_params)
       require 'active_record'
-      klass = Class.new(ActiveRecord::Base)
-      klass.class_eval { self.table_name = table_name }
+      gen = ActiveRecordClassGenerator.new(self, table_name)
+      klass = gen.generate
       klass.establish_connection(connection_params)
       klass.connection.create_table table_name do |t|
         t.column :text, :text
diff --git a/lib/wolverine/active_record_source.rb b/lib/wolverine/active_record_source.rb
@@ -1,3 +1,5 @@
+require 'wolverine/active_record_class_generator'
+
 module Wolverine
   class ActiveRecordSource < Source
     attr_reader :klass
@@ -10,9 +12,9 @@ def initialize(active_record_klass, conditions={}, search=nil)
     end
     def self.open(table_name, connection_params)
       require 'active_record'
-      klass = Class.new(ActiveRecord::Base)
+      gen = ActiveRecordClassGenerator.new(self, table_name)
+      klass = gen.generate
       klass.class_eval do
-        self.table_name = table_name
         def to_s
           text
         end
diff --git a/spec/wolverine/active_record_sink_spec.rb b/spec/wolverine/active_record_sink_spec.rb
@@ -5,14 +5,16 @@
     Tempfile.open("wol-spec") do |file|
       source = Wolverine::ArraySource.new(["x y"])
       filt = Wolverine::FieldFilter.new(source, /(x)/, :x)
+      config = { :adapter => "sqlite3", :database => file.path }
       sink = Wolverine::ActiveRecordSink.create(filt, "events", [:x],
-                                                :adapter => "sqlite3",
-                                                :database => file.path)
+                                                config)
 
       sink.run
 
-      klass = Class.new(ActiveRecord::Base)
-      klass.class_eval { self.table_name = "events" }
+      gen = Wolverine::ActiveRecordClassGenerator.
+        new(self.class, "events")
+      klass = gen.generate
+      klass.establish_connection(config)
       events = klass.all
       events.length.should == 1
       events.first.x.should == "x"
