Ensure collisions to work on mongodb 2.6. 3.0 and 4.0

Author: Ricard Forniol

lib/mongoid/token/collisions.rb

@@ -26,7 +26,7 @@ def raise_collision_retries_exceeded_error(field_name, retry_count)
       end
 
       def duplicate_token_error?(err, document, field_name)
-        err.message =~ /(11000|11001)/ &&
+        [11000, 11001].include?(err.code) &&
           err.message =~ /dup key/ &&
           err.message =~ /"#{document.send(field_name)}"/ &&
           true

spec/mongoid/token/collisions_spec.rb

@@ -103,19 +103,36 @@
       document.class.send(:include, Mongoid::Token::Collisions)
     end
     context "when there is a duplicate key error" do
-      it "should return true" do
+      before do
         allow(document).to receive("token").and_return("tokenvalue123")
-        err = double('Mongo::Error::OperationFailure')
-        allow(err).to(receive("message")
-                      .and_return('insertDocument :: caused by :: 11000 E11000'\
-                                  ' duplicate key error index: mongoid_token_'\
-                                  'test.documents.$token_1  dup key: '\
-                                  '{ : "tokenvalue123" } (11000) (on localhost'\
-                                  ':27017, legacy retry, attempt 1) (on localh'\
-                                  'ost:27017, legacy retry, attempt 1)'))
-        expect(document.duplicate_token_error?(err, document, :token)).to(
-          be(true)
-        )
+        allow(err).to(receive("message").and_return(message))
+      end
+      let(:err) { double('Mongo::Error::OperationFailure', code: 11000) }
+      subject { document.duplicate_token_error?(err, document, :token) }
+
+      context "mongodb version 2.6, 3.0" do
+        let(:message) do
+          "insertDocument :: caused by :: 11000 "\
+          "E11000 duplicate key error index: "\
+          "mongoid_token_test.documents.$token_1 "\
+          "dup key: { : \"tokenvalue123\" } (11000) "\
+          "(on localhost:27017, legacy retry, attempt 1) "\
+          "(on localhost:27017, legacy retry, attempt 1)"
+        end
+
+        it { is_expected.to be(true) }
+      end
+
+      context "mongodb version 4" do
+        let(:message) do
+          "E11000 duplicate key error collection: "\
+          "mongoid_token_test.docs index: token_1 "\
+          "dup key: { : \"tokenvalue123\" } (11000) "\
+          "(on localhost:27017, legacy retry, attempt 1) "\
+          "(on localhost:27017, legacy retry, attempt 1)"
+        end
+
+        it { is_expected.to be(true) }
       end
     end
   end

spec/mongoid/token_spec.rb

@@ -182,7 +182,7 @@ class Doc
       let(:doc) { Doc.create(foo: "hello") }
       let(:dup_doc) { Doc.new }
       let(:exception) do
-        /E11000 duplicate key error index: mongoid_token_test.docs\.\$foo_1/
+        /(E11000 duplicate key error index: mongoid_token_test.docs\.\$foo_1|E11000 duplicate key error collection: mongoid_token_test\.docs index: foo_1 dup key)/
       end
 
       it do