[rubygems/rubygems] Implement Bundler::Source::Rubygems#no_remotes?

This method is created to tell whether any remote exist in the object or not and it will be used by `Bundler:SourceList` to tell if a global source has been defined implicitly or not.

https://github.com/rubygems/rubygems/commit/47e3ff0e47

lib/bundler/source/rubygems.rb

@@ -71,6 +71,10 @@ module Bundler
         @remotes.size > 1
       end
 
+      def no_remotes?
+        @remotes.size == 0
+      end
+
       def can_lock?(spec)
         return super unless multiple_remotes?
         include?(spec.source)

spec/bundler/bundler/source/rubygems_spec.rb

@@ -30,4 +30,18 @@ RSpec.describe Bundler::Source::Rubygems do
       end
     end
   end
+
+  describe "#no_remotes?" do
+    context "when no remote provided" do
+      it "returns a truthy value" do
+        expect(described_class.new("remotes" => []).no_remotes?).to be_truthy
+      end
+    end
+
+    context "when a remote provided" do
+      it "returns a falsey value" do
+        expect(described_class.new("remotes" => ["https://rubygems.org"]).no_remotes?).to be_falsey
+      end
+    end
+  end
 end