[Update] Warn when an explicitly updated spec does not get a newer ve…

…rsion

lib/bundler/cli/update.rb

@@ -67,6 +67,21 @@ def run
         Bundler::CLI::Clean.new(options).run
       end
 
+      if locked_gems = Bundler.definition.locked_gems
+        gems.each do |name|
+          locked_version = locked_gems.specs.find {|s| s.name == name }.version
+          new_version = Bundler.definition.specs[name].first
+          new_version &&= new_version.version
+          if !new_version
+            Bundler.ui.warn "Bundler attempted to update #{name} but it was removed from the bundle"
+          elsif new_version < locked_version
+            Bundler.ui.warn "Bundler attempted to update #{name} but its version regressed from #{locked_version} to #{new_version}"
+          elsif new_version == locked_version
+            Bundler.ui.warn "Bundler attempted to update #{name} but its version stayed the same"
+          end
+        end
+      end
+
       Bundler.ui.confirm "Bundle updated!"
       Bundler::CLI::Common.output_without_groups_message
       Bundler::CLI::Common.output_post_install_messages installer.post_install_messages

spec/commands/update_spec.rb

@@ -373,6 +373,24 @@
     expect(the_bundle).to include_gems "thin 2.0", "rack 1.2", "rack-obama 1.0"
   end
 
+  it "will warn when some explicitly updated gems are not updated" do
+    install_gemfile! <<-G
+      source "file:#{gem_repo2}"
+
+      gem "thin"
+      gem "rack-obama"
+    G
+
+    update_repo2 do
+      build_gem("thin", "2.0") {|s| s.add_dependency "rack" }
+      build_gem "rack", "10.0"
+    end
+
+    bundle! "update thin rack-obama"
+    expect(last_command.stdboth).to include "Bundler attempted to update rack-obama but its version stayed the same"
+    expect(the_bundle).to include_gems "thin 2.0", "rack 10.0", "rack-obama 1.0"
+  end
+
   it "will update only from pinned source" do
     install_gemfile <<-G
       source "file://#{gem_repo2}"