From 5546343bff249e04eca6d4334cc9c93a59c62875 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Mon, 7 Sep 2026 11:54:10 +0000
Subject: [PATCH] Stop injecting rails_12factor from the Heroku generator
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`rails generate ember:heroku` added `rails_12factor` to the `Gemfile`
for the `staging` and `production` groups.
The gem exists to backport twelve-factor behaviour — logging to stdout and
serving static assets in production — onto Rails 4,
which Rails has done natively since `5.0`.
Its own README says a new Rails 5 application does not need it,
and its repository was archived in February 2022.

Every Rails version this gem supports is `>= 5.2`,
so the injection could only ever add an unmaintained dependency
to a project that has no use for it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014rAfkAVGVifbaEoTVeT66u
---
 CHANGELOG.md                                  |  8 ++++++++
 lib/generators/ember/heroku/USAGE             |  3 ---
 .../ember/heroku/heroku_generator.rb          |  4 ----
 .../ember/heroku/heroku_generator_spec.rb     | 19 +++++++++++++++++--
 4 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e96a71b8..7a3a8d31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,11 @@
+main
+------
+
+* Stop adding `rails_12factor` to the `Gemfile` from `rails generate
+  ember:heroku`. Rails serves the twelve-factor behaviour the gem backported
+  natively since `5.0`, and every Rails version this gem supports is `>= 5.2`.
+  To upgrade, remove `rails_12factor` from your project's `Gemfile`
+
 0.13.2
 ------
 
diff --git a/lib/generators/ember/heroku/USAGE b/lib/generators/ember/heroku/USAGE
index 2c309fd8..dccfe909 100644
--- a/lib/generators/ember/heroku/USAGE
+++ b/lib/generators/ember/heroku/USAGE
@@ -11,8 +11,5 @@ Description:
 Example:
     rails generate ember:heroku
 
-    This will install the following gems:
-        rails_12factor
-
     This will create:
         package.json
diff --git a/lib/generators/ember/heroku/heroku_generator.rb b/lib/generators/ember/heroku/heroku_generator.rb
index 522c3232..37cddfb7 100644
--- a/lib/generators/ember/heroku/heroku_generator.rb
+++ b/lib/generators/ember/heroku/heroku_generator.rb
@@ -14,10 +14,6 @@ def identify_as_yarn_project
       end
     end
 
-    def inject_12factor_gem
-      gem "rails_12factor", group: [:staging, :production]
-    end
-
     private
 
     def cache_directories
diff --git a/spec/generators/ember/heroku/heroku_generator_spec.rb b/spec/generators/ember/heroku/heroku_generator_spec.rb
index 77529478..51d86442 100644
--- a/spec/generators/ember/heroku/heroku_generator_spec.rb
+++ b/spec/generators/ember/heroku/heroku_generator_spec.rb
@@ -31,6 +31,21 @@
     end
   end
 
+  describe "Gemfile" do
+    it "leaves the Gemfile untouched" do
+      setup_destination
+      configure_application
+
+      run_generator
+
+      expect(gemfile_contents).to eq("")
+    end
+
+    def gemfile_contents
+      destination_root.join("Gemfile").read
+    end
+  end
+
   describe "package.json" do
     it "includes the root directory node_modules" do
       setup_destination
@@ -113,10 +128,10 @@ def configure_application(**options)
   def setup_destination
     prepare_destination
 
-    create_empty_gemfile_for_bundler
+    create_empty_gemfile
   end
 
-  def create_empty_gemfile_for_bundler
+  def create_empty_gemfile
     FileUtils.touch(destination_root.join("Gemfile"))
   end
 end