From 34ab41d39b49025e080515093611bb8cc00e4175 Mon Sep 17 00:00:00 2001
From: Jared Beck <jared@jaredbeck.com>
Date: Sat, 10 Dec 2016 13:49:41 -0500
Subject: [PATCH] Test AR 4.2 locally, without dropping support for 4.0

See notes in boot.rb about `enum`
---
 .github/CONTRIBUTING.md   | 50 ++++++++++++++++++++++++++++++++-------
 test/dummy/config/boot.rb | 25 +++++++++++++++-----
 2 files changed, 61 insertions(+), 14 deletions(-)

diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index aecfe29e..c5c33c54 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -28,43 +28,73 @@ Testing is a little awkward because the test suite:
 1. Contains a "dummy" rails app with three databases (test, foo, and bar)
 1. Supports three different RDBMS': sqlite, mysql, and postgres
 
-### Run tests with sqlite
+### Test sqlite, AR 4.2
 
 ```
 # Create the appropriate database config. file
 rm test/dummy/config/database.yml
 DB=sqlite bundle exec rake prepare
 
-# If this is the first test run ever, create databases
+# If this is the first test run ever, create databases.
+# We can't use `appraisal` inside the test dummy, so we must set `BUNDLE_GEMFILE`.
+# See test/dummy/config/boot.rb for a complete explanation.
 cd test/dummy
+export BUNDLE_GEMFILE=../../gemfiles/ar_4.2.gemfile
 RAILS_ENV=test bundle exec rake db:setup
 RAILS_ENV=foo bundle exec rake db:setup
 RAILS_ENV=bar bundle exec rake db:setup
+unset BUNDLE_GEMFILE
+cd ../..
+
+# Run tests
+DB=sqlite bundle exec appraisal ar-4.2 rake
+```
+
+### Test sqlite, AR 5
+
+```
+# Create the appropriate database config. file
+rm test/dummy/config/database.yml
+DB=sqlite bundle exec rake prepare
+
+# If this is the first test run ever, create databases.
+# We can't use `appraisal` inside the test dummy, so we must set `BUNDLE_GEMFILE`.
+# See test/dummy/config/boot.rb for a complete explanation.
+cd test/dummy
+export BUNDLE_GEMFILE=../../gemfiles/ar_5.0.gemfile
+RAILS_ENV=test bundle exec rake db:environment:set db:setup
+RAILS_ENV=foo bundle exec rake db:environment:set db:setup
+RAILS_ENV=bar bundle exec rake db:environment:set db:setup
+unset BUNDLE_GEMFILE
 cd ../..
 
 # Run tests
 DB=sqlite bundle exec appraisal ar-5.0 rake
 ```
 
-### Run tests with mysql
+### Test mysql, AR 5
 
 ```
 # Create the appropriate database config. file
 rm test/dummy/config/database.yml
 DB=mysql bundle exec rake prepare
 
-# If this is the first test run ever, create databases
+# If this is the first test run ever, create databases.
+# We can't use `appraisal` inside the test dummy, so we must set `BUNDLE_GEMFILE`.
+# See test/dummy/config/boot.rb for a complete explanation.
 cd test/dummy
-RAILS_ENV=test bundle exec rake db:setup
-RAILS_ENV=foo bundle exec rake db:setup
-RAILS_ENV=bar bundle exec rake db:setup
+export BUNDLE_GEMFILE=../../gemfiles/ar_5.0.gemfile
+RAILS_ENV=test bundle exec rake db:environment:set db:setup
+RAILS_ENV=foo bundle exec rake db:environment:set db:setup
+RAILS_ENV=bar bundle exec rake db:environment:set db:setup
+unset BUNDLE_GEMFILE
 cd ../..
 
 # Run tests
 DB=mysql bundle exec appraisal ar-5.0 rake
 ```
 
-### Run tests with postgres
+### Test postgres, AR 5
 
 ```
 # Create the appropriate database config. file
@@ -73,10 +103,14 @@ DB=postgres bundle exec rake prepare
 
 # If this is the first test run ever, create databases.
 # Unlike mysql, use create/migrate instead of setup.
+# We can't use `appraisal` inside the test dummy, so we must set `BUNDLE_GEMFILE`.
+# See test/dummy/config/boot.rb for a complete explanation.
 cd test/dummy
+export BUNDLE_GEMFILE=../../gemfiles/ar_5.0.gemfile
 DB=postgres RAILS_ENV=test bundle exec rake db:drop db:create db:migrate
 DB=postgres RAILS_ENV=foo bundle exec rake db:drop db:create db:migrate
 DB=postgres RAILS_ENV=bar bundle exec rake db:drop db:create db:migrate
+unset BUNDLE_GEMFILE
 cd ../..
 
 # Run tests
diff --git a/test/dummy/config/boot.rb b/test/dummy/config/boot.rb
index 7a2e617e..bdf2c11a 100644
--- a/test/dummy/config/boot.rb
+++ b/test/dummy/config/boot.rb
@@ -1,10 +1,23 @@
 require "rubygems"
-gemfile = File.expand_path("../../../../Gemfile", __FILE__)
 
-if File.exist?(gemfile)
-  ENV["BUNDLE_GEMFILE"] = gemfile
-  require "bundler"
-  Bundler.setup
+# Set ENV['BUNDLE_GEMFILE'] as follows:
+#
+# Our test dummy app uses `enum`, so it must use AR >= 4.1. However, we want our
+# gemspec to support AR >= 4.0. For local test runs, using our root Gemfile
+# would be problematic here. For TravisCI it seems to be fine. Maybe Travis
+# overwrites the root Gemfile?
+if ENV.key?("BUNDLE_GEMFILE")
+  # This is a local test run, and we are running rake tasks in this dummy app,
+  # and we can't use the project's root Gemfile for the reasons given above.
+  puts "Booting PT test dummy app: Using BUNDLE_GEMFILE: #{ENV.fetch('BUNDLE_GEMFILE')}"
+else
+  gemfile = File.expand_path("../../../../Gemfile", __FILE__)
+  if File.exist?(gemfile)
+    puts "Booting PT test dummy app: Using gemfile: #{gemfile}"
+    ENV["BUNDLE_GEMFILE"] = gemfile
+  end
 end
+require "bundler"
+Bundler.setup
 
-$LOAD_PATH.unshift File.expand_path("../../../../lib", __FILE__)
+$LOAD_PATH.unshift(File.expand_path("../../../../lib", __FILE__))