Fix asset_pipeline_spec

Looks like rake or rspec will clean the previous BUNDLE_GEMFILE env. Workaround is to store the original one and set directly while shelling out.

Author: zetachang

Rakefile

@@ -2,6 +2,9 @@ require 'bundler'
 Bundler.require
 Bundler::GemHelper.install_tasks
 
+# Store the BUNDLE_GEMFILE env, since rake or rspec seems to clean it
+# while invoking task.
+ENV['REAL_BUNDLE_GEMFILE'] = ENV['BUNDLE_GEMFILE']
 
 require 'rspec/core/rake_task'
 require 'opal/rspec/rake_task'

spec/reactive-ruby/rails/asset_pipeline_spec.rb

@@ -3,8 +3,8 @@
 if ruby?
 RSpec.describe 'test_app generator' do
   it "does not interfer with asset precompilation" do
-    env = { "BUNDLE_GEMFILE" => ENV['BUNDLE_GEMFILE'] }
-    expect(system(env, "cd spec/test_app; bundle exec rake assets:precompile")).to be_truthy
+    cmd = "cd spec/test_app; BUNDLE_GEMFILE=#{ENV['REAL_BUNDLE_GEMFILE']} bundle exec rake assets:precompile"
+    expect(system(cmd)).to be_truthy
   end
 end
 end