Merge pull request #11847 from mkllnk/spec-opt

Avoid precompiling assets unnecessarily

spec/spec_helper.rb

@@ -4,12 +4,6 @@ require 'base_spec_helper'
 require 'database_cleaner'
 
 RSpec.configure do |config|
-  # Precompile Webpacker assets (once) when starting the suite. The default setup can result
-  # in the assets getting compiled many times throughout the build, slowing it down.
-  config.before :suite do
-    Webpacker.compile
-  end
-
   # Fix encoding issue in Rails 5.0; allows passing empty arrays or hashes as params.
   config.before(:each, type: :controller) { @request.env["CONTENT_TYPE"] = 'application/json' }
 end

spec/support/precompile_assets.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+RSpec.configure do |config|
+  config.before(:suite) do
+    # We can use webpack-dev-server for tests, too!
+    # Useful if you working on a frontend code fixes and want to verify them via system tests.
+    next if Webpacker.dev_server.running?
+
+    specs_needing_assets = %i[controller feature mailer request system view]
+    examples = RSpec.world.filtered_examples.values.flatten
+    types = examples.map(&:metadata).pluck(:type).uniq
+
+    if types.intersect?(specs_needing_assets)
+      $stdout.puts "\n Precompiling assets.\n"
+      Webpacker.compile
+    end
+  end
+end

spec/system/support/precompile_assets.rb

@@ -1,23 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.configure do |config|
-  # Skip assets precompilcation if we exclude system specs.
-  # For example, you can run all non-system tests via the following command:
-  #
-  #    rspec --tag ~type:system
-  #
-  # In this case, we don't need to precompile assets.
-  next if
-    config.filter.opposite.rules[:type] == "system" ||
-    config.exclude_pattern.match?(%r{spec/system})
-
-  config.before(:suite) do
-    # We can use webpack-dev-server for tests, too!
-    # Useful if you working on a frontend code fixes and want to verify them via system tests.
-    next if Webpacker.dev_server.running?
-
-    $stdout.puts "\n Precompiling assets.\n"
-
-    Webpacker.compile
-  end
-end