Move coverage reporting into `brew tests`.

Library/Homebrew/.simplecov

@@ -11,8 +11,6 @@ SimpleCov.start do
   # tests to be dropped. This causes random fluctuations in test coverage.
   merge_timeout 86400
 
-  add_filter "/Homebrew/cask/spec/"
-  add_filter "/Homebrew/cask/test/"
   add_filter "/Homebrew/compat/"
   add_filter "/Homebrew/dev-cmd/tests.rb"
   add_filter "/Homebrew/test/"

Library/Homebrew/cask/.simplecov

-../.simplecov
\ No newline at end of file

Library/Homebrew/cask/cmd/brew-cask-tests.rb

-require "English"
-
-ENV["BUNDLE_GEMFILE"] = "#{HOMEBREW_LIBRARY_PATH}/cask/Gemfile"
-ENV["BUNDLE_PATH"] = "#{HOMEBREW_LIBRARY_PATH}/vendor/bundle"
-
-def run_tests(executable, files, args = [])
-  opts = []
-  opts << "--serialize-stdout" if ENV["CI"]
-
-  system "bundle", "exec", executable, *opts, "--", *args, "--", *files
-end
-
-cask_root = Pathname.new(__FILE__).realpath.parent.parent
-cask_root.cd do
-  ENV["HOMEBREW_NO_ANALYTICS_THIS_RUN"] = "1"
-  ENV["HOMEBREW_NO_EMOJI"] = "1"
-  ENV.delete("HOMEBREW_CASK_OPTS")
-
-  Homebrew.install_gem_setup_path! "bundler"
-  unless quiet_system("bundle", "check")
-    system "bundle", "install"
-  end
-
-  if ARGV.flag?("--coverage")
-    ENV["HOMEBREW_TESTS_COVERAGE"] = "1"
-    upload_coverage = ENV["CODECOV_TOKEN"] || ENV["TRAVIS"]
-  end
-
-  if upload_coverage
-    puts "Submitting Codecov coverage..."
-    system "bundle", "exec", "spec/upload_coverage.rb"
-  end
-end

Library/Homebrew/cask/spec/upload_coverage.rb

-#!/usr/bin/env ruby
-require "simplecov"
-require "codecov"
-
-formatter = SimpleCov::Formatter::Codecov.new
-formatter.format SimpleCov::ResultMerger.merged_result

Library/Homebrew/test/spec_helper.rb

 require "find"
+require "parallel_tests"
 require "pathname"
 require "rspec/its"
 require "rspec/wait"
@@ -6,6 +7,20 @@ require "set"
 
 if ENV["HOMEBREW_TESTS_COVERAGE"]
   require "simplecov"
+
+  if ENV["CODECOV_TOKEN"] || ENV["TRAVIS"]
+    require "codecov"
+
+    if ParallelTests.last_process?
+      at_exit do
+        ParallelTests.wait_for_other_processes_to_finish
+
+        puts "Sending coverage report to CodeCov …"
+        formatter = SimpleCov::Formatter::Codecov.new
+        formatter.format SimpleCov::ResultMerger.merged_result
+      end
+    end
+  end
 end
 
 $LOAD_PATH.unshift(File.expand_path("#{ENV["HOMEBREW_LIBRARY"]}/Homebrew"))