Add #with_env_vars

Author: eval

lib/spring/application.rb

@@ -133,12 +133,19 @@ def run
       end
     end
 
-    def set_env_vars(env)
+    def with_env_vars(env)
+      old_env = ENV.to_hash
+
+      # TODO move env-filtering
       # Delete all env vars which are unchanged from before spring started
       original_env.each { |k, v| ENV.delete k if ENV[k] == v }
 
       # Load in the current env vars, except those which *were* changed when spring started
       env.each { |k, v| ENV[k] ||= v }
+
+      yield
+    ensure
+      ENV.replace(old_env.to_hash)
     end
 
     def serve(client)
@@ -150,41 +157,42 @@ def serve(client)
 
       client_args, client_env = JSON.load(client.read(client.gets.to_i)).values_at("args", "env")
 
-      preload unless preloaded?
-      command = Spring.command(client_args.shift)
+      with_env_vars(client_env) do
+        preload unless preloaded?
+        command = Spring.command(client_args.shift)
 
-      connect_database
-      setup command
+        connect_database
+        setup command
 
-      if Rails.application.reloaders.any?(&:updated?)
-        ActionDispatch::Reloader.cleanup!
-        ActionDispatch::Reloader.prepare!
-      end
+        if Rails.application.reloaders.any?(&:updated?)
+          ActionDispatch::Reloader.cleanup!
+          ActionDispatch::Reloader.prepare!
+        end
 
-      pid = fork {
-        IGNORE_SIGNALS.each { |sig| trap(sig, "DEFAULT") }
-        trap("TERM", "DEFAULT")
+        pid = fork {
+          IGNORE_SIGNALS.each { |sig| trap(sig, "DEFAULT") }
+          trap("TERM", "DEFAULT")
 
-        ARGV.replace(client_args)
-        $0 = command.process_title
-        set_env_vars(client_env)
+          ARGV.replace(client_args)
+          $0 = command.process_title
 
-        # requiring is faster, so if config.cache_classes was true in
-        # the environment's config file, then we can respect that from
-        # here on as we no longer need constant reloading.
-        if @original_cache_classes
-          ActiveSupport::Dependencies.mechanism = :require
-          Rails.application.config.cache_classes = true
-        end
+          # requiring is faster, so if config.cache_classes was true in
+          # the environment's config file, then we can respect that from
+          # here on as we no longer need constant reloading.
+          if @original_cache_classes
+            ActiveSupport::Dependencies.mechanism = :require
+            Rails.application.config.cache_classes = true
+          end
 
-        connect_database
-        srand
+          connect_database
+          srand
 
-        invoke_after_fork_callbacks
-        shush_backtraces
+          invoke_after_fork_callbacks
+          shush_backtraces
 
-        command.call
-      }
+          command.call
+        }
+      end
 
       disconnect_database
       reset_streams

test/acceptance/app_test.rb

@@ -292,7 +292,7 @@ def binstub_prelude
   end
 
   test "config via environment variable" do
-    File.write(application.path('config/initializers/set_foo.rb', <<-CONFIG)
+    File.write(application.path('config/initializers/set_foo.rb'), <<-CONFIG)
       Rails.application.config.foo = !!ENV['FOO']
     CONFIG