Merge pull request #4648 from gmcgibbon/cache

Set GraphQL cache regardless of bootsnap

guides/parser_cache.md

@@ -0,0 +1,12 @@
+---
+layout: guide
+doc_stub: false
+search: true
+title: GraphQL Parser cache
+section: Other
+desc: How to make parsing GraphQL faster with caching
+---
+
+Parser caching may be optionally enabled by setting `config.graphql.parser_cache = true` in your Rails application. The cache may be manually built by assigning `GraphQL::Language::Parser.cache = GraphQL::Language::Cache.new("some_dir")`. This will create a directory (`tmp/cache/graphql` by default) that stores a cache of parsed files.
+
+Much like [bootsnap](https://github.com/Shopify/bootsnap), the parser cache needs to be cleaned up manually. You will need to clear the cache directory for each new deployment of your application. Also note that the parser cache will grow as your schema is loaded, so the cache directory must be writable.

lib/graphql/railtie.rb

@@ -1,12 +1,15 @@
 # frozen_string_literal: true
+
 module GraphQL
   class Railtie < Rails::Railtie
-    config.before_configuration do
-      # Bootsnap compile cache has similar expiration properties,
-      # so we assume that if the user has bootsnap setup it's ok
-      # to piggy back on it.
-      if ::Object.const_defined?("Bootsnap::CompileCache::ISeq") && Bootsnap::CompileCache::ISeq.cache_dir
-        Language::Parser.cache ||= Language::Cache.new(Pathname.new(Bootsnap::CompileCache::ISeq.cache_dir).join('graphql'))
+    config.graphql = ActiveSupport::OrderedOptions.new
+    config.graphql.parser_cache = false
+
+    initializer("graphql.cache") do |app|
+      if config.graphql.parser_cache
+        Language::Parser.cache ||= Language::Cache.new(
+          app.root.join("tmp/cache/graphql")
+        )
       end
     end
   end