add post synvert-now-supports-the-prism-parser

_posts/2024-06-13-synvert-now-supports-the-prism-parser.md

@@ -0,0 +1,51 @@
+---
+layout: default
+title: Synvert now supports the Prism parser
+date: 2024-06-13
+categories: ruby
+permalink: /:categories/:title/index.html
+---
+
+Ruby 3.3 introduced a new standard library, [Prism](https://github.com/ruby/prism), a parser for the Ruby language. Prism is designed for portability, error tolerance, and maintainability.
+
+I have integrated the Prism parser into Synvert using the Adapter pattern in the [node-query](https://github.com/synvert-hq/node-query-ruby) and [node-mutation](https://github.com/synvert-hq/node-mutation-ruby) gems. This involved implementing a Prism parser adapter, which was straightforward due to the flexible design of these gems.
+
+The Prism adapter for node-query is available here: [https://github.com/synvert-hq/node-query-ruby/blob/main/lib/node_query/adapter/prism.rb](https://github.com/synvert-hq/node-query-ruby/blob/main/lib/node_query/adapter/prism.rb). It implements methods `is_node?`, `get_node_type`, `get_source`, `get_children`, `get_siblings`.
+
+The Prism adapter for node-mutation can be found here: [https://github.com/synvert-hq/node-mutation-ruby/blob/main/lib/node_mutation/adapter/prism.rb](https://github.com/synvert-hq/node-mutation-ruby/blob/main/lib/node_mutation/adapter/prism.rb). This adapter includes methods `get_source`, `rewritten_source`, `file_source`, `child_node_range`, `get_start`, `get_end`, `get_start_loc`, `get_end_loc`.
+
+In synvert-core, I simply added a `PRISM_PARSER` constant for parser configuration. When a snippet uses the `PRISM_PARSER`, it utilizes Prism to parse the source code and pass the AST nodes to node-query and node-mutation.
+
+```ruby
+Synvert::Rewriter.new 'group', 'name' do
+  configure(parser: Synvert::PRISM_PARSER)
+end
+```
+
+For example, the `ruby/map_and_flatten_to_flat_map` snippet is using the `PARSER_PARSER`, let's rewrite it to use the `PRISM_PARSER`. If you are unfamiliar with Prism AST nodes, you can use the [Synvert Playground](https://playground.synvert.net/ruby/generate-snippet) to generate snippets with the Prism parser.
+
+```ruby
+# frozen_string_literal: true
+
+Synvert::Rewriter.new 'ruby', 'map_and_flatten_to_flat_map' do
+  configure(parser: Synvert::PRISM_PARSER)
+
+  within_files Synvert::ALL_RUBY_FILES + Synvert::ALL_RAKE_FILES do
+    # enum.map do |item|
+    #   # do something
+    # end.flatten
+    # =>
+    # enum.flat_map do |item|
+    #   # do something
+    # end
+    find_node '.call_node[receiver=.call_node[name=map][arguments=nil][block=.block_node]][name=flatten][arguments=nil]' do
+      group do
+        delete :call_operator, :name
+        replace 'receiver.name', with: 'flat_map'
+      end
+    end
+  end
+end
+```
+
+Run the test command `bundle exec rspec spec/ruby/map_and_flatten_to_flat_map_spec.rb` to ensure the snippet functions as expected.