Refactor generating gem rbis with git diff

lib/ruby_lsp/tapioca/addon.rb

@@ -19,8 +19,6 @@ module Tapioca
     class Addon < ::RubyLsp::Addon
       extend T::Sig
 
-      GEMFILE_LOCK_SNAPSHOT = "tmp/tapioca/.gemfile_lock_snapshot"
-
       sig { void }
       def initialize
         super
@@ -29,6 +27,7 @@ def initialize
         @rails_runner_client = T.let(nil, T.nilable(RubyLsp::Rails::RunnerClient))
         @index = T.let(nil, T.nilable(RubyIndexer::Index))
         @file_checksums = T.let({}, T::Hash[String, String])
+        @lockfile_diff = T.let(nil, T.nilable(String))
       end
 
       sig { override.params(global_state: RubyLsp::GlobalState, outgoing_queue: Thread::Queue).void }
@@ -47,7 +46,7 @@ def activate(global_state, outgoing_queue)
           outgoing_queue << Notification.window_log_message("Activating Tapioca add-on v#{version}")
           @rails_runner_client.register_server_addon(File.expand_path("server_addon.rb", __dir__))
 
-          generate_gem_rbis if lockfile_changed?
+          generate_gem_rbis if git_repo? && lockfile_changed?
         rescue IncompatibleApiError
           # The requested version for the Rails add-on no longer matches. We need to upgrade and fix the breaking
           # changes
@@ -113,36 +112,28 @@ def workspace_did_change_watched_files(changes)
 
       private
 
+      sig { returns(T::Boolean) }
+      def git_repo?
+        Dir.exist?(".git")
+      end
+
       sig { returns(T::Boolean) }
       def lockfile_changed?
-        return false unless Dir.exist?(".git")
+        !fetch_lockfile_diff.empty?
+      end
 
-        gemfile_status = %x(git status --porcelain Gemfile.lock).strip
-        !gemfile_status.empty?
+      sig { returns(String) }
+      def fetch_lockfile_diff
+        @lockfile_diff = %x(git diff HEAD Gemfile.lock).strip
       end
 
       sig { void }
       def generate_gem_rbis
-        current_lockfile = File.read("Gemfile.lock")
-        snapshot_lockfile = File.read(GEMFILE_LOCK_SNAPSHOT) if File.exist?(GEMFILE_LOCK_SNAPSHOT)
-
-        unless snapshot_lockfile
-          $stdout.puts("Creating initial Gemfile.lock snapshot at #{GEMFILE_LOCK_SNAPSHOT}")
-          FileUtils.mkdir_p(File.dirname(GEMFILE_LOCK_SNAPSHOT))
-          File.write(GEMFILE_LOCK_SNAPSHOT, current_lockfile)
-          return
-        end
-
-        return if current_lockfile == snapshot_lockfile
-
         T.must(@rails_runner_client).delegate_notification(
           server_addon_name: "Tapioca",
           request_name: "gem",
-          snapshot_lockfile: snapshot_lockfile,
-          current_lockfile: current_lockfile,
+          diff: T.must(@lockfile_diff),
         )
-
-        File.write(GEMFILE_LOCK_SNAPSHOT, current_lockfile)
       end
     end
   end

lib/ruby_lsp/tapioca/lockfile_diff_parser.rb

@@ -0,0 +1,44 @@
+# typed: true
+# frozen_string_literal: true
+
+module RubyLsp
+  module Tapioca
+    class LockfileDiffParser
+      GEM_PATTERN = /[+-](.*[\w\-]+)\s*\(/
+      ADDED_LINE_PATTERN = /^\+.*[\w\-]+ \(.*\)/
+      REMOVED_LINE_PATTERN = /^-.*[\w\-]+ \(.*\)/
+
+      attr_reader :added_or_modified_gems
+      attr_reader :removed_gems
+
+      def initialize(diff_content)
+        @diff_content = diff_content
+        @added_or_modified_gems = parse_added_or_modified_gems
+        @removed_gems = parse_removed_gems
+      end
+
+      private
+
+      def parse_added_or_modified_gems
+        @diff_content
+          .lines
+          .filter { |line| line.match?(ADDED_LINE_PATTERN) }
+          .map { |line| extract_gem(line) }
+          .uniq
+      end
+
+      def parse_removed_gems
+        @diff_content
+          .lines
+          .filter { |line| line.match?(REMOVED_LINE_PATTERN) }
+          .map { |line| extract_gem(line) }
+          .reject { |gem| @added_or_modified_gems.include?(gem) }
+          .uniq
+      end
+
+      def extract_gem(line)
+        line.match(GEM_PATTERN)[1].strip
+      end
+    end
+  end
+end

lib/ruby_lsp/tapioca/server_addon.rb

@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 
 require "tapioca/internal"
+require_relative "lockfile_diff_parser"
 
 module RubyLsp
   module Tapioca
@@ -27,32 +28,23 @@ def dsl(params)
       end
 
       def gem(params)
-        snapshot_specs = parse_lockfile(params[:snapshot_lockfile])
-        current_specs = parse_lockfile(params[:current_lockfile])
+        gem_changes = LockfileDiffParser.new(params[:diff])
 
-        removed_gems = snapshot_specs.keys - current_specs.keys
-        changed_gems = current_specs.select { |name, version| snapshot_specs[name] != version }.keys
-
-        return $stdout.puts("No gem changes detected") if removed_gems.empty? && changed_gems.empty?
+        removed_gems = gem_changes.removed_gems
+        added_or_modified_gems = gem_changes.added_or_modified_gems
 
         if removed_gems.any?
           $stdout.puts("Removing RBIs for deleted gems: #{removed_gems.join(", ")}")
           FileUtils.rm_f(Dir.glob("sorbet/rbi/gems/{#{removed_gems.join(",")}}@*.rbi"))
         end
 
-        if changed_gems.any?
-          $stdout.puts("Generating RBIs for changed gems: #{changed_gems.join(", ")}")
+        if added_or_modified_gems.any?
+          $stdout.puts("Generating RBIs for added or modified gems: #{added_or_modified_gems.join(", ")}")
 
           load("tapioca/cli.rb") # Reload the CLI to reset thor defaults between requests
-          ::Tapioca::Cli.start(["gem"] + changed_gems)
+          ::Tapioca::Cli.start(["gem"] + added_or_modified_gems)
         end
       end
-
-      def parse_lockfile(content)
-        return {} if content.to_s.empty?
-
-        Bundler::LockfileParser.new(content).specs.to_h { |spec| [spec.name, spec.version.to_s] }
-      end
     end
   end
 end