Use Prism in Sorbet calls, if enabled

Author: amomchilov

lib/tapioca/helpers/sorbet_helper.rb

@@ -13,15 +13,67 @@ module SorbetHelper
 
     SPOOM_CONTEXT = Spoom::Context.new(".") #: Spoom::Context
 
+    # Represents the `sorbet/config` file, and provides access to its options.
+    # If the file doesn't exist, this object will still exist, but will return default values for all options.
+    class SorbetConfig
+      class << self
+        #: (Spoom::Context spoom_context) -> SorbetConfig
+        def parse_from(spoom_context)
+          config_path = File.join(spoom_context.absolute_path, "sorbet", "config")
+          content = File.exist?(config_path) ? File.read(config_path) : ""
+          parse(content)
+        end
+
+        #: (String content) -> SorbetConfig
+        def parse(content)
+          lines = content.lines.map(&:strip).reject(&:empty?)
+
+          options = lines.filter_map do |line|
+            next if line.start_with?("#") # Skip comments
+            next unless line.start_with?("--")
+
+            key, value = line.split("=", 2)
+            key = key #: as !nil
+
+            [key, value]
+          end.to_h #: Hash[String, String | bool | nil]
+
+          new(
+            parser: options["--parser"] == "prism" ? :prism : :original,
+          )
+        end
+      end
+
+      #: (parser: Symbol) -> void
+      def initialize(parser:)
+        @parser = parser #: Symbol
+      end
+
+      #: Symbol
+      attr_reader :parser
+
+      #: -> bool
+      def parse_with_prism? = @parser == :prism
+    end
+
     FEATURE_REQUIREMENTS = {
       # feature_name: ::Gem::Requirement.new(">= ___"), # https://github.com/sorbet/sorbet/pull/___
     }.freeze #: Hash[Symbol, ::Gem::Requirement]
 
     #: (*String sorbet_args) -> Spoom::ExecResult
     def sorbet(*sorbet_args)
+      if sorbet_config.parse_with_prism?
+        sorbet_args << "--parser=prism"
+      end
+
       SPOOM_CONTEXT.srb(sorbet_args.join(" "), sorbet_bin: sorbet_path)
     end
 
+    #: -> SorbetConfig
+    def sorbet_config
+      @sorbet_config ||= SorbetConfig.parse_from(SPOOM_CONTEXT) #: SorbetConfig?
+    end
+
     #: -> String
     def sorbet_path
       sorbet_path = ENV.fetch(SORBET_EXE_PATH_ENV_VAR, SORBET_BIN)

spec/tapioca/helpers/sorbet_helper_spec.rb

@@ -34,7 +34,74 @@ class Tapioca::SorbetHelperSpec < Minitest::Spec
     end
   end
 
-  private
+  describe Tapioca::SorbetHelper::SorbetConfig do
+    it "ignores comment lines" do
+      config = parse(<<~CONFIG)
+        # --parser=prism
+      CONFIG
+      assert_equal(:original, config.parser)
+    end
+
+    it "ignores blank lines" do
+      config = parse(<<~CONFIG)
+
+        --parser=prism
+
+      CONFIG
+      assert_equal(:prism, config.parser)
+    end
+
+    it "ignores lines without -- prefix" do
+      config = parse(<<~CONFIG)
+        .
+        src/
+        --parser=prism
+      CONFIG
+      assert_equal(:prism, config.parser)
+    end
+
+    describe "--parser" do
+      it "detects --parser=prism" do
+        config = parse(<<~CONFIG)
+          .
+          --parser=prism
+        CONFIG
+        assert_equal(:prism, config.parser)
+        assert_predicate(config, :parse_with_prism?)
+      end
+
+      it "defaults to :original for empty config" do
+        config = parse("")
+        assert_equal(:original, config.parser)
+        refute_predicate(config, :parse_with_prism?)
+      end
+
+      it "defaults to :original when no --parser option" do
+        config = parse(<<~CONFIG)
+          .
+          --dir=foo
+        CONFIG
+        assert_equal(:original, config.parser)
+      end
+
+      it "treats non-prism values as :original" do
+        config = parse(<<~CONFIG)
+          .
+          --parser=original
+        CONFIG
+        assert_equal(:original, config.parser)
+        refute_predicate(config, :parse_with_prism?)
+      end
+    end
+
+    private
+
+    #: (String content) -> Tapioca::SorbetHelper::SorbetConfig
+    def parse(content) = Tapioca::SorbetHelper::SorbetConfig.parse(content)
+  end
+
+  # Rubocop thinks the `private` call above (in the `describe` block) still applies here. It doesn't.
+  private # rubocop:disable Lint/UselessAccessModifier
 
   #: (String? path) { (String? custom_path) -> void } -> void
   def with_custom_sorbet_exe_path(path, &block)