Add prototype for custom test reporter for minitest

lib/minitest/reporters/ruby_lsp_reporter.rb

@@ -0,0 +1,96 @@
+# typed: strict
+# frozen_string_literal: true
+
+require "ruby_lsp/test_reporting"
+
+module Minitest
+  module Reporters
+    class RubyLspReporter < ::Minitest::Reporters::BaseReporter
+      extend T::Sig
+
+      sig { void }
+      def initialize
+        @reporting = T.let(RubyLsp::TestReporter.new, RubyLsp::TestReporter)
+        super
+      end
+
+      sig { params(test: Minitest::Test).void }
+      def before_test(test)
+        @reporting.before_test(
+          id: id_from_test(test),
+          file: file_for_class_name(test),
+        )
+        super
+      end
+
+      sig { params(test: Minitest::Test).void }
+      def after_test(test)
+        @reporting.after_test(
+          id: id_from_test(test),
+          file: file_for_class_name(test),
+        )
+        super
+      end
+
+      sig { params(test: Minitest::Result).void }
+      def record(test)
+        super
+
+        if test.passed?
+          record_pass(test)
+        elsif test.skipped?
+          record_skip(test)
+        elsif test.failure
+          record_fail(test)
+        end
+      end
+
+      sig { params(result: Minitest::Result).void }
+      def record_pass(result)
+        info = {
+          id: id_from_result(result),
+          file: result.source_location[0],
+        }
+        @reporting.record_pass(**info)
+      end
+
+      sig { params(result: Minitest::Result).void }
+      def record_skip(result)
+        info = {
+          id: id_from_result(result),
+          message: result.failure.message,
+          file: result.source_location[0],
+        }
+        @reporting.record_skip(**info)
+      end
+
+      sig { params(result: Minitest::Result).void }
+      def record_fail(result)
+        info = {
+          id: id_from_result(result),
+          type: result.failure.class.name,
+          message: result.failure.message,
+          file: result.source_location[0],
+        }
+        @reporting.record_fail(**info)
+      end
+
+      private
+
+      sig { params(test: Minitest::Test).returns(String) }
+      def id_from_test(test)
+        [test.class.name, test.name].join("#")
+      end
+
+      sig { params(result: Minitest::Result).returns(String) }
+      def id_from_result(result)
+        [result.name, result.klass].join("#")
+      end
+
+      sig { params(test: Minitest::Test).returns(String) }
+      def file_for_class_name(test)
+        T.must(Kernel.const_source_location(test.class_name)).first
+      end
+    end
+  end
+end

lib/ruby_lsp/test_reporting.rb

@@ -0,0 +1,80 @@
+# typed: strict
+# frozen_string_literal: true
+
+require "json"
+
+module RubyLsp
+  class TestReporter
+    extend T::Sig
+
+    sig { params(io: IO).void }
+    def initialize(io: $stdout)
+      @io = io
+    end
+
+    sig { params(id: String, file: String).void }
+    def before_test(id:, file:)
+      result = {
+        event: "before_test",
+        id: id,
+        file: file,
+      }
+      io.puts result.to_json
+    end
+
+    sig { params(id: String, file: String).void }
+    def after_test(id:, file:)
+      result = {
+        event: "after_test",
+        id: id,
+        file: file,
+      }
+      io.puts result.to_json
+    end
+
+    sig { params(id: String, file: String).void }
+    def record_pass(id:, file:)
+      result = {
+        event: "pass",
+        id: id,
+        file: file,
+      }
+      io.puts result.to_json
+    end
+
+    sig do
+      params(
+        id: String,
+        type: T.untyped, # TODO: what type should this be?
+        message: String,
+        file: String,
+      ).void
+    end
+    def record_fail(id:, type:, message:, file:)
+      result = {
+        event: "fail",
+        type: type,
+        message: message,
+        id: id,
+        file: file,
+      }
+      io.puts result.to_json
+    end
+
+    sig { params(id: String, message: T.nilable(String), file: String).void }
+    def record_skip(id:, message:, file:)
+      result = {
+        event: "skip",
+        message: message,
+        id: id,
+        file: file,
+      }
+      io.puts result.to_json
+    end
+
+    private
+
+    sig { returns(IO) }
+    attr_reader :io
+  end
+end

test/test_helper.rb

@@ -42,6 +42,12 @@
 end
 Minitest::Reporters.use!(minitest_reporter)
 
+# Temporary for verification
+if ENV["RUBY_LSP"]
+  require "minitest/reporters/ruby_lsp_reporter"
+  Minitest::Reporters.use!(Minitest::Reporters::RubyLspReporter.new)
+end
+
 module Minitest
   class Test
     extend T::Sig