Graceful (??) error handling with undefined outer module

lib/steep/services/type_check_service.rb

@@ -335,6 +335,9 @@ def type_check_file(target:, subtyping:, path:, text:)
         SourceFile.with_syntax_error(path: path, content: text, error: error)
       rescue EncodingError => exn
         SourceFile.no_data(path: path, content: "")
+      rescue RuntimeError => exn
+        Steep.log_error(exn)
+        SourceFile.no_data(path: path, content: text)
       end
 
       def self.type_check(source:, subtyping:)

test/type_check_service_test.rb

@@ -474,4 +474,32 @@ def foo: () -> B
       reported_diagnostics.clear
     end
   end
+
+  def test_signature_error_unknown_outer_module
+    # Recovering from syntax error test
+    service = Services::TypeCheckService.new(project: project)
+
+    {
+      Pathname("lib.rbs") => [ContentChange.string(<<RBS)],
+class Foo::Bar::Baz
+end
+RBS
+      Pathname("lib/a.rb") => [ContentChange.string(<<RUBY)],
+1+2
+RUBY
+    }.tap do |changes|
+      service.update_and_check(changes: changes, assignment: assignment, &reporter)
+
+      reported_diagnostics[Pathname("lib.rbs")].tap do |errors|
+        assert_any!(errors, size: 1) do |error|
+          assert_equal "RBS::UnknownTypeName", error[:code]
+          assert_equal "Cannot find type `::Foo::Bar`", error[:message]
+        end
+      end
+
+      reported_diagnostics[Pathname("lib/a.rb")].tap do |errors|
+        assert_empty errors
+      end
+    end
+  end
 end