Ractor error tests

Author: etiennebarrie

test/ruby/test_ractor.rb

@@ -201,6 +201,50 @@ def test_max_cpu_1
     RUBY
   end
 
+  def test_error_includes_ivar_and_object
+    obj = Class.new do
+      def initialize
+        @unshareable = -> {}
+      end
+
+      def inspect
+        "#<Unshareable>"
+      end
+    end.new
+    assert_unshareable(obj, /:ivar, :@unshareable, #<Unshareable>/)
+  end
+
+  def test_error_includes_array_index
+    assert_unshareable([0, -> {}], /:array_at, 1/)
+  end
+
+  def test_error_includes_hash_key_and_value
+    assert_unshareable({ unshareable: -> {} }, /:hash_at, :unshareable, #<Proc:/)
+  end
+
+  def test_error_includes_hash_unshareable_key
+    assert_unshareable({ -> {} => true }, /:hash_key, #<Proc:0x[[:xdigit:]]+ #{__FILE__}:#{__LINE__}/)
+  end
+
+  def test_error_includes_hash_default
+    h = Hash.new {}
+    assert_unshareable(h, /:hash_default, #<Proc:0x[[:xdigit:]]+ #{__FILE__}:#{__LINE__ - 1}/)
+  end
+
+  def test_error_includes_proc_self
+    pr = -> {}
+    assert_unshareable(pr, /:proc_self, #<#{self.class.name}/)
+  end
+
+  def test_error_wraps_freeze_error
+    obj = Class.new do
+      undef_method :freeze
+    end.new
+    e = assert_unshareable(obj, /failed to call #freeze/, exception: Ractor::Error)
+    assert_equal NoMethodError, e.cause.class
+    assert_equal :freeze, e.cause.name
+  end
+
   def assert_make_shareable(obj)
     refute Ractor.shareable?(obj), "object was already shareable"
     Ractor.make_shareable(obj)
@@ -209,9 +253,10 @@ def assert_make_shareable(obj)
 
   def assert_unshareable(obj, msg=nil, exception: Ractor::IsolationError)
     refute Ractor.shareable?(obj), "object is already shareable"
-    assert_raise_with_message(exception, msg) do
+    e = assert_raise_with_message(exception, msg) do
       Ractor.make_shareable(obj)
     end
     refute Ractor.shareable?(obj), "despite raising, object became shareable"
+    e
   end
 end