Implement `respond_to?` in RubyMessage (#9677)

All synthetic methods implemented by `method_missing` are now supported by `respond_to?`.

Fixes issue #9202.

* Fix null pointer exceptions exposed by new regression tests.
* Fix clear_ on oneofs so that it is safe to call repeatedly and so that respond_to? does not depend on whether the oneof is currently cleared.
* Code cleanup: reenable more tests on JRuby.
* Align JRuby behavior with CRuby by throwing a RuntimeError when attempting to assign to a oneof.

(cherry picked from commit 8e7f936696)

ruby/src/main/java/com/google/protobuf/jruby/RubyDescriptor.java

@@ -209,6 +209,8 @@ public class RubyDescriptor extends RubyObject {
         klass.include(new IRubyObject[] {messageExts});
         klass.instance_variable_set(runtime.newString(Utils.DESCRIPTOR_INSTANCE_VAR), this);
         klass.defineAnnotatedMethods(RubyMessage.class);
+        // Workaround for https://github.com/jruby/jruby/issues/7154
+        klass.searchMethod("respond_to?").setIsBuiltin(false);
         return klass;
     }
 

ruby/src/main/java/com/google/protobuf/jruby/RubyMessage.java

@@ -260,6 +260,86 @@ public class RubyMessage extends RubyObject {
         return runtime.getTrue();
     }
 
+    /*
+     * call-seq:
+     *     Message.respond_to?(method_name, search_private_and_protected) => boolean
+     *
+     *  Parallels method_missing, returning true when this object implements a method with the given
+     *  method_name.
+     */
+    @JRubyMethod(name="respond_to?", required = 1, optional = 1)
+    public IRubyObject respondTo(ThreadContext context, IRubyObject [] args) {
+        String methodName = args[0].asJavaString();
+        if (descriptor.findFieldByName(methodName) != null) {
+            return context.runtime.getTrue();
+        }
+        RubyDescriptor rubyDescriptor = (RubyDescriptor) getDescriptor(context, metaClass);
+        IRubyObject oneofDescriptor = rubyDescriptor.lookupOneof(context, args[0]);
+        if (!oneofDescriptor.isNil()) {
+            return context.runtime.getTrue();
+        }
+        if (methodName.startsWith(CLEAR_PREFIX)) {
+            String strippedMethodName = methodName.substring(6);
+            oneofDescriptor = rubyDescriptor.lookupOneof(context, context.runtime.newSymbol(strippedMethodName));
+            if (!oneofDescriptor.isNil()) {
+                return context.runtime.getTrue();
+            }
+
+            if (descriptor.findFieldByName(strippedMethodName) != null) {
+                return context.runtime.getTrue();
+            }
+        }
+        if (methodName.startsWith(HAS_PREFIX) && methodName.endsWith(QUESTION_MARK)) {
+            String strippedMethodName = methodName.substring(4, methodName.length() - 1);
+            FieldDescriptor fieldDescriptor = descriptor.findFieldByName(strippedMethodName);
+            if (fieldDescriptor != null &&
+                (!proto3 || fieldDescriptor.getContainingOneof() == null || fieldDescriptor
+                    .getContainingOneof().isSynthetic()) &&
+                    fieldDescriptor.hasPresence()) {
+                return context.runtime.getTrue();
+            }
+            oneofDescriptor = rubyDescriptor.lookupOneof(context, RubyString.newString(context.runtime, strippedMethodName));
+            if (!oneofDescriptor.isNil()) {
+                return context.runtime.getTrue();
+            }
+        }
+        if (methodName.endsWith(AS_VALUE_SUFFIX)) {
+            FieldDescriptor fieldDescriptor = descriptor.findFieldByName(
+                methodName.substring(0, methodName.length() - 9));
+            if (fieldDescriptor != null && isWrappable(fieldDescriptor)) {
+                return context.runtime.getTrue();
+            }
+        }
+        if (methodName.endsWith(CONST_SUFFIX)) {
+            FieldDescriptor fieldDescriptor = descriptor.findFieldByName(
+                methodName.substring(0, methodName.length() - 6));
+            if (fieldDescriptor != null) {
+                if (fieldDescriptor.getType() == FieldDescriptor.Type.ENUM) {
+                    return context.runtime.getTrue();
+                }
+            }
+        }
+        if (methodName.endsWith(Utils.EQUAL_SIGN)) {
+            String strippedMethodName = methodName.substring(0, methodName.length() - 1);
+            FieldDescriptor fieldDescriptor = descriptor.findFieldByName(strippedMethodName);
+            if (fieldDescriptor != null) {
+                return context.runtime.getTrue();
+            }
+            if (strippedMethodName.endsWith(AS_VALUE_SUFFIX)) {
+                strippedMethodName = methodName.substring(0, strippedMethodName.length() - 9);
+                fieldDescriptor = descriptor.findFieldByName(strippedMethodName);
+                if (fieldDescriptor != null && isWrappable(fieldDescriptor)) {
+                    return context.runtime.getTrue();
+                }
+            }
+        }
+        boolean includePrivate = false;
+        if (args.length == 2) {
+            includePrivate = context.runtime.getTrue().equals(args[1]);
+        }
+        return metaClass.respondsToMethod(methodName, includePrivate) ? context.runtime.getTrue() : context.runtime.getFalse();
+    }
+
     /*
      * call-seq:
      *     Message.method_missing(*args)
@@ -291,10 +371,9 @@ public class RubyMessage extends RubyObject {
     public IRubyObject methodMissing(ThreadContext context, IRubyObject[] args) {
         Ruby runtime = context.runtime;
         String methodName = args[0].asJavaString();
+        RubyDescriptor rubyDescriptor = (RubyDescriptor) getDescriptor(context, metaClass);
 
         if (args.length == 1) {
-            RubyDescriptor rubyDescriptor = (RubyDescriptor) getDescriptor(context, metaClass);
-
             // If we find a Oneof return it's name (use lookupOneof because it has an index)
             IRubyObject oneofDescriptor = rubyDescriptor.lookupOneof(context, args[0]);
 
@@ -331,9 +410,12 @@ public class RubyMessage extends RubyObject {
             if (methodName.startsWith(CLEAR_PREFIX)) {
                 methodName = methodName.substring(6);
                 oneofDescriptor = rubyDescriptor.lookupOneof(context, runtime.newSymbol(methodName));
-
                 if (!oneofDescriptor.isNil()) {
                     fieldDescriptor = oneofCases.get(((RubyOneofDescriptor) oneofDescriptor).getDescriptor());
+                    if (fieldDescriptor == null) {
+                        // Clearing an already cleared oneof; return here to avoid NoMethodError.
+                        return context.nil;
+                    }
                 }
 
                 if (fieldDescriptor == null) {
@@ -379,8 +461,7 @@ public class RubyMessage extends RubyObject {
             } else if (methodName.endsWith(CONST_SUFFIX)) {
                 methodName = methodName.substring(0, methodName.length() - 6);
                 fieldDescriptor = descriptor.findFieldByName(methodName);
-
+                if (fieldDescriptor != null && fieldDescriptor.getType() == FieldDescriptor.Type.ENUM) {
-                if (fieldDescriptor.getType() == FieldDescriptor.Type.ENUM) {
                     IRubyObject enumValue = getFieldInternal(context, fieldDescriptor);
 
                     if (!enumValue.isNil()) {
@@ -404,17 +485,21 @@ public class RubyMessage extends RubyObject {
 
             methodName = methodName.substring(0, methodName.length() - 1); // Trim equals sign
             FieldDescriptor fieldDescriptor = descriptor.findFieldByName(methodName);
-
             if (fieldDescriptor != null) {
                 return setFieldInternal(context, fieldDescriptor, args[1]);
             }
 
+            IRubyObject oneofDescriptor = rubyDescriptor.lookupOneof(context, RubyString.newString(context.runtime, methodName));
+            if (!oneofDescriptor.isNil()) {
+                throw runtime.newRuntimeError("Oneof accessors are read-only.");
+            }
+
             if (methodName.endsWith(AS_VALUE_SUFFIX)) {
                 methodName = methodName.substring(0, methodName.length() - 9);
 
                 fieldDescriptor = descriptor.findFieldByName(methodName);
 
-                if (fieldDescriptor != null) {
+                if (fieldDescriptor != null && isWrappable(fieldDescriptor)) {
                     if (args[1].isNil()) {
                         return setFieldInternal(context, fieldDescriptor, args[1]);
                     }

ruby/tests/basic.rb

@@ -66,8 +66,11 @@ module BasicTest
     def test_issue_8559_crash
       msg = TestMessage.new
       msg.repeated_int32 = ::Google::Protobuf::RepeatedField.new(:int32, [1, 2, 3])
-      # TODO: Remove the platform check once https://github.com/jruby/jruby/issues/6818 is released in JRuby 9.3.0.0
+
-      GC.start(full_mark: true, immediate_sweep: true) unless RUBY_PLATFORM == "java"
+      # https://github.com/jruby/jruby/issues/6818 was fixed in JRuby 9.3.0.0
+      if cruby_or_jruby_9_3_or_higher?
+        GC.start(full_mark: true, immediate_sweep: true)
+      end
       TestMessage.encode(msg)
     end
 
@@ -99,7 +102,7 @@ module BasicTest
 
       begin
         encoded = msgclass.encode(m)
-      rescue java.lang.NullPointerException => e
+      rescue java.lang.NullPointerException
         flunk "NPE rescued"
       end
       decoded = msgclass.decode(encoded)
@@ -173,7 +176,7 @@ module BasicTest
       m = TestSingularFields.new
 
       m.singular_int32 = -42
-      assert_equal -42, m.singular_int32
+      assert_equal( -42, m.singular_int32 )
       m.clear_singular_int32
       assert_equal 0, m.singular_int32
 
@@ -568,8 +571,6 @@ module BasicTest
 
 
     def test_json_maps
-      # TODO: Fix JSON in JRuby version.
-      return if RUBY_PLATFORM == "java"
       m = MapMessage.new(:map_string_int32 => {"a" => 1})
       expected = {mapStringInt32: {a: 1}, mapStringMsg: {}, mapStringEnum: {}}
       expected_preserve = {map_string_int32: {a: 1}, map_string_msg: {}, map_string_enum: {}}
@@ -583,8 +584,6 @@ module BasicTest
     end
 
     def test_json_maps_emit_defaults_submsg
-      # TODO: Fix JSON in JRuby version.
-      return if RUBY_PLATFORM == "java"
       m = MapMessage.new(:map_string_msg => {"a" => TestMessage2.new(foo: 0)})
       expected = {mapStringInt32: {}, mapStringMsg: {a: {foo: 0}}, mapStringEnum: {}}
 
@@ -594,8 +593,6 @@ module BasicTest
     end
 
     def test_json_emit_defaults_submsg
-      # TODO: Fix JSON in JRuby version.
-      return if RUBY_PLATFORM == "java"
       m = TestSingularFields.new(singular_msg: proto_module::TestMessage2.new)
 
       expected = {
@@ -618,8 +615,6 @@ module BasicTest
     end
 
     def test_respond_to
-      # This test fails with JRuby 1.7.23, likely because of an old JRuby bug.
-      return if RUBY_PLATFORM == "java"
       msg = MapMessage.new
       assert msg.respond_to?(:map_string_int32)
       assert !msg.respond_to?(:bacon)
@@ -694,5 +689,51 @@ module BasicTest
       m2 = proto_module::TestMessage.decode(proto_module::TestMessage.encode(m))
       assert_equal m2, m
     end
+
+    def test_map_fields_respond_to? # regression test for issue 9202
+      msg = proto_module::MapMessage.new
+      assert msg.respond_to?(:map_string_int32=)
+      msg.map_string_int32 = Google::Protobuf::Map.new(:string, :int32)
+      assert msg.respond_to?(:map_string_int32)
+      assert_equal( Google::Protobuf::Map.new(:string, :int32), msg.map_string_int32 )
+      assert msg.respond_to?(:clear_map_string_int32)
+      msg.clear_map_string_int32
+
+      assert !msg.respond_to?(:has_map_string_int32?)
+      assert_raise NoMethodError do
+        msg.has_map_string_int32?
+      end
+      assert !msg.respond_to?(:map_string_int32_as_value)
+      assert_raise NoMethodError do
+        msg.map_string_int32_as_value
+      end
+      assert !msg.respond_to?(:map_string_int32_as_value=)
+      assert_raise NoMethodError do
+        msg.map_string_int32_as_value = :boom
+      end
+    end
+  end
+
+  def test_oneof_fields_respond_to? # regression test for issue 9202
+    msg = proto_module::OneofMessage.new
+    # `has_` prefix + "?" suffix actions should only work for oneofs fields.
+    assert msg.has_my_oneof?
+    assert msg.respond_to? :has_my_oneof?
+    assert !msg.respond_to?( :has_a? )
+    assert_raise NoMethodError do
+      msg.has_a?
+    end
+    assert !msg.respond_to?( :has_b? )
+    assert_raise NoMethodError do
+      msg.has_b?
+    end
+    assert !msg.respond_to?( :has_c? )
+    assert_raise NoMethodError do
+      msg.has_c?
+    end
+    assert !msg.respond_to?( :has_d? )
+    assert_raise NoMethodError do
+      msg.has_d?
+    end
   end
 end

ruby/tests/basic_proto2.rb

@@ -142,7 +142,7 @@ module BasicTestProto2
       m = TestMessageDefaults.new
 
       m.optional_int32 = -42
-      assert_equal -42, m.optional_int32
+      assert_equal( -42, m.optional_int32 )
       assert m.has_optional_int32?
       m.clear_optional_int32
       assert_equal 1, m.optional_int32
@@ -255,5 +255,20 @@ module BasicTestProto2
       assert_equal "tests/basic_test_proto2.proto", file_descriptor.name
       assert_equal :proto2, file_descriptor.syntax
     end
+
+    def test_oneof_fields_respond_to? # regression test for issue 9202
+      msg = proto_module::OneofMessage.new(a: "foo")
+      # `has_` prefix + "?" suffix actions should only work for oneofs fields.
+      assert msg.respond_to? :has_my_oneof?
+      assert msg.has_my_oneof?
+      assert msg.respond_to? :has_a?
+      assert msg.has_a?
+      assert msg.respond_to? :has_b?
+      assert !msg.has_b?
+      assert msg.respond_to? :has_c?
+      assert !msg.has_c?
+      assert msg.respond_to? :has_d?
+      assert !msg.has_d?
+    end
   end
 end

ruby/tests/common_tests.rb

@@ -796,7 +796,7 @@ module CommonTests
     m.repeated_string += %w[two three]
     assert_equal %w[one two three], m.repeated_string
 
-    m.repeated_string.push *['four', 'five']
+    m.repeated_string.push( *['four', 'five'] )
     assert_equal %w[one two three four five], m.repeated_string
 
     m.repeated_string.push 'six', 'seven'
@@ -1085,8 +1085,6 @@ module CommonTests
   end
 
   def test_json
-    # TODO: Fix JSON in JRuby version.
-    return if RUBY_PLATFORM == "java"
     m = proto_module::TestMessage.new(:optional_int32 => 1234,
                                       :optional_int64 => -0x1_0000_0000,
                                       :optional_uint32 => 0x8000_0000,
@@ -1288,6 +1286,7 @@ module CommonTests
     m2 = proto_module::Wrapper.decode(m.to_proto)
     run_asserts.call(m2)
     m3 = proto_module::Wrapper.decode_json(m.to_json)
+    run_asserts.call(m3)
   end
 
   def test_wrapper_getters
@@ -1539,8 +1538,6 @@ module CommonTests
       assert_nil m.bytes_as_value
     }
 
-    m = proto_module::Wrapper.new
-
     m2 = proto_module::Wrapper.new(
       double: Google::Protobuf::DoubleValue.new(value: 2.0),
       float: Google::Protobuf::FloatValue.new(value: 4.0),
@@ -1787,27 +1784,200 @@ module CommonTests
     assert_nil h[m2]
   end
 
+  def cruby_or_jruby_9_3_or_higher?
+    # https://github.com/jruby/jruby/issues/6818 was fixed in JRuby 9.3.0.0
+    match = RUBY_PLATFORM == "java" &&
+      JRUBY_VERSION.match(/^(\d+)\.(\d+)\.\d+\.\d+$/)
+    match && (match[1].to_i > 9 || (match[1].to_i == 9 && match[2].to_i >= 3))
+  end
+
   def test_object_gc
     m = proto_module::TestMessage.new(optional_msg: proto_module::TestMessage2.new)
     m.optional_msg
-    # TODO: Remove the platform check once https://github.com/jruby/jruby/issues/6818 is released in JRuby 9.3.0.0
+    # https://github.com/jruby/jruby/issues/6818 was fixed in JRuby 9.3.0.0
-    GC.start(full_mark: true, immediate_sweep: true) unless RUBY_PLATFORM == "java"
+    GC.start(full_mark: true, immediate_sweep: true) if cruby_or_jruby_9_3_or_higher?
     m.optional_msg.inspect
   end
 
   def test_object_gc_freeze
     m = proto_module::TestMessage.new
     m.repeated_float.freeze
-    # TODO: Remove the platform check once https://github.com/jruby/jruby/issues/6818 is released in JRuby 9.3.0.0
+    # https://github.com/jruby/jruby/issues/6818 was fixed in JRuby 9.3.0.0
-    GC.start(full_mark: true) unless RUBY_PLATFORM == "java"
+    GC.start(full_mark: true) if cruby_or_jruby_9_3_or_higher?
 
     # Make sure we remember that the object is frozen.
     # The wrapper object contains this information, so we need to ensure that
     # the previous GC did not collect it.
     assert m.repeated_float.frozen?
 
-    # TODO: Remove the platform check once https://github.com/jruby/jruby/issues/6818 is released in JRuby 9.3.0.0
+    # https://github.com/jruby/jruby/issues/6818 was fixed in JRuby 9.3.0.0
-    GC.start(full_mark: true, immediate_sweep: true) unless RUBY_PLATFORM == "java"
+    GC.start(full_mark: true, immediate_sweep: true) if cruby_or_jruby_9_3_or_higher?
     assert m.repeated_float.frozen?
   end
+
+  def test_optional_fields_respond_to? # regression test for issue 9202
+    msg = proto_module::TestMessage.new
+    assert msg.respond_to? :optional_int32=
+    msg.optional_int32 = 42
+
+    assert msg.respond_to? :optional_int32
+    assert_equal 42, msg.optional_int32
+
+    assert msg.respond_to? :clear_optional_int32
+    msg.clear_optional_int32
+    assert_equal 0, msg.optional_int32
+
+    assert msg.respond_to? :has_optional_int32?
+    assert !msg.has_optional_int32?
+
+    assert !msg.respond_to?( :optional_int32_as_value= )
+    assert_raise NoMethodError do
+      msg.optional_int32_as_value = 42
+    end
+
+    assert !msg.respond_to?( :optional_int32_as_value )
+    assert_raise NoMethodError do
+      msg.optional_int32_as_value
+    end
+
+    assert msg.respond_to? :optional_enum_const
+    assert_equal 0, msg.optional_enum_const
+
+    assert !msg.respond_to?( :foo )
+    assert_raise NoMethodError do
+      msg.foo
+    end
+
+    assert !msg.respond_to?( :foo_const )
+    assert_raise NoMethodError do
+      msg.foo_const
+    end
+
+    assert !msg.respond_to?( :optional_int32_const )
+    assert_raise NoMethodError do
+      msg.optional_int32_const
+    end
+  end
+
+  def test_oneof_fields_respond_to? # regression test for issue 9202
+    msg = proto_module::OneofMessage.new
+
+    # names of the elements of a oneof and the oneof itself are valid actions.
+    assert msg.respond_to? :my_oneof
+    assert_nil msg.my_oneof
+    assert msg.respond_to? :a
+    assert_equal "", msg.a
+    assert msg.respond_to? :b
+    assert_equal 0, msg.b
+    assert msg.respond_to? :c
+    assert_nil msg.c
+    assert msg.respond_to? :d
+    assert_equal :Default, msg.d
+
+    # `clear` prefix actions work on elements of a oneof and the oneof itself.
+    assert msg.respond_to? :clear_my_oneof
+    msg.clear_my_oneof
+    # Repeatedly clearing a oneof used to cause a NoMethodError under JRuby
+    msg.clear_my_oneof
+    assert msg.respond_to? :clear_a
+    msg.clear_a
+    assert msg.respond_to? :clear_b
+    msg.clear_b
+    assert msg.respond_to? :clear_c
+    msg.clear_c
+    assert msg.respond_to? :clear_d
+    msg.clear_d
+
+    # `=` suffix actions should work on elements of a oneof but not the oneof itself.
+    assert !msg.respond_to?( :my_oneof= )
+    error = assert_raise RuntimeError do
+      msg.my_oneof = nil
+    end
+    assert_equal "Oneof accessors are read-only.", error.message
+    assert msg.respond_to? :a=
+    msg.a = "foo"
+    assert msg.respond_to? :b=
+    msg.b = 42
+    assert msg.respond_to? :c=
+    msg.c = proto_module::TestMessage2.new
+    assert msg.respond_to? :d=
+    msg.d = :Default
+
+    # `has_` prefix + "?" suffix actions work for oneofs fields.
+    assert msg.respond_to? :has_my_oneof?
+    assert msg.has_my_oneof?
+
+    # `_as_value` suffix actions should only work for wrapped fields.
+    assert !msg.respond_to?( :my_oneof_as_value )
+    assert_raise NoMethodError do
+      msg.my_oneof_as_value
+    end
+    assert !msg.respond_to?( :a_as_value )
+    assert_raise NoMethodError do
+      msg.a_as_value
+    end
+    assert !msg.respond_to?( :b_as_value )
+    assert_raise NoMethodError do
+      msg.b_as_value
+    end
+    assert !msg.respond_to?( :c_as_value )
+    assert_raise NoMethodError do
+      msg.c_as_value
+    end
+    assert !msg.respond_to?( :d_as_value )
+    assert_raise NoMethodError do
+      msg.d_as_value
+    end
+
+    # `_as_value=` suffix actions should only work for wrapped fields.
+    assert !msg.respond_to?( :my_oneof_as_value= )
+    assert_raise NoMethodError do
+      msg.my_oneof_as_value = :boom
+    end
+    assert !msg.respond_to?( :a_as_value= )
+    assert_raise NoMethodError do
+      msg.a_as_value = ""
+    end
+    assert !msg.respond_to?( :b_as_value= )
+    assert_raise NoMethodError do
+      msg.b_as_value = 42
+    end
+    assert !msg.respond_to?( :c_as_value= )
+    assert_raise NoMethodError do
+      msg.c_as_value = proto_module::TestMessage2.new
+    end
+    assert !msg.respond_to?( :d_as_value= )
+    assert_raise NoMethodError do
+      msg.d_as_value = :Default
+    end
+
+    # `_const` suffix actions should only work for enum fields.
+    assert !msg.respond_to?( :my_oneof_const )
+    assert_raise NoMethodError do
+      msg.my_oneof_const
+    end
+    assert !msg.respond_to?( :a_const )
+    assert_raise NoMethodError do
+      msg.a_const
+    end
+    assert !msg.respond_to?( :b_const )
+    assert_raise NoMethodError do
+      msg.b_const
+    end
+    assert !msg.respond_to?( :c_const )
+    assert_raise NoMethodError do
+      msg.c_const
+    end
+    assert msg.respond_to? :d_const
+    assert_equal 0, msg.d_const
+  end
+
+  def test_wrapped_fields_respond_to? # regression test for issue 9202
+    msg = proto_module::Wrapper.new
+    assert msg.respond_to?( :double_as_value= )
+    msg.double_as_value = 42
+    assert msg.respond_to?( :double_as_value )
+    assert_equal 42, msg.double_as_value
+    assert_equal Google::Protobuf::DoubleValue.new(value: 42), msg.double
+  end
 end