Add three conformance test edge cases for ProtoJSON repr of Any

1) An Any with no type_url or value should be represented as `{}`
2) A `null` should be handled as the Any being absent.
3) JSON of `{"@type_url": "", "value":""}` should be a parse failure.

PiperOrigin-RevId: 712938072

conformance/binary_json_conformance_suite.cc

@@ -3524,6 +3524,40 @@ void BinaryAndJsonConformanceSuiteImpl<MessageType>::RunJsonTestsForAny() {
     }
   }
       )");
+  // When the Any is in WKT form (with "@type"), the type_url must be present
+  // and URL shaped, otherwise it should be a parse error (because it can't be
+  // parsed into the Any schema).
+  ExpectParseFailureForJson("AnyWktRepresentationWithEmptyTypeAndValue",
+                            REQUIRED,
+                            R"({
+        "optionalAny": {
+          "@type": "",
+          "value": ""
+        }
+      })");
+  ExpectParseFailureForJson("AnyWktRepresentationWithBadType", REQUIRED,
+                            R"({
+        "optionalAny": {
+          "@type": "not_a_url",
+          "value": ""
+        }
+      })");
+  // When the Any can be parsed as non-WKT form, the type_url could be missing
+  // or invalid, since that can still be parsed into the Any schema.
+  RunValidJsonTest("AnyWithNoType", REQUIRED,
+                   R"({
+        "optionalAny": {}
+      })",
+                   R"(
+        optional_any: {}
+      )");
+  // `null` where an Any exists should just result in the field being unset.
+  RunValidJsonTest("AnyNull", REQUIRED,
+                   R"({
+        "optionalAny": null
+      })",
+                   R"(
+      )");
 }
 
 template <typename MessageType>

conformance/failure_list_csharp.txt

@@ -33,3 +33,7 @@ Recommended.Editions_Proto3.ValueRejectInfNumberValue.JsonOutput
 Recommended.Editions_Proto3.ValueRejectNanNumberValue.JsonOutput
 Required.Editions_Proto2.ProtobufInput.UnknownOrdering.ProtobufOutput
 Required.Editions_Proto3.ProtobufInput.UnknownOrdering.ProtobufOutput
+Required.*.JsonInput.AnyWithNoType.* # Failed to parse input or produce output.
+Required.*.JsonInput.AnyWktRepresentationWithEmptyTypeAndValue # Should have failed to parse, but didn't.
+Required.*.JsonInput.AnyWktRepresentationWithBadType # Should have failed to parse, but didn't.
+

conformance/failure_list_jruby.txt

@@ -144,3 +144,4 @@ Required.Editions_Proto2.ProtobufInput.UnknownOrdering.ProtobufOutput
 Required.Editions_Proto3.ProtobufInput.UnknownOrdering.ProtobufOutput
 Required.Proto2.ProtobufInput.UnknownOrdering.ProtobufOutput
 Required.Proto3.ProtobufInput.UnknownOrdering.ProtobufOutput
+Required.*.JsonInput.AnyWithNoType.JsonOutput # Failed to parse input or produce output.

conformance/failure_list_jruby_ffi.txt

@@ -1 +1,2 @@
 Required.*.JsonInput.Int32FieldQuotedExponentialValue.*     # Failed to parse input or produce output.
+Required.*.JsonInput.AnyWithNoType.* # Failed to parse input or produce output.

conformance/failure_list_php.txt

@@ -31,3 +31,4 @@ Required.*.ProtobufInput.ValidDataRepeated.FLOAT.PackedInput.JsonOutput
 Required.*.ProtobufInput.ValidDataRepeated.FLOAT.UnpackedInput.JsonOutput
 Required.*.ProtobufInput.ValidDataScalar.FLOAT[2].JsonOutput
 Required.*.JsonInput.Int32FieldQuotedExponentialValue.*     # Failed to parse input or produce output.
+Required.*.JsonInput.AnyWithNoType.*

conformance/failure_list_php_c.txt

@@ -7,3 +7,4 @@ Required.Proto2.JsonInput.EnumField.ProtobufOutput
 Required.Proto2.JsonInput.EnumFieldNumericValueZero.JsonOutput
 Required.Proto2.JsonInput.EnumFieldNumericValueZero.ProtobufOutput
 Required.Proto2.JsonInput.StoresDefaultPrimitive.Validator
+Required.*.JsonInput.AnyWithNoType.*

conformance/failure_list_ruby.txt

@@ -1 +1,2 @@
 Required.*.JsonInput.Int32FieldQuotedExponentialValue.*     # Failed to parse input or produce output.
+Required.*.JsonInput.AnyWithNoType.*

upb/conformance/conformance_upb_failures.txt

@@ -1 +1,2 @@
 Required.*.JsonInput.Int32FieldQuotedExponentialValue.*     # Failed to parse input or produce output.
+Required.*.JsonInput.AnyWithNoType.* # Failed to parse input or produce output.