Move diff_test.go to v1

The diff_test.go suite of tests check for expected differences
between v1 and v2. In some ways, they are higher fidelity tests
for v1 behavior than the v1 tests themselves.

Modify diff_test.go to use the emulated v1 implementation
and skip the tests are currently failing.

diff_test.go → v1/diff_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package json_test
+package json
 
 import (
 	"errors"
@@ -13,8 +13,6 @@ import (
 	"testing"
 	"time"
 
-	jsonv1 "encoding/json"
-
 	jsonv2 "github.com/go-json-experiment/json"
 )
 
@@ -27,7 +25,7 @@ var jsonPackages = []struct {
 	Marshal   func(any) ([]byte, error)
 	Unmarshal func([]byte, any) error
 }{
-	{"v1", jsonv1.Marshal, jsonv1.Unmarshal},
+	{"v1", Marshal, Unmarshal},
 	{"v2",
 		func(in any) ([]byte, error) { return jsonv2.Marshal(in) },
 		func(in []byte, out any) error { return jsonv2.Unmarshal(in, out) }},
@@ -367,6 +365,7 @@ func TestStringOption(t *testing.T) {
 
 	for _, json := range jsonPackages {
 		t.Run(path.Join("Unmarshal/Null", json.Version), func(t *testing.T) {
+			skipKnownFailure(t)
 			var got Types
 			err := json.Unmarshal([]byte(`{
 				"Bool":     "null",
@@ -416,6 +415,7 @@ func TestStringOption(t *testing.T) {
 		})
 
 		t.Run(path.Join("Unmarshal/Deep", json.Version), func(t *testing.T) {
+			skipKnownFailure(t)
 			var got Types
 			want := map[string]Types{
 				"v1": {
@@ -631,6 +631,7 @@ func TestPointerReceiver(t *testing.T) {
 
 	for _, json := range jsonPackages {
 		t.Run(path.Join("Marshal", json.Version), func(t *testing.T) {
+			skipKnownFailure(t)
 			var cc CallCheck
 			in := Values{
 				S: []CallCheck{cc},
@@ -655,6 +656,7 @@ func TestPointerReceiver(t *testing.T) {
 
 	for _, json := range jsonPackages {
 		t.Run(path.Join("Unmarshal", json.Version), func(t *testing.T) {
+			skipKnownFailure(t)
 			in := `{"S":[""],"A":[""],"M":{"":""},"V":"","I":""}`
 			called := CallCheck("CALLED") // resulting state if UnmarshalJSON is called
 			want := map[string]Values{
@@ -881,6 +883,7 @@ func TestMergeNull(t *testing.T) {
 
 	for _, json := range jsonPackages {
 		t.Run(path.Join("Unmarshal", json.Version), func(t *testing.T) {
+			skipKnownFailure(t)
 			// Start with a non-empty value where all fields are populated.
 			in := Types{
 				Bool:      true,
@@ -960,6 +963,7 @@ func TestMergeComposite(t *testing.T) {
 
 	for _, json := range jsonPackages {
 		t.Run(path.Join("Unmarshal", json.Version), func(t *testing.T) {
+			skipKnownFailure(t)
 			// Start with a non-empty value where all fields are populated.
 			in := Composites{
 				Slice:            []Tuple{{Old: true}, {Old: true}}[:1],

v1/failing.txt

@@ -24,3 +24,13 @@ TestNilMarshalerTextMapKey
 TestEncoderSetEscapeHTML
 TestEncoderSetEscapeHTML/stringOption
 TestRawMessage
+TestStringOption
+TestStringOption/Unmarshal/Null/v1
+TestStringOption/Unmarshal/Deep/v1
+TestPointerReceiver
+TestPointerReceiver/Marshal/v1
+TestPointerReceiver/Unmarshal/v1
+TestMergeNull
+TestMergeNull/Unmarshal/v1
+TestMergeComposite
+TestMergeComposite/Unmarshal/v1