feat: make JSON lib configurable

Currently, a mix of goccy/json and encoding/json is used. Both
use the same interface; goccy/json is faster, however, it also
does questionable things with go:linkname.
Create a common package that can be switched (via build tags)
from one implementation to another, and use that in all packages.

Author: secDre4mer

Diff for: api-bucket-notification.go

@@ -26,7 +26,7 @@ import (
 	"net/url"
 	"time"
 
-	"github.com/goccy/go-json"
+	"github.com/minio/minio-go/v7/internal/json"
 	"github.com/minio/minio-go/v7/pkg/notification"
 	"github.com/minio/minio-go/v7/pkg/s3utils"
 )

Diff for: api-bucket-replication.go

@@ -20,14 +20,14 @@ package minio
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"encoding/xml"
 	"io"
 	"net/http"
 	"net/url"
 	"time"
 
 	"github.com/google/uuid"
+	"github.com/minio/minio-go/v7/internal/json"
 	"github.com/minio/minio-go/v7/pkg/replication"
 	"github.com/minio/minio-go/v7/pkg/s3utils"
 )

Diff for: api-prompt-object.go

@@ -23,7 +23,7 @@ import (
 	"io"
 	"net/http"
 
-	"github.com/goccy/go-json"
+	"github.com/minio/minio-go/v7/internal/json"
 	"github.com/minio/minio-go/v7/pkg/s3utils"
 )
 

Diff for: api-put-object-fan-out.go

@@ -19,7 +19,6 @@ package minio
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"io"
 	"mime/multipart"
@@ -28,6 +27,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/minio/minio-go/v7/internal/json"
 	"github.com/minio/minio-go/v7/pkg/encrypt"
 )
 

Diff for: internal/json/json_goccy.go

@@ -0,0 +1,49 @@
+//go:build !stdlibjson
+
+/*
+ * MinIO Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2025 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package json
+
+import "github.com/goccy/go-json"
+
+// This file defines the JSON functions used internally and forwards them
+// to goccy/go-json. Alternatively, the standard library can be used by setting
+// the build tag stdlibjson. This can be useful for testing purposes or if
+// goccy/go-json causes issues.
+//
+// This file does not contain all definitions from goccy/go-json; if needed, more
+// can be added, but keep in mind that json_stdlib.go will also need to be
+// updated.
+
+var (
+	// Unmarshal is a wrapper around goccy/go-json Unmarshal function.
+	Unmarshal = json.Unmarshal
+	// Marshal is a wrapper around goccy/go-json Marshal function.
+	Marshal = json.Marshal
+	// NewEncoder is a wrapper around goccy/go-json NewEncoder function.
+	NewEncoder = json.NewEncoder
+	// NewDecoder is a wrapper around goccy/go-json NewDecoder function.
+	NewDecoder = json.NewDecoder
+)
+
+type (
+	// Encoder is an alias for goccy/go-json Encoder.
+	Encoder = json.Encoder
+	// Decoder is an alias for goccy/go-json Decoder.
+	Decoder = json.Decoder
+)

Diff for: internal/json/json_stdlib.go

@@ -0,0 +1,49 @@
+//go:build stdlibjson
+
+/*
+ * MinIO Go Library for Amazon S3 Compatible Cloud Storage
+ * Copyright 2025 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package json
+
+import "encoding/json"
+
+// This file defines the JSON functions used internally and forwards them
+// to encoding/json. This is only enabled by setting the build tag stdlibjson,
+// otherwise json_goccy.go applies.
+// This can be useful for testing purposes or if goccy/go-json (which is used otherwise) causes issues.
+//
+// This file does not contain all definitions from encoding/json; if needed, more
+// can be added, but keep in mind that json_goccy.go will also need to be
+// updated.
+
+var (
+	// Unmarshal is a wrapper around encoding/json Unmarshal function.
+	Unmarshal = json.Unmarshal
+	// Marshal is a wrapper around encoding/json Marshal function.
+	Marshal = json.Marshal
+	// NewEncoder is a wrapper around encoding/json NewEncoder function.
+	NewEncoder = json.NewEncoder
+	// NewDecoder is a wrapper around encoding/json NewDecoder function.
+	NewDecoder = json.NewDecoder
+)
+
+type (
+	// Encoder is an alias for encoding/json Encoder.
+	Encoder = json.Encoder
+	// Decoder is an alias for encoding/json Decoder.
+	Decoder = json.Decoder
+)

Diff for: pkg/credentials/file_aws_credentials.go

@@ -18,7 +18,6 @@
 package credentials
 
 import (
-	"encoding/json"
 	"errors"
 	"os"
 	"os/exec"
@@ -27,6 +26,7 @@ import (
 	"time"
 
 	"github.com/go-ini/ini"
+	"github.com/minio/minio-go/v7/internal/json"
 )
 
 // A externalProcessCredentials stores the output of a credential_process

Diff for: pkg/credentials/file_minio_client.go

@@ -22,7 +22,7 @@ import (
 	"path/filepath"
 	"runtime"
 
-	"github.com/goccy/go-json"
+	"github.com/minio/minio-go/v7/internal/json"
 )
 
 // A FileMinioClient retrieves credentials from the current user's home

Diff for: pkg/credentials/iam_aws.go

@@ -31,7 +31,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/goccy/go-json"
+	"github.com/minio/minio-go/v7/internal/json"
 )
 
 // DefaultExpiryWindow - Default expiry window.

Diff for: pkg/encrypt/server-side.go

@@ -23,7 +23,7 @@ import (
 	"errors"
 	"net/http"
 
-	"github.com/goccy/go-json"
+	"github.com/minio/minio-go/v7/internal/json"
 	"golang.org/x/crypto/argon2"
 )
 

Diff for: pkg/lifecycle/lifecycle.go

@@ -19,10 +19,11 @@
 package lifecycle
 
 import (
-	"encoding/json"
 	"encoding/xml"
 	"errors"
 	"time"
+
+	"github.com/minio/minio-go/v7/internal/json"
 )
 
 var errMissingStorageClass = errors.New("storage-class cannot be empty")

Diff for: pkg/lifecycle/lifecycle_test.go

@@ -19,10 +19,11 @@ package lifecycle
 
 import (
 	"bytes"
-	"encoding/json"
 	"encoding/xml"
 	"testing"
 	"time"
+
+	"github.com/minio/minio-go/v7/internal/json"
 )
 
 func TestLifecycleUnmarshalJSON(t *testing.T) {

Diff for: pkg/policy/bucket-policy-condition.go

@@ -17,7 +17,11 @@
 
 package policy
 
-import "github.com/minio/minio-go/v7/pkg/set"
+import (
+	"encoding/json"
+
+	"github.com/minio/minio-go/v7/pkg/set"
+)
 
 // ConditionKeyMap - map of policy condition key and value.
 type ConditionKeyMap map[string]set.StringSet
@@ -92,6 +96,13 @@ func (cond ConditionMap) Remove(condKey string) {
 	delete(cond, condKey)
 }
 
+// MarshalJSON is a custom json marshaler. It is needed due to
+// https://github.com/goccy/go-json/issues/543
+// and circumvents the issue by using the stdlib json package.
+func (cond ConditionMap) MarshalJSON() ([]byte, error) {
+	return json.Marshal(map[string]ConditionKeyMap(cond))
+}
+
 // mergeConditionMap - returns new ConditionMap which contains merged key/value of two ConditionMap.
 func mergeConditionMap(condMap1, condMap2 ConditionMap) ConditionMap {
 	out := make(ConditionMap)

Diff for: pkg/policy/bucket-policy-condition_test.go

@@ -42,6 +42,7 @@ func TestConditionKeyMapAdd(t *testing.T) {
 
 	for _, testCase := range testCases {
 		condKeyMap.Add(testCase.key, testCase.value)
+		// Must be encoded with stdlib json due to https://github.com/goccy/go-json/issues/543
 		if data, err := json.Marshal(condKeyMap); err != nil {
 			t.Fatalf("Unable to marshal ConditionKeyMap to JSON, %s", err)
 		} else {

Diff for: pkg/policy/bucket-policy.go

@@ -18,11 +18,12 @@
 package policy
 
 import (
-	"encoding/json"
+	stdjson "encoding/json"
 	"errors"
 	"reflect"
 	"strings"
 
+	"github.com/minio/minio-go/v7/internal/json"
 	"github.com/minio/minio-go/v7/pkg/set"
 )
 
@@ -121,6 +122,15 @@ type Statement struct {
 	Sid        string
 }
 
+// MarshalJSON is a custom json marshaler. It is needed due to
+// the error reported in https://github.com/goccy/go-json/pull/545
+// (which prevents goccy/go-json from omitting the empty Conditions field)
+// and circumvents the issue by using the stdlib json package.
+func (s Statement) MarshalJSON() ([]byte, error) {
+	type AliasStatement Statement
+	return stdjson.Marshal(AliasStatement(s))
+}
+
 // BucketAccessPolicy - minio policy collection
 type BucketAccessPolicy struct {
 	Version    string      // date in YYYY-MM-DD format

Diff for: pkg/policy/bucket-policy_test.go

@@ -18,11 +18,11 @@
 package policy
 
 import (
-	"encoding/json"
 	"fmt"
 	"reflect"
 	"testing"
 
+	"github.com/minio/minio-go/v7/internal/json"
 	"github.com/minio/minio-go/v7/pkg/set"
 )
 

Diff for: pkg/set/stringset.go

@@ -21,7 +21,7 @@ import (
 	"fmt"
 	"sort"
 
-	"github.com/goccy/go-json"
+	"github.com/minio/minio-go/v7/internal/json"
 )
 
 // StringSet - uses map as set of strings.