🚀 feat: add custom definition for a json executor

app.go

@@ -270,6 +270,13 @@ type Config struct {
 	//
 	// Default: false
 	// RedirectFixedPath bool
+
+	// When set by an external client of Fiber it will use the provided implementation of a
+	// JSONExectuor
+	//
+	// Allowing for flexibility in using another json library for marshalling/unmarshalling
+	// Default: utils.DefaultJSONExecutor
+	JSONEngineExecutor utils.JSONExecutor `json:"-"`
 }
 
 // Static defines configuration options when defining static assets.
@@ -378,6 +385,9 @@ func New(config ...Config) *App {
 	if app.config.ErrorHandler == nil {
 		app.config.ErrorHandler = DefaultErrorHandler
 	}
+	if app.config.JSONEngineExecutor == nil {
+		app.config.JSONEngineExecutor = &utils.DefaultJSONExecutor{}
+	}
 
 	// Init app
 	app.init()

ctx.go

@@ -536,7 +536,7 @@ func (c *Ctx) Is(extension string) bool {
 // and a nil slice encodes as the null JSON value.
 // This method also sets the content header to application/json.
 func (c *Ctx) JSON(data interface{}) error {
-	raw, err := json.Marshal(data)
+	raw, err := c.app.config.JSONEngineExecutor.Marshal(data)
 	if err != nil {
 		return err
 	}

utils/json_executor.go

@@ -0,0 +1,21 @@
+package utils
+
+import (
+	"encoding/json"
+)
+
+// JSONExecutor provides the minimal API for basic JSON engine functionality
+type JSONExecutor interface {
+	Marshal(interface{}) ([]byte, error)
+}
+
+// DefaultJSONExecutor is a blank structure, in place to satisfy the API
+// of a JSONExecutor
+type DefaultJSONExecutor struct {
+}
+
+// Marshal takes in an arbitrary interface and returns an encoding of
+// the provided interface
+func (d *DefaultJSONExecutor) Marshal(v interface{}) ([]byte, error) {
+	return json.Marshal(v)
+}

utils/json_executor_test.go

@@ -0,0 +1,25 @@
+package utils
+
+import (
+	"testing"
+)
+
+func TestDefaultJSONExecutor(t *testing.T) {
+	type SampleStructure struct {
+		ImportantString string `json:"important_string"`
+	}
+
+	var (
+		sampleStructure = &SampleStructure{
+			ImportantString: "Hello World",
+		}
+		importantString = `{"important_string":"Hello World"}`
+	)
+
+	jsonExecutor := DefaultJSONExecutor{}
+
+	raw, err := jsonExecutor.Marshal(sampleStructure)
+	AssertEqual(t, err, nil)
+
+	AssertEqual(t, string(raw), importantString)
+}