Golang: Returning array at http response in Gin framework doesn't work

I am trying to return array []Employee as a response. Is has len 2. But postman shows that responses body is empty.

type People struct {
	Height         int32          `json:"height" binding:"required"`
        Weight         int32          `json:"weight" binding:"required"`
}

type Employee struct {
	Salary int `json:"salary"`
	People
}

c.JSON(http.StatusOK, employeeArray)

I found in google that golang has some porblems with inner Binding structures.

UPD: code with MarshalJSON overriding. Here is the porblem

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

type TypeName struct {
	Name string `json:"name" binding:"required"`
}

func (p TypeName) MarshalJSON() ([]byte, error) {
	return []byte("Joe"), nil
}

type People struct {
	Height int32 `json:"height" binding:"required"`
	Weight int32 `json:"weight" binding:"required"`
	TypeName
}

type Employee struct {
	Salary int `json:"salary"`
	People
}

func main() {
	r := gin.Default()

	r.GET("/employees", func(c *gin.Context) {
		employeeArray := []Employee{
			{
				Salary: 10000,
				People: People{
					Height: 170,
					Weight: 80,
				},
			},
			{
				Salary: 20000,
				People: People{
					Height: 175,
					Weight: 80,
				},
			},
		}

		c.JSON(http.StatusOK, employeeArray)
	})
	_ = r.Run()
}

>
> func (p TypeName) MarshalJSON() ([]byte, error) {
> return []byte("Joe"), nil
> }
>

[]byte("Joe") is not a valid json. It should be quoted. If you pay attention to the log of gin, you should see an error message there: Error #01: json: error calling MarshalJSON for type main.Employee: invalid character 'J' looking for beginning of value. This one should work:

func (p TypeName) MarshalJSON() ([]byte, error) {
    return []byte(`"Joe"`), nil
}

And here is a demo for time.Time:

package main

import (
	"net/http"
	"time"

	"github.com/gin-gonic/gin"
)

type Time struct {
	StandardTime time.Time
}

func (p Time) MarshalJSON() ([]byte, error) {
	timeString := p.StandardTime.Format(time.RFC3339)
	return json.Marshal(timeString)
}

func main() {
	r := gin.Default()

	r.GET("/time", func(c *gin.Context) {
		timeArray := []Time{
			{
				StandardTime: time.Now(),
			},
			{
				StandardTime: time.Now().Add(30 * time.Minute),
			},
		}

		c.JSON(http.StatusOK, timeArray)
	})
	_ = r.Run()
}