How to use main function inside test function when unit testing Gin - unit-testing

Question

I want to unit test gin controller function.
package controllers
import (
"fmt"
"net/http/httptest"
"testing"
"github.com/gin-gonic/gin"
"github.com/go-playground/assert/v2"
)
func TestGetDivisions(t *testing.T) {
tt := []struct {
Name string
EnterpriseID string
Code int
}{
{Name: "Enterprise id exists", EnterpriseID: "1", Code: 200},
{Name: "Enterprise id cannot be string", EnterpriseID: "string", Code: 404},
}
w := httptest.NewRecorder()
c, _ := gin.CreateTestContext(w)
for _, tc := range tt {
c.Params = []gin.Param{
{
Key: "enterprise_id",
Value: tc.EnterpriseID,
},
}
GetDivisions(c) // Error from here
assert.Equal(t, tc.Code, w.Code, tc.Name)
}
}
Problem is, whenever I use GetDivision function inside a test file gives error like below:
--- FAIL: TestGetDivisions (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x43c7438]
Cannot find where is a problem. Can I give test context to a function as a parameter?
And here is my GetDivisions handler:
// Get divisions of an enterprise by given id. Default id = "1"
func GetDivisions(c *gin.Context) {
var divisions []models.Division
if err := config.DB.Find(&divisions).Error; err != nil {
c.JSON(http.StatusInternalServerError, err.Error())
return
}
c.JSON(http.StatusOK, gin.H{
"divisions": divisions,
})
}

Answer 1

It seems like an error occurs in config.DB.Find(&divisions), because I think invalid memory error accurs when it reads from database and writes to variable... can you show the code of config.DB.Find(). (if it is on GitHub, you can send me link)