The best way I have found to test Gin Endpoints in GO-Lang, end to end, I'n a simple and easy to maintain way. I'm doing this pattern + dependency injection + the repository design pattern with data driven and seeded tests on every build.

main_test.go

package main

import (
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

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

func TestGetHttpRegisterFlowPagesLoadFull(t *testing.T) {
	var tests = []struct {
		url         string
		mustContain string
	}{
		{"/v0/register", "🎃"},
		{"/v0/verify", "The token from your email."},
		{"/v0/login", "🌎"},
	}

	engine := GetGin(false)

	for _, tt := range tests {
		testname := fmt.Sprintf("%s=>%s", tt.url, tt.mustContain)

		t.Run(
			testname,
			func(t *testing.T) {
				DoGetWebTest(t, engine, tt.url, tt.mustContain)
			},
		)
	}
}

func DoGetWebTest(t *testing.T, engine *gin.Engine, url string, mustContain string) {

	req, _ := http.NewRequest("GET", url, nil)

	testHTTPResponse(t, engine, req, func(w *httptest.ResponseRecorder) bool {
		statusOK := w.Code == http.StatusOK

		p, err := io.ReadAll(w.Body)

		pageOK := err == nil && strings.Index(string(p), mustContain) > 0

		return statusOK && pageOK
	})
}

func testHTTPResponse(t *testing.T, r *gin.Engine, req *http.Request, f func(w *httptest.ResponseRecorder) bool) {

	w := httptest.NewRecorder()

	r.ServeHTTP(w, req)

	if !f(w) {
		t.Fail()
	}
}