Excerpt of a testing strategy for Go http handlers.

repos::campus_repo.go

package repos

import (
	"fabric-server/models"

	"labix.org/v2/mgo"
	"labix.org/v2/mgo/bson"
)

type CampusRepo interface {
	All() models.Campuses
	AllById(...models.CampusId) models.Campuses
	Count() int
	Create(*models.Campus) models.Errors
}

func NewCampusRepo() CampusRepo {
	return newCampusRepo(session.DB(""))
}

type campusRepo struct{ c *mgo.Collection }

func newCampusRepo(db *mgo.Database) campusRepo {
	c := db.C("campuses")
	return campusRepo{c: c}
}

func (r campusRepo) All() (c models.Campuses) {
	panicIf(r.c.Find(nil).All(&c))
	return
}

func (r campusRepo) AllById(ids ...models.CampusId) (c models.Campuses) {
	panicIf(r.c.Find(m{"_id": toOids(ids)}).All(&c))
	return
}

func (r campusRepo) Count() int {
	c, e := r.c.Count()
	panicIf(e)
	return c
}

func (r campusRepo) Create(o *models.Campus) models.Errors {
	if errors := o.Errors(); errors.Present() {
		return errors
	}

	oid := bson.NewObjectId()
	o.Id = models.CampusId(oid.Hex())

	doc := toDoc(o)
	doc["_id"] = oid
	doc["cat"] = oid.Time()
	doc["uat"] = oid.Time()

	panicIf(r.c.Insert(doc))

	return noErrors
}

repos::fake_campus_repo.go

package repos

import "fabric-server/models"

// make sure FakeCampusRepo implements CampusRepo
var _ CampusRepo = (*fakeCampusRepo)(nil)

func NewFakeCampusRepo() *fakeCampusRepo {
	return &fakeCampusRepo{
		AllStub:     func() models.Campuses { panic("stub called!") },
		AllByIdStub: func(...models.CampusId) models.Campuses { panic("stub called!") },
		CountStub:   func() int { panic("stub called!") },
		CreateStub:  func(*models.Campus) models.Errors { panic("stub called!") },
	}
}

type fakeCampusRepo struct {
	AllStub     func() models.Campuses
	AllByIdStub func(...models.CampusId) models.Campuses
	CreateStub  func(*models.Campus) models.Errors
	CountStub   func() int
}

func (r fakeCampusRepo) All() models.Campuses {
	return r.AllStub()
}

func (r fakeCampusRepo) AllById(ids ...models.CampusId) models.Campuses {
	return r.AllByIdStub(ids...)
}

func (r fakeCampusRepo) Count() int {
	return r.CountStub()
}

func (r fakeCampusRepo) Create(m *models.Campus) models.Errors {
	return r.CreateStub(m)
}

web::admin::campuses::index.go

package campuses

import (
	"fabric-server/models"
	"fabric-server/models/roles"
	"fabric-server/repos"
	"fabric-server/web/sessions"
	"fabric-server/web/utils/pages"
	"fabric-server/web/utils/send"
	"net/http"
)

func Index(w http.ResponseWriter, r *http.Request) {
	indexHtml(w, r)
}

func indexHtml(w http.ResponseWriter, r *http.Request) {
	repo := newCampusRepo()
	sess := newSession(r)

	if sess.Anonymous() {
		send.ThroughAdminLogin(w, r)
		return
	}

	if !sess.HasRole(roles.SystemAdmin) {
		send.Forbidden(w)
		return
	}

	page := pages.New(`pages/admin/campuses/index`, r.Header)
	page.WritePool(indexPoolFor(sess, repo))
	send.Page(w, page)
}

func indexPoolFor(s sessions.Session, repo repos.CampusRepo) indexPool {
	return indexPool{
		FirstPerson: s.FirstPerson(),
		Campuses:    repo.All(),
	}
}

type indexPool struct {
	FirstPerson models.FirstPerson `json:"firstPerson"`
	Campuses    models.Campuses    `json:"campuses"`
}

web::admin::campuses::index_test.go

package campuses

import (
	"fabric-server/models"
	"fabric-server/models/roles"
	"fabric-server/repos"
	"fabric-server/web/sessions"
	"fabric-server/web/test_helpers"
	"fabric-server/web/utils/status"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/stretchr/testify/assert"
)

func Test_Index_SeeOther(t *testing.T) {
	defer setDefaults()

	newSession = func(*http.Request) sessions.Session {
		sess := sessions.NewFakeSession()
		sess.AnonymousStub = func() bool { return true }
		return sess
	}

	newCampusRepo = func() repos.CampusRepo {
		return repos.NewFakeCampusRepo()
	}

	w := httptest.NewRecorder()
	r := test_helpers.NewRequest("GET", "/admin/campuses")

	Index(w, r)

	assert.Equal(t, w.Code, status.SeeOther)
	assert.Equal(t, w.Header().Get("Location"), "/admin/login?rp=%2Fadmin%2Fcampuses")
}

func Test_Index_Forbidden(t *testing.T) {
	defer setDefaults()

	newSession = func(*http.Request) sessions.Session {
		sess := sessions.NewFakeSession()
		sess.AnonymousStub = func() bool { return false }
		sess.HasRoleStub = func(...roles.Role) bool { return false }
		return sess
	}

	newCampusRepo = func() repos.CampusRepo {
		return repos.NewFakeCampusRepo()
	}

	w := httptest.NewRecorder()
	r := test_helpers.NewRequest("GET", "/admin/campuses")

	Index(w, r)

	assert.Equal(t, w.Code, status.Forbidden)
}

func Test_Index_OK(t *testing.T) {
	defer setDefaults()

	newSession = func(*http.Request) sessions.Session {
		sess := sessions.NewFakeSession()
		sess.AnonymousStub = func() bool { return false }
		sess.HasRoleStub = func(...roles.Role) bool { return true }
		sess.FirstPersonStub = func() (m models.FirstPerson) { return }
		return sess
	}

	newCampusRepo = func() repos.CampusRepo {
		repo := repos.NewFakeCampusRepo()
		repo.AllStub = func() (m models.Campuses) {
			return
		}
		return repo
	}

	w := httptest.NewRecorder()
	r := test_helpers.NewRequest("GET", "/admin/campuses")

	Index(w, r)

	assert.Equal(t, w.Code, status.OK)
}

web::admin::campuses::init.go

package campuses

import (
	"fabric-server/repos"
	"fabric-server/web/sessions"
	"net/http"
)

var newCampusRepo func() repos.CampusRepo
var newSession func(*http.Request) sessions.Session

func setDefaults() {
	newCampusRepo = repos.NewCampusRepo
	newSession = sessions.New
}

func init() {
	setDefaults()
}