Unit Test

[tiagosouza488]

I looked through all the examples in the repository but I didn't find a way to use mocks. Is something like go.mongodb.org/mongo-driver/mongo/integration/mtest possible?

`
func TestFindOne(t *testing.T) {
mt := mtest.New(t, mtest.NewOptions().ClientType(mtest.Mock))
defer mt.Close()

mt.Run("success", func(mt *mtest.T) {
	userCollection = mt.Coll
	expectedUser := user{
		ID:    primitive.NewObjectID(),
		Name:  "john",
		Email: "john.doe@test.com",
	}

	mt.AddMockResponses(mtest.CreateCursorResponse(1, "foo.bar", mtest.FirstBatch, bson.D{
		{"_id", expectedUser.ID},
		{"name", expectedUser.Name},
		{"email", expectedUser.Email},
	}))
	userResponse, err := getFromID(expectedUser.ID)
	assert.Nil(t, err)
	assert.Equal(t, &expectedUser, userResponse)
})

}
`

[mehran-prs]

Yes, I think you can use go.mongodb.org/mongo-driver/mongo/integration/mtest for mgm as well, because it uses mongo-driver library under the hood.
For example, when you call the FindByID method on an mgm collection, it uses FindOne method of the mongo-driver's Collection under the hood, so you can mock FinOne and then test it.
mgm's Collection embeds mongo-driver's Collection actually, so you can mock all of the mongo-driver methods as well.

I'm just unsure whether we need to provided the mocked mongo-driver's Collection to mgm's Collection or it let us create the mgm Collection from mocked DB instance. If it needs, we have two solutions:

• Add mgm Collection constructor that gets the mocked mongo-driver's Collection as a param.
• Update mgm Collection manually, like this:

c:=mgm.CollectionByName("test")
c.Collection=mt.Coll // assign mocked collection as a mongo-driver collection to mgm Collection