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Wrapper with mocks for MongoDB and BoltDB

Package shows how to mock MongoDB or BoltDB using a single Go interface.
It's not cover all db methods from the globalsign/mgo driver's package.
Feel free to extend the package according to your needs.

Package inspired by this article - Mocking Mongo in Go

Table of contents

• How to install
• Package contents
• Interface methods being in use by realization
• MongoDB examples
• BoltDB examples
• Mocking

How to install

go get github.com/zaffka/mongodb-boltdb-mock

Package contents

• Wrapper itself (db/db.go) with:

  • db.Handler - main interface for opening, closing and controling connection to DB
  • db.Querier - interface for selecting data from DB
  • db.Refiner - interface for refining query object obtained by the Find() method

• Realization for the MongoDB (db/mgo.go)

• Realization for the BoltDB (db/bolt.go)

• A set of mocks (db/mock.go)

• Unit tests (db/db_test.go)

Interface methods being in use by realization

Interface/Function	MongoDB	Mocks	BoltDB
db.New()	+	+	+
db.Handler
Connect	+	+	+
Copy	+	+	-
CopyWithSettings	+	+	-
Close	+	+	+
ExecOn	+	+	+
db.Querier
Insert	+	+	+
Remove	+	+	+
RemoveAll	+	+	-
Update	+	+	-
UpdateAll	+	+	-
Upsert	+	+	-
Find	+	+	+
db.Refiner
One	+	+	+
All	+	+	-
Distinct	+	+	-
Count	+	+	-

MongoDB examples

...up the db

mongo := db.New(&db.Mongo{})
err := mongo.Connect("mongo://localhost:/27017")
defer mongo.Close()

...inserting data

func main() {
mongo := db.New(&db.Mongo{})
err := mongo.Connect("mongo://localhost:/27017")
defer mongo.Close()

os := new(OurStuct)
os.Save(mongo)
}

type OurStruct struct {}
func (o *OurStruct) Save(db db.Handler, databaseName, collectionName string) error {
    sess := db.Copy() //Pay attention globalsign's driver whant us to use
	defer sess.Close() //copied or clonned session of the *mgo.Session object

	err := sess.ExecOn(databaseName, collectionName).Insert(o)
	if err != nil {
		return err
	}

	return nil
}

...reading

func main() {
mongo := db.New(&db.Mongo{})
err := mongo.Connect("mongo://localhost:/27017")
defer mongo.Close()

os := new(OurStuct)
os.Save(mongo)
}

type OurStruct struct {
    ID bson.ObjectID `bson:"_id"`
}
func (o *OurStruct) Read(db db.Handler, databaseName, collectionName string) error {
	sess := db.Copy()
	defer sess.Close()

	err := sess.ExecOn(databaseName, collectionName).Find(o.ID).One(o)
	if err != nil {
		return err
	}

	return nil
}

...updating

func main() {
mongo := db.New(&db.Mongo{})
err := mongo.Connect("mongo://localhost:/27017")
defer mongo.Close()

os := new(OurStuct)
os.Save(mongo)
}

type OurStruct struct {
    ID bson.ObjectID `bson:"_id"`
}
func (o *OurStruct) Update(db db.Handler, databaseName, collectionName, update string) error {
	sess := db.Copy()
	defer sess.Close()

	_, err := sess.ExecOn(databaseName, collectionName).Upsert(bson.M{"_id": o.ID}, bson.M{"$set": bson.M{"somefield": update}})
	if err != nil {
		return err
	}

	return nil
}

and so on...

BoltDB examples

Features:

• Database opens at the system's temp directory (/tmp @ linux)
• Working directory with db file will look like /tmp/[basename][random numbers]/[basename]
• bolt.Close() removes the working directory and a db file
• Use boltbrowser to work with bolt's files
• Any structs and data types can be used as keys and values to store in BoltDB (Gob marshaling\unmarshaling inside)
• BoltDB uses buckets as Mongo's collections analogues

...up the db

bolt := db.New(&db.Bolt{})
err := bolt.Connect("bolt", "bucketOne", "bucketTwo")
defer bolt.Close()

Where "bolt" - it's a [basename] and others are variadic set of buckets names.
If the list scipped bucket with the default name being in use.

...inserting data

bolt := db.New(&db.Bolt{})
err := bolt.Connect("bolt", "bucketOne", "bucketTwo")
defer bolt.Close()

err = bolt.ExecOn("bucketOne").Insert("key", &db.Mock{Msg: "test"})
if err != nil {
	log.Error(err)
}

...reading

...
var res db.Mock
err := bolt.ExecOn("bucketOne").Find("key").One(&res)
...

...deleting

...
err := bolt.ExecOn("bucketOne").Remove("key")
...

Mocking

Just replace &db.Mongo{} (or &db.Bolt{}) with &db.Mock{} and cover your functions by unit tests with ease.
No real database needed.

func main() {
mongo := db.New(&db.Mongo{})
mongo.ExecOn(...).Find(...)...
...

replace with

func main() {
mock := db.New(&db.Mock{})
mongo.ExecOn(...).Find(...)...
...