An extensible and generic mongo repository pattern implementation

• Golang >= 1.20
• Docker (for testing only)

Pending to add

go get github.com/Drafteame/mgorepo

This package was made with the purpose of having a way to generify mongo actions using the repository pattern on a DDD environment. It's not an ORM, it's just a way to have a generic way to interact with mongo.

A repository is a struct that will be used to interact with the database, it should be created using the NewRepository generic function and can be configured to be extended with custom methods using struct embedding.

The sign of the NewRepository function is:

func NewRepository[
	M    Model,
	D    Dao,
	SF   SearchFilters,
	UF   UpdateFields,
](
	db             Driver,
	collectionName string,
	filterBuilders []func(SF) (*bson.E, error),
	updateBuilders []func(UF) (*bson.E, error),
) Repository[M, D, SF, SORD, SO, UF] {}

• M Model: Is a struct that will be used to interact with the repository, it should be created using just native go types and should contain all document fields of a collection. Fields should be public.
• D Dao: Is a struct that will be used to interact with the database, it should be created using mongo data types, should contain all document fields of a collection and be compliant with the generic interface DaoFiller[M Model]. Fields should be public. ID field of a Dao should be defined as primitive.ObjectID or *primitive.ObjectID using tag bson:"_id,omitempty".
• SF SearchFilters: Is a struct that will be used to filter the results of a search, it should be created using just pointers of native go types and each field should represent a type of filter that can be applied to the collection. Fields should be public.
• UF UpdateFields: Is a struct that will be used to update a document, it should be created using just native go types and each field should represent a possible updated fields of a document. Fields should be public.

• db Driver: Is an interface that implements 2 methods:
  • Client() *mongo.Client: Should return a mongo client that will be used to interact with the database (package used to interact with mongo is go.mongodb.org/mongo-driver/mongo).
  • DbName() string: Should return a string with the name of the database that will be used on the operations.
• collectionName string: Is a string with the name of the collection that will be used by the repository.
• filterBuilders []func(SF) (*bson.E, error): Is a slice of functions that will be used to build the filters that will be applied to the search. Each function should receive a SF struct and return a *bson.E with the filter that will be applied to the search. If an error is returned, the operation will be aborted. Each function should build a filter based in just one field of the SF struct, making as result that the slice of functions should have the same length as the number of fields of the SF struct.
• updateBuilders []func(UF) (*bson.E, error): Is a slice of functions that will be used to build the updates that will be applied to the document. Each function should receive a UF struct and return a *bson.E with the update that will be applied to the document. If an error is returned, the operation will be aborted. Each function should build an update based in just one field of the UF struct, making as result that the slice of functions should have the same length as the number of fields of the UF struct.