OLX talk - #3 Introduction to Golang Interfaces and Dependency Inversion Principle

Code examples are inside cmd folder.

Run go mod vendor to install dependencies.

Unit test for the examples cmd/06-test-gomock and cmd/07-test-aws-dynamo are using gomock, read the docs to know how to install. Commands to generate the gomock files for the code examples:

mockgen -source=cmd/06-test-gomock/repo_database.go -destination=repo_mock.go -package=main

mockgen -source=./vendor/github.com/aws/aws-sdk-go/service/dynamodb/dynamodbiface/interface.go -destination=dynamodb_mock.go -package=main

You need to move the generated go mock files to the correct folder, alternatively you can also change the -destination flag to the correct folder

Examples:

• cmd/01-no-interface: code with a database repository without interface

  • run: go run cmd/01-no-interface/*.go

• cmd/02-interface: code with a database repository with interface

  • run: go run cmd/02-interface/*.go

• cmd/03-database-map: code with a database repository and map repository

  • run: go run cmd/03-database-map/*.go

• cmd/04-test-database/: code with an handler endpoint that uses the database repository, creates a server on port 8080. It has unit tests for the handler using the database repository.

  • run: go run cmd/04-test-database/main.go cmd/04-test-database/repo_database.go
  • http request example: 127.0.0.1:8080/person?name=joe
  • run unit test: go test ./cmd/04-test-database/

• cmd/05-test-map: handler unit test with the map repository

  • run unit test: go test ./cmd/05-test-map

• cmd/06-test-gomock: handler unit test using gomock

  • run unit test: go test ./cmd/05-test-map

• cmd/07-test-aws-dynamo: handler now uses an aws dynamo table, using gomock for unit testing

  • run unit test: go test ./cmd/07-test-aws-dynamo