Port and Adapter in Go with Uber FX

Case

Sending email

Folder Structure

• cmd/sender/main.go
• internal/services/sender/sender.go
• adapters/gmail/gmail.go
• adapters/hotmail/hotmail.go

Steps

Create port

File: internal/services/sender/sender.go

• IEmailPort will be interface for adapter

Create core business

File: internal/services/sender/sender.go

• IEmailService will be interface for UberFX
• EmailService will be struct of service with attribute emailPort(will be injected by UberFX)
• NewEmailService is constructor

Create adapters

File: adapters/gmail/gmail.go

• GmailAdapter will be interface for UberFX

File: adapters/hotmail/hotmail.go
** Hotmail like gmail, just replace gmail with hotmail **

Create program

File: cmd/sender/main.go

• NewEmailAdapter function will let UberFX know that IEmailPort interface will use Gmail adapter struct
• We can switch adapter to hotmail by comment out return hotmail.NewHotmailAdapter() in function NewEmailAdapter