How to locally test changes to a golang module

Problem

I have a golang module called fditch that I have updated. I want to test the modified module locally without needing to publish it.

Requirements

To properly test my module, I created another go module called example that uses the fditch module.

My directory structure looks like this:

.
├── fditch/
│   ├── go.mod
│   └── ...
└── example/
    ├── go.sum
    ├── go.mod
    └── main.go

In main.go, I simply make use of the module. The go.mod file looks like this:

module example.com/m

go 1.19

require (
	github.com/ShaigroRB/go-free-discount-itch v1.0.0 // indirect
	golang.org/x/net v0.7.0 // indirect
)

Solution

The “replace” keyword can be used in the go.mod file to point to a local module instead of the one on the web.

After the change, the go.mod file looks like this:

module example.com/m

go 1.19

require (
	github.com/ShaigroRB/go-free-discount-itch v1.0.0 // indirect
	golang.org/x/net v0.7.0 // indirect
)

// Here the path is relative. It works with absolute paths too.
replace github.com/ShaigroRB/go-free-discount-itch => ../fditch