go-git

go-git

Git repository facts for Go, behind an injected runner so callers stay testable without shelling out to the real git binary.

The facts package reads the few facts tools commonly need — the current branch, the origin remote URL, and the repository owner — and offers a forward-only check (HEAD is on a branch tip, not detached). Every operation goes through a small Runner interface; ExecRunner is the real-git implementation, and tests inject a fake.

Install

go get github.com/gomatic/go-git/facts

Requires Go 1.26+.

Usage

package main

import (
	"fmt"

	"github.com/gomatic/go-git/facts"
)

func main() {
	r := facts.NewExecRunner()

	branch, err := facts.Branch(r) // ErrDetachedHead when HEAD is detached
	if err != nil {
		panic(err)
	}

	owner, err := facts.OwnerOf(r) // upstream remote, falling back to origin
	if err != nil {
		panic(err)
	}

	fmt.Printf("on %s, owned by %s\n", branch, owner)
}

Branch, Origin, OwnerOf, and EnsureForwardOnly each take a Runner, so a caller can drive them against a fake in tests:

type fakeRunner struct {
	fn func(args ...facts.Arg) (facts.CommandOutput, error)
}

func (f fakeRunner) Run(args ...facts.Arg) (facts.CommandOutput, error) { return f.fn(args...) }

Errors are gomatic/go-error sentinels (facts.ErrDetachedHead, facts.ErrNoOrigin), matchable with errors.Is.