Add a run package responsible for running git commands

- Add better git error handling
- Move repo helpers into a separate package

pkg/test/helpers.go

@@ -0,0 +1,73 @@
+package test
+
+import (
+	"fmt"
+	"git-get/pkg/io"
+	"git-get/pkg/run"
+	"path"
+	"testing"
+)
+
+func (r *Repo) writeFile(filename string, content string) {
+	path := path.Join(r.path, filename)
+	err := io.Write(path, content)
+	checkFatal(r.t, err)
+}
+
+func (r *Repo) init() {
+	err := run.Git("init", "--quiet", r.path).AndShutUp()
+	checkFatal(r.t, err)
+}
+
+func (r *Repo) stageFile(path string) {
+	err := run.Git("add", path).OnRepo(r.path).AndShutUp()
+	checkFatal(r.t, err)
+}
+
+func (r *Repo) commit(msg string) {
+	err := run.Git("commit", "-m", fmt.Sprintf("%q", msg), "--author=\"user <user@example.com>\"").OnRepo(r.path).AndShutUp()
+	checkFatal(r.t, err)
+}
+
+func (r *Repo) branch(name string) {
+	err := run.Git("branch", name).OnRepo(r.path).AndShutUp()
+	checkFatal(r.t, err)
+}
+
+func (r *Repo) tag(name string) {
+	err := run.Git("tag", "-a", name, "-m", name).OnRepo(r.path).AndShutUp()
+	checkFatal(r.t, err)
+}
+
+func (r *Repo) checkout(name string) {
+	err := run.Git("checkout", name).OnRepo(r.path).AndShutUp()
+	checkFatal(r.t, err)
+}
+
+func (r *Repo) clone() *Repo {
+	dir, err := io.TempDir()
+	checkFatal(r.t, err)
+
+	url := fmt.Sprintf("file://%s/.git", r.path)
+	err = run.Git("clone", url, dir).AndShutUp()
+	checkFatal(r.t, err)
+
+	clone := &Repo{
+		path: dir,
+		t:    r.t,
+	}
+
+	clone.t.Cleanup(r.cleanup)
+	return clone
+}
+
+func (r *Repo) fetch() {
+	err := run.Git("fetch", "--all").OnRepo(r.path).AndShutUp()
+	checkFatal(r.t, err)
+}
+
+func checkFatal(t *testing.T, err error) {
+	if err != nil {
+		t.Fatalf("failed making test repo: %+v", err)
+	}
+}