Expand git alias

commands/runner.go

@@ -1,6 +1,7 @@
 package commands
 
 import (
+	"fmt"
 	"github.com/jingweno/gh/git"
 	"os"
 )
@@ -15,6 +16,8 @@ func (r *Runner) Execute() error {
 		usage()
 	}
 
+	expandAlias(args)
+
 	for _, cmd := range All() {
 		if cmd.Name() == args.First() && cmd.Runnable() {
 			cmdArgs := args.Rest()
@@ -54,3 +57,12 @@ func (r *Runner) Execute() error {
 
 	return git.SysExec(args.First(), args.Rest()...)
 }
+
+func expandAlias(args *Args) {
+	cmd := args.First()
+	expandedCmd, err := git.Config(fmt.Sprintf("alias.%s", cmd))
+	if err == nil && expandedCmd != "" {
+		args.Remove(0)
+		args.Prepend(expandedCmd)
+	}
+}

git/git.go

@@ -107,6 +107,15 @@ func Log(sha1, sha2 string) (string, error) {
 	return outputs, nil
 }
 
+func Config(name string) (string, error) {
+	output, err := execGitCmd("config", name)
+	if err != nil {
+		return "", fmt.Errorf("Unknown config %s", name)
+	}
+
+	return output[0], nil
+}
+
 func SysExec(command string, args ...string) error {
 	cmd := cmd.New("git")
 	cmd.WithArg(command)