Add git as command and tests

git-as/main.go

@@ -0,0 +1,153 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+
+	"github.com/git-duet/git-duet"
+	"github.com/pborman/getopt"
+)
+
+var (
+	// VersionString is the git tag this binary is associated with
+	VersionString string
+	// RevisionString is the git rev this binary is associated with
+	RevisionString string
+)
+
+func main() {
+	var (
+		quiet   = getopt.BoolLong("quiet", 'q', "Silence output")
+		global  = getopt.BoolLong("global", 'g', "Change global config")
+		help    = getopt.BoolLong("help", 'h', "Help")
+		version = getopt.BoolLong("version", 'v', "Version")
+		show    = getopt.BoolLong("show", 's', "Show")
+	)
+
+	getopt.Parse()
+
+	if *help {
+		getopt.Usage()
+		os.Exit(0)
+	}
+
+	if *version {
+		fmt.Printf("%s (%s)\n", VersionString, RevisionString)
+		os.Exit(0)
+	}
+
+	configuration, err := duet.NewConfiguration()
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	gitConfig := &duet.GitConfig{Namespace: configuration.Namespace, SetUserConfig: configuration.SetGitUserConfig}
+	if *global || configuration.Global {
+		gitConfig.Scope = duet.Global
+	}
+
+	if getopt.NArgs() == 0 || *show {
+		author, err := gitConfig.GetAuthor()
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+		committers, err := gitConfig.GetCommitters()
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		printAuthor(author)
+		printNextCommitter(committers)
+		if configuration.CoAuthoredBy {
+			installHook("prepare-commit-msg")
+			// SetAuthor is needed in case neither GIT_DUET_CO_AUTHORED_BY nor GIT_DUET_SET_GIT_USER_CONFIG was set previously
+			if err = gitConfig.SetAuthor(author); err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+			if configuration.RotateAuthor {
+				installHook("post-commit")
+			}
+		}
+		os.Exit(0)
+	}
+
+	pairs, err := duet.NewPairsFromFile(configuration.PairsFile, configuration.EmailLookup)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(0)
+	}
+
+	author, err := pairs.ByInitials(getopt.Arg(0))
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(86)
+	}
+	if err = gitConfig.SetAuthor(author); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	var committers []*duet.Pair
+
+	for _, initials := range getopt.Args()[1:] {
+		committer, err := pairs.ByInitials(initials)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(86)
+		}
+
+		committers = append(committers, committer)
+	}
+
+	if err = gitConfig.SetCommitters(committers...); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	if !*quiet {
+		printAuthor(author)
+		printNextCommitter(committers)
+	}
+
+	if configuration.CoAuthoredBy {
+		installHook("prepare-commit-msg")
+		if configuration.RotateAuthor {
+			installHook("post-commit")
+		}
+	}
+}
+
+func printAuthor(author *duet.Pair) {
+	if author == nil {
+		return
+	}
+
+	fmt.Printf("GIT_AUTHOR_NAME='%s'\n", author.Name)
+	fmt.Printf("GIT_AUTHOR_EMAIL='%s'\n", author.Email)
+}
+
+func printNextCommitter(committers []*duet.Pair) {
+	if committers == nil || len(committers) == 0 {
+		return
+	}
+
+	fmt.Printf("GIT_COMMITTER_NAME='%s'\n", committers[0].Name)
+	fmt.Printf("GIT_COMMITTER_EMAIL='%s'\n", committers[0].Email)
+}
+
+func installHook(hookType string) {
+	cmd := exec.Command("git-duet-install-hook", hookType)
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+
+	err := cmd.Run()
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}