fix(cli): abort if no files staged

cmd/cli.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"bytes"
 	"fmt"
 	"log"
 	"os"
@@ -64,6 +65,18 @@ func mainMode(cmd *cobra.Command, args []string) {
 	cfg := config.Lookup(config.Init())
 	commitParams := getGitCommitCmd(cmd)
 	dryRun, _ := cmd.Flags().GetBool("dry-run")
+	if !dryRun {
+		buf := &bytes.Buffer{}
+		process := exec.Command("git", "diff", "--name-only", "--cached")
+		process.Stdout = buf
+		err := process.Run()
+		if err != nil {
+			log.Fatal(err)
+		}
+		if buf.String() == "" {
+			log.Fatal("No files staged")
+		}
+	}
 
 	cc := &parser.CC{}
 	message, _ := cmd.Flags().GetString("message")

pkg/config/cfg.go

@@ -105,14 +105,19 @@ func getGitVar(var_name string) (string, error) {
 	}
 }
 
+func GetEditor() string {
+	editor := os.Getenv("EDITOR")
+	if editor != "" {
+		return editor
+	}
+	return "vi"
+}
+
 // search GIT_EDITOR, then fall back to $EDITOR
 func GetGitEditor() string {
 	editor, err := getGitVar("GIT_EDITOR") // TODO: shell-split the string
 	if err != nil {
-		editor = os.Getenv("EDITOR")
-		if editor == "" {
-			log.Fatal(fmt.Errorf("unable to look up `git var GIT_EDITOR` or `$EDITOR`"))
-		}
+		return GetEditor()
 	}
 	return editor
 }