WIP: operator collaboration MVP

See toolshed/organising#467

pkg/git/diff.go

@@ -3,6 +3,7 @@ package git
 import (
 	"fmt"
 	"os/exec"
+	"strings"
 
 	"coopcloud.tech/abra/pkg/log"
 )
@@ -10,8 +11,8 @@ import (
 // getGitDiffArgs builds the `git diff` invocation args. It removes the usage
 // of a pager and ensures that colours are specified even when Git might detect
 // otherwise.
-func getGitDiffArgs(repoPath string) []string {
-	return []string{
+func getGitDiffArgs(repoPath, fname string) []string {
+	args := []string{
 		"-C",
 		repoPath,
 		"--no-pager",
@@ -19,24 +20,29 @@ func getGitDiffArgs(repoPath string) []string {
 		"color.diff=always",
 		"diff",
 	}
+
+	if fname != "" {
+		args = append(args, fname)
+	}
+
+	return args
 }
 
 // DiffUnstaged shows a `git diff`. Due to limitations in the underlying go-git
-// library, this implementation requires the /usr/bin/git binary. It gracefully
-// skips if it cannot find the command on the system.
-func DiffUnstaged(path string) error {
+// library, this implementation requires the /usr/bin/git binary.
+func DiffUnstaged(path, fname string) (string, error) {
 	if _, err := exec.LookPath("git"); err != nil {
-		log.Warnf("unable to locate git command, cannot output diff")
-		return nil
+		return "", fmt.Errorf("missing /usr/bin/git command? cannot output diff")
 	}
 
-	gitDiffArgs := getGitDiffArgs(path)
+	gitDiffArgs := getGitDiffArgs(path, fname)
+
+	log.Debugf("running: git %s", strings.Join(gitDiffArgs, " "))
+
 	diff, err := exec.Command("git", gitDiffArgs...).Output()
 	if err != nil {
-		return nil
+		return "", err
 	}
 
-	fmt.Print(string(diff))
-
-	return nil
+	return string(diff), nil
 }