fix: improve error msg when adding coauthor with invalid key

Remove suggestion to use initials for keys since first names  might be a better option for some

README.md

@@ -46,7 +46,7 @@ $ cargo install git-mob-tool
 
 ## Configuration
 
-- Store your team members' details with keys (usually initials)
+- Store your team members' details with keys
 
   ```console
   $ git mob coauthor --add lm "Leo Messi" [email protected]

src/cli.rs

@@ -41,7 +41,7 @@ enum Commands {
     /// Add/delete/list co-author(s) from co-author repository
     ///
     /// User must store co-author(s) to co-author repository by using keys
-    /// (usually initials) before starting pair/mob programming session(s).
+    /// before starting pair/mob programming session(s).
     Coauthor(Coauthor),
 }
 

src/coauthor_repo.rs

@@ -115,9 +115,10 @@ impl CoauthorRepo for GitConfigCoauthorRepo {
             .args(["config", "--global", &full_key, coauthor])
             .output()?;
 
-        match output.status.success() {
-            true => Ok(()),
-            false => Self::git_config_error(&output),
+        match output.status.code() {
+            Some(Self::EXIT_CODE_SUCCESS) => Ok(()),
+            Some(Self::EXIT_CODE_CONFIG_INVALID_KEY) => Err(format!("Invalid key: {key}").into()),
+            _ => Self::git_config_error(&output),
         }
     }
 

tests/coauthor.rs

@@ -50,6 +50,27 @@ fn test_add_and_list_coauthors(ctx: TestContextCli) -> Result<(), Box<dyn Error>
     Ok(())
 }
 
+#[test_context(TestContextCli, skip_teardown)]
+#[test]
+fn test_add_coauthor_with_invalid_key(ctx: TestContextCli) -> Result<(), Box<dyn Error>> {
+    ctx.git()
+        .args([
+            "mob",
+            "coauthor",
+            "--add",
+            "invalid_key_with_underscore",
+            "Leo Messi",
+            "[email protected]",
+        ])
+        .assert()
+        .failure()
+        .stderr(predicate::str::diff(
+            "Error: \"Invalid key: invalid_key_with_underscore\"\n",
+        ));
+
+    Ok(())
+}
+
 #[test_context(TestContextCli, skip_teardown)]
 #[test]
 fn test_list_coauthors_given_no_coauthors_added(ctx: TestContextCli) -> Result<(), Box<dyn Error>> {

tests/help.rs

@@ -101,7 +101,7 @@ fn test_coauthor_help(ctx: TestContextCli) -> Result<(), Box<dyn Error>> {
         .stdout(predicate::str::diff(
 r#"Add/delete/list co-author(s) from co-author repository
 
-User must store co-author(s) to co-author repository by using keys (usually initials) before starting pair/mob programming session(s).
+User must store co-author(s) to co-author repository by using keys before starting pair/mob programming session(s).
 
 Usage: git mob coauthor [OPTIONS]