git-sugpatch: Print error and exit on `Config::get` error

Add `exitcode` to exit with an appropriate code.

Add the `gseprintln` macro to wrap `eprintln!()`, prefixing the output
with "error: ".

2 files changed, 19 insertions, 1 deletions

diff --git a/src/bin/git-sugpatch.rs b/src/bin/git-sugpatch.rs
index 04b687d..0159307 100644
--- a/src/bin/git-sugpatch.rs
+++ b/src/bin/git-sugpatch.rs
@@ -1,7 +1,10 @@
 use std::env;
 use std::process;
 
+use exitcode;
+
 use github_suggestion::{Client, Suggestion, SuggestionUrl};
+use github_suggestion_cli::gseprintln;
 use github_suggestion_cli::config::Config;
 use github_suggestion_cli::error::Error;
 use github_suggestion_cli::is_suggestion_id;
@@ -10,7 +13,14 @@ use github_suggestion_cli::is_suggestion_id;
 fn main() {
     let args: Vec<_> = env::args().collect();
 
-    let config = Config::get(&args).unwrap();
+    let config = match Config::get(&args) {
+        Ok(c) => c,
+        Err(e) => {
+            gseprintln!(e);
+
+            process::exit(exitcode::DATAERR);
+        },
+    };
 
     if config.suggestions.is_empty() {
         process::exit(111);
diff --git a/src/error.rs b/src/error.rs
index c857bd2..bcca3e1 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -7,3 +7,11 @@ pub enum Error {
     #[error("Unable to parse regex")]
     Regex(#[from] regex::Error),
 }
+
+
+#[macro_export]
+macro_rules! gseprintln {
+    ($arg:expr) => ({
+        eprintln!("error: {}", $arg);
+    })
+}