From 508d74fe4afe30ddff2af2f95845f10910ae57f1 Mon Sep 17 00:00:00 2001
From: Devel <Denislav08@proton.me>
Date: Tue, 2 Jun 2026 18:37:35 +0300
Subject: [PATCH] Show usage when invoked without argments

* exit with code 1 when no arguments
* add a test for no arguments.
* Update test_sed.rs
* cargo fmt
* pass -n for missing script arguments test

Issue: #274
PR: #409
---
 src/sed/mod.rs            | 9 +++++++++
 tests/by-util/test_sed.rs | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/sed/mod.rs b/src/sed/mod.rs
index 1206140..7605f52 100644
--- a/src/sed/mod.rs
+++ b/src/sed/mod.rs
@@ -36,6 +36,15 @@ const USAGE: &str = "sed [OPTION]... [script] [file]...";
 #[uucore::main]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let matches = uu_app().try_get_matches_from(args)?;
+
+    // Don't use arg_required_else_help when declaring command
+    // as it exits with code 2 and we use it to check
+    // default matches in tests.
+    if !matches.args_present() {
+        let _ = uu_app().print_help();
+        std::process::exit(1);
+    }
+
     let (scripts, files) = get_scripts_files(&matches)?;
     let mut context = build_context(&matches);
 
diff --git a/tests/by-util/test_sed.rs b/tests/by-util/test_sed.rs
index fdc13bd..401e887 100644
--- a/tests/by-util/test_sed.rs
+++ b/tests/by-util/test_sed.rs
@@ -54,11 +54,20 @@ fn test_silent_alias() {
 #[test]
 fn test_missing_script_argument() {
     new_ucmd!()
+        .args(&["-n"])
         .fails()
         .code_is(1)
         .stderr_contains("missing script");
 }
 
+#[test]
+fn test_no_arguments() {
+    new_ucmd!()
+        .fails()
+        .code_is(1)
+        .stdout_contains("Stream editor for filtering and transforming text");
+}
+
 #[test]
 fn test_positional_script_ok() {
     new_ucmd!().arg("l").succeeds().code_is(0);