From 6f712bcfc5fef9c9054d010415dcd23ccb09ed7b Mon Sep 17 00:00:00 2001
From: Carter Green <carter@databento.com>
Date: Mon, 30 Dec 2024 09:40:27 -0600
Subject: [PATCH] FIX: Require at least one file for dbn CLI

---
 rust/dbn-cli/src/lib.rs                 |  1 +
 rust/dbn-cli/tests/integration_tests.rs | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/rust/dbn-cli/src/lib.rs b/rust/dbn-cli/src/lib.rs
index 5259198..a7c4dad 100644
--- a/rust/dbn-cli/src/lib.rs
+++ b/rust/dbn-cli/src/lib.rs
@@ -37,6 +37,7 @@ pub struct Args {
         value_name = "FILE...",
         value_delimiter = ' ',
         num_args = 1..,
+        required = true,
     )]
     pub input: Vec<PathBuf>,
     #[clap(
diff --git a/rust/dbn-cli/tests/integration_tests.rs b/rust/dbn-cli/tests/integration_tests.rs
index f239afa..cba5c59 100644
--- a/rust/dbn-cli/tests/integration_tests.rs
+++ b/rust/dbn-cli/tests/integration_tests.rs
@@ -790,7 +790,16 @@ fn help() {
         .arg("--help")
         .assert()
         .success()
-        .stdout(contains("Usage:"));
+        .stdout(contains("Usage:"))
+        .stderr(is_empty());
+}
+
+#[test]
+fn empty() {
+    cmd().assert().failure().stdout(is_empty()).stderr(
+        contains("the following required arguments were not provided:\n  <FILE...>")
+            .and(contains("Usage:")),
+    );
 }
 
 #[test]
@@ -799,5 +808,6 @@ fn version() {
         .arg("--version")
         .assert()
         .success()
-        .stdout(contains(env!("CARGO_PKG_VERSION")));
+        .stdout(contains(env!("CARGO_PKG_VERSION")))
+        .stderr(is_empty());
 }