1 files changed, 67 insertions, 0 deletions
diff --git a/third_party/rust/failure/tests/macro_trailing_comma.rs b/third_party/rust/failure/tests/macro_trailing_comma.rs
new file mode 100644
index 0000000000..012d006170
--- /dev/null
+++ b/third_party/rust/failure/tests/macro_trailing_comma.rs
@@ -0,0 +1,67 @@
+#[macro_use]
+extern crate failure;
+
+// NOTE:
+//
+// This test is in a separate file due to the fact that ensure! cannot be used
+// from within failure.
+//
+// (you get: 'macro-expanded `macro_export` macros from the current crate cannot
+//           be referred to by absolute paths')
+
+// Encloses an early-returning macro in an IIFE so that we
+// can treat it as a Result-returning function.
+macro_rules! wrap_early_return {
+    ($expr:expr) => {{
+        fn func() -> Result<(), failure::Error> {
+            let _ = $expr;
+
+            #[allow(unreachable_code)]
+            Ok(())
+        }
+        func().map_err(|e| e.to_string())
+    }};
+}
+
+#[test]
+fn bail() {
+    assert_eq!(
+        wrap_early_return!(bail!("test")),
+        wrap_early_return!(bail!("test",)));
+    assert_eq!(
+        wrap_early_return!(bail!("test {}", 4)),
+        wrap_early_return!(bail!("test {}", 4,)));
+}
+
+#[test]
+fn ensure() {
+    assert_eq!(
+        wrap_early_return!(ensure!(false, "test")),
+        wrap_early_return!(ensure!(false, "test",)));
+    assert_eq!(
+        wrap_early_return!(ensure!(false, "test {}", 4)),
+        wrap_early_return!(ensure!(false, "test {}", 4,)));
+}
+
+#[test]
+fn single_arg_ensure() {
+    assert_eq!(
+        wrap_early_return!(ensure!(false)),
+        Err("false".to_string()));
+    assert_eq!(
+        wrap_early_return!(ensure!(true == false)),
+        Err("true == false".to_string()));
+    assert_eq!(
+        wrap_early_return!(ensure!(4 == 5)),
+        Err("4 == 5".to_string()));
+}
+
+#[test]
+fn format_err() {
+    assert_eq!(
+        format_err!("test").to_string(),
+        format_err!("test",).to_string());
+    assert_eq!(
+        format_err!("test {}", 4).to_string(),
+        format_err!("test {}", 4,).to_string());
+}