Add tests

src/parser/shell_expand/mod.rs

@@ -679,4 +679,15 @@ mod test {
         let expected = array!["3"];
         assert_eq!(expected, expand_string(line, &functions!(), false));
     }
+
+    #[test]
+    fn inline_expression() {
+        let cases = vec![
+            (array!["5"], "@len([0 1 2 3 4])"),
+            (array!["FxOxO"], "$join(@chars(FOO), 'x')")
+        ];
+        for (expected, input) in cases {
+            assert_eq!(expected, expand_string(input, &functions!(), false));
+        }
+    }
 }