This commit is the continuing phase of extracting functionality to subcrates. We extract test helpers and begin to change Nu shell's test organization along with it.

tests/shell/mod.rs

@@ -0,0 +1,32 @@
+mod pipeline {
+    use test_support::fs::Stub::FileWithContent;
+    use test_support::playground::Playground;
+    use test_support::{nu_combined, pipeline};
+
+    #[test]
+    fn it_arg_works_with_many_inputs_to_external_command() {
+        Playground::setup("it_arg_works_with_many_inputs", |dirs, sandbox| {
+            sandbox.with_files(vec![
+                FileWithContent("file1", "text"),
+                FileWithContent("file2", " and more text"),
+            ]);
+
+            let (stdout, stderr) = nu_combined!(
+                cwd: dirs.test(), pipeline(
+                r#"
+                    echo hello world
+                    | split-row " "
+                    | ^echo $it
+                "#
+            ));
+
+            #[cfg(windows)]
+            assert_eq!("hello world", stdout);
+
+            #[cfg(not(windows))]
+            assert_eq!("helloworld", stdout);
+
+            assert!(!stderr.contains("No such file or directory"));
+        })
+    }
+}