Command tests (#922)

* WIP command tests

* Finish marking todo tests

* update

* update

* Windows cd test ignoring

crates/nu-command/tests/main.rs

@@ -0,0 +1,26 @@
+use nu_command::create_default_context;
+use nu_protocol::engine::StateWorkingSet;
+use quickcheck_macros::quickcheck;
+
+mod commands;
+mod format_conversions;
+
+// use nu_engine::EvaluationContext;
+
+#[quickcheck]
+fn quickcheck_parse(data: String) -> bool {
+    let (tokens, err) = nu_parser::lex(data.as_bytes(), 0, b"", b"", true);
+    let (lite_block, err2) = nu_parser::lite_parse(&tokens);
+
+    if err.is_none() && err2.is_none() {
+        let cwd = std::env::current_dir().expect("Could not get current working directory.");
+        let context = create_default_context(cwd);
+        {
+            let mut working_set = StateWorkingSet::new(&context);
+            working_set.add_file("quickcheck".into(), data.as_bytes());
+
+            let _ = nu_parser::parse_block(&mut working_set, &lite_block, false);
+        }
+    }
+    true
+}