add unspanned flag to error make, add tests (#6017)

* add `unspanned` flag to error make, add tests

* fmt

crates/nu-command/tests/commands/error_make.rs

@@ -0,0 +1,26 @@
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn error_label_works() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+        error make {msg:foo label:{text:unseen}}
+        "#
+    ));
+
+    assert!(actual.err.contains("unseen"));
+    assert!(actual.err.contains("╰──"));
+}
+
+#[test]
+fn no_span_if_unspanned() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"
+        error make -u {msg:foo label:{text:unseen}}
+        "#
+    ));
+
+    assert!(!actual.err.contains("unseen"));
+}

crates/nu-command/tests/commands/mod.rs

@@ -15,6 +15,7 @@ mod each;
 mod echo;
 mod empty;
 mod enter;
+mod error_make;
 mod every;
 mod find;
 mod first;