Add (near) automatic testing for command examples (#1777)

crates/nu-cli/src/commands/range.rs

@@ -58,3 +58,15 @@ fn range(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream,
 
     Ok(stream.to_output_stream())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::Range;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(Range {})
+    }
+}