Added a first pass at sort-by

src/commands/sort_by.rs

@@ -0,0 +1,29 @@
+use crate::errors::ShellError;
+use crate::prelude::*;
+use derive_new::new;
+
+#[derive(new)]
+pub struct SortBy;
+
+impl crate::Command for SortBy {
+    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+        let fields: Result<Vec<_>, _> = args.args.iter().map(|a| a.as_string()).collect();
+        let fields = fields?;
+
+        let mut output = args.input.into_iter().collect::<Vec<_>>();
+
+        output.sort_by_key(|item| {
+            fields
+                .iter()
+                .map(|f| item.get_data_by_key(f).borrow().copy())
+                .collect::<Vec<Value>>()
+        });
+
+        let output = output
+            .iter()
+            .map(|o| ReturnValue::Value(o.copy()))
+            .collect();
+
+        Ok(output)
+    }
+}