More nuon tests, fix table print (#4762)

crates/nu-command/tests/format_conversions/nuon.rs

@@ -126,3 +126,39 @@ fn binary_roundtrip() {
 
     assert_eq!(actual.out, "0x[1FFF]");
 }
+
+#[test]
+fn read_binary_data() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample.nuon | get 5.3
+        "#
+    ));
+
+    assert_eq!(actual.out, "31")
+}
+
+#[test]
+fn read_record() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample.nuon | get 4.name
+        "#
+    ));
+
+    assert_eq!(actual.out, "Bobby")
+}
+
+#[test]
+fn read_bool() {
+    let actual = nu!(
+        cwd: "tests/fixtures/formats", pipeline(
+        r#"
+            open sample.nuon | get 3 | $in == $true
+        "#
+    ));
+
+    assert_eq!(actual.out, "true")
+}

crates/nu-engine/src/column.rs

@@ -11,6 +11,8 @@ pub fn get_columns(input: &[Value]) -> Vec<String> {
                     columns.push(col.to_string());
                 }
             }
+        } else {
+            return vec![];
         }
     }
 

tests/fixtures/formats/sample.nuon

@@ -0,0 +1,20 @@
+# Some sample nuon values
+[
+    # The nuon compact table format
+    [[a, nuon, table]; [1, 2, 3], [4, 5, 6]],
+
+    # A filesize
+    100kib,
+
+    # A duration
+    100sec
+
+    # A boolean
+    true,
+
+    # A record
+    {name: "Bobby", age: 99}
+
+    # Binary data
+    0x[11, ff, ee, 1f]
+]