make grid throw an error when not enough columns (#12672)

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# Description
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Resolves #12654. 

# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->

`grid` can now throw an error.

# Tests + Formatting
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Added relevant test.

crates/nu-command/src/viewers/griddle.rs

@@ -233,14 +233,17 @@ fn create_grid_output(
         }
     }
 
-    Ok(
     if let Some(grid_display) = grid.fit_into_width(cols as usize) {
-            Value::string(grid_display.to_string(), call.head)
+        Ok(Value::string(grid_display.to_string(), call.head).into_pipeline_data())
     } else {
-            Value::string(format!("Couldn't fit grid into {cols} columns!"), call.head)
+        Err(ShellError::GenericError {
+            error: format!("Couldn't fit grid into {cols} columns"),
+            msg: "too few columns to fit the grid into".into(),
+            span: Some(call.head),
+            help: Some("try rerunning with a different --width".into()),
+            inner: Vec::new(),
+        })
     }
-        .into_pipeline_data(),
-    )
 }
 
 #[allow(clippy::type_complexity)]

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

@@ -0,0 +1,8 @@
+use nu_test_support::nu;
+
+#[test]
+fn grid_errors_with_few_columns() {
+    let actual = nu!("[1 2 3 4 5] | grid --width 5");
+
+    assert!(actual.err.contains("Couldn't fit grid into 5 columns"));
+}

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

@@ -39,6 +39,7 @@ mod format;
 mod generate;
 mod get;
 mod glob;
+mod griddle;
 mod group_by;
 mod hash_;
 mod headers;