Function remove_nested_value 

pub fn remove_nested_value(
    data: &mut OwnedDataValue,
    path: &str,
) -> Option<OwnedDataValue>

Remove the value at path and return it; None if the path does not resolve.

Completes the module’s read/write pair with a removal. Note that set_nested_value(path, OwnedDataValue::Null) is not removal — it leaves an explicit null in the tree, which survives every serialization boundary because Message’s Serialize emits context whole.

Path syntax is identical to get_nested_value and set_nested_value: dot-separated segments, numeric segments index arrays, and one leading # is stripped from an object-key segment ("data.#20" is the object key "20").

• Object keys are removed from the pair vec; the relative order of the surviving pairs is preserved.
• Array elements are removed with a tail shift, so later indices move down.
• Returns None — leaving data untouched — for a missing key, an out-of-bounds or non-numeric array index, an attempt to descend through a non-container, or an empty path. Never panics.

Note the deliberate asymmetry with the read side: get_nested_value(d, "") returns the whole tree, but there is no such thing as removing the root, so an empty path yields None rather than taking data apart.

use dataflow_rs::datavalue::OwnedDataValue;
use dataflow_rs::engine::utils::remove_nested_value;
use serde_json::json;

let mut ctx = OwnedDataValue::from(&json!({"data": {"order_id": 7, "_scratch": 42}}));

let taken = remove_nested_value(&mut ctx, "data._scratch");

assert_eq!(taken, Some(OwnedDataValue::from(&json!(42))));
assert_eq!(
    serde_json::Value::from(&ctx),
    json!({"data": {"order_id": 7}}),
);