Struct MutateTransform 

pub struct MutateTransform { /* private fields */ }

Performs structural changes to an envelope without a scripting runtime.

Operations are applied in order. Each operation targets a dotted path inside the envelope payload (e.g. payload.user.id). The root payload is implicit — paths are relative to the payload object.

Supported operations:

• add_field — insert or overwrite a field. Creates intermediate objects as needed.
• remove_field — delete a field. In strict mode the field must exist.
• rename_field — move a value from one path to another. In strict mode the source must exist.
• cast — convert a scalar value to another JSON type (string, int, float, bool, json).

Missing-field handling

on_missing controls behavior when an operation references a path that does not exist:

• strict (default) — the transform returns an error, which is handled by the configured ErrorPolicy.
• lenient — the operation is silently skipped.

Implementations

impl MutateTransform

pub fn new( id: impl Into<String>, operations: Vec<Operation>, on_missing: MissingMode, ) -> Self

Trait Implementations

impl MapOne for MutateTransform

fn id(&self) -> &str

fn map<'life0, 'async_trait>( &'life0 self, env: Envelope, ) -> Pin<Box<dyn Future<Output = Result<Option<Envelope>>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,