Struct OperatorTestHarness 

pub struct OperatorTestHarness<T: FFIOperator> { /* private fields */ }

Test harness for FFI operators

This harness provides a complete testing environment for FFI operators with:

• Mock FFI context with test-specific callbacks
• State management via TestContext
• Version tracking
• Log capture (to stderr for now)
• Full support for apply() and get_rows()

Implementations

impl<T: FFIOperator> OperatorTestHarness<T>

pub fn builder() -> TestHarnessBuilder<T>

Create a new test harness builder

pub fn apply(&mut self, input: FlowChange) -> Result<FlowChange>

Apply a flow change to the operator

pub fn get_rows( &mut self, row_numbers: &[RowNumber], ) -> Result<Vec<Option<Row>>>

Get rows by their row numbers

pub fn version(&self) -> CommitVersion

Get the current version

pub fn set_version(&mut self, version: CommitVersion)

Set the current version

pub fn state(&self) -> TestStateStore

Get access to the state store for assertions

pub fn assert_state<K>(&self, key: K, expected: Value)

where K: EncodableKey,

Assert that a state key exists with the given value

pub fn logs(&self) -> Vec<String>

Get captured log messages

pub fn clear_logs(&self)

Clear captured log messages

pub fn snapshot_state(&self) -> HashMap<EncodedKey, EncodedValues>

Take a snapshot of the current state

pub fn restore_state(&mut self, snapshot: HashMap<EncodedKey, EncodedValues>)

Restore state from a snapshot

pub fn reset(&mut self) -> Result<()>

Reset the harness to initial state

pub fn create_operator_context(&mut self) -> OperatorContext

Create an operator context for direct access

This is useful for testing components that need an OperatorContext without going through the apply() or get_rows() methods.

Example

let mut harness = TestHarnessBuilder::<MyOperator>::new().build()?;
let mut ctx = harness.create_operator_context();
let (row_num, is_new) = ctx.get_or_create_row_number(harness.operator(), &key)?;

pub fn operator(&self) -> &T

Get a reference to the operator

pub fn operator_mut(&mut self) -> &mut T

Get a mutable reference to the operator

pub fn node_id(&self) -> FlowNodeId

Get the node ID