Struct TestSink 

pub struct TestSink { /* private fields */ }

A sink that records everything written, optionally deduplicating by a key field (upsert), optionally advertising the atomic-watermark idempotent path.

Modes:

• TestSink::new — append-only, non-idempotent.
• TestSink::keyed — dedups by key on write_batch (keyed-upsert / dedups_by_key), advertises Upsert/Delete.
• TestSink::idempotent — additionally advertises supports_idempotent_writes and stores a per-scope commit token, so the atomic-watermark path can be exercised.

Implementations

impl TestSink

pub fn new() -> Self

An append-only recording sink.

pub fn keyed(key_field: impl Into<String>) -> Self

An upsert sink that dedups by key_field in write_batch.

pub fn idempotent(key_field: impl Into<String>) -> Self

An upsert sink that also commits an atomic watermark token per scope, so it advertises (and honours) supports_idempotent_writes.

pub fn len(&self) -> usize

Number of distinct rows currently stored (keyed) or appended.

pub fn is_empty(&self) -> bool

Whether the sink holds no rows.

pub fn total_written(&self) -> usize

Total number of records passed to write_batch across all calls (counts re-delivered duplicates).

Trait Implementations

impl Clone for TestSink

fn clone(&self) -> TestSink

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for TestSink

fn default() -> TestSink

Returns the “default value” for a type.

impl Sink for TestSink

fn write_batch<'life0, 'life1, 'async_trait>( &'life0 self, records: &'life1 [Value], ) -> Pin<Box<dyn Future<Output = Result<usize, FaucetError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

Write a batch of records to the destination.

fn supports_idempotent_writes(&self) -> bool

Whether this sink can durably commit a page’s rows and a commit token in a single atomic transaction. Default: false (at-least-once only).

fn dedups_by_key(&self) -> bool

Whether this sink instance is configured to dedup by key — i.e. write_mode: upsert (or delete) with a non-empty key, so re-applying a record with the same key converges instead of duplicating. Default: false.

fn supported_write_modes(&self) -> &'static [WriteMode]

Write modes this sink can apply. Default: append-only. Sinks that implement key-based merge override this to include WriteMode::Upsert / WriteMode::Delete. The CLI rejects a configured mode that is not in this set at config-load time.

fn write_batch_idempotent<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, records: &'life1 [Value], scope: &'life2 str, token: &'life3 str, ) -> Pin<Box<dyn Future<Output = Result<usize, FaucetError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait,

Write records AND durably record token for scope, atomically.

fn last_committed_token<'life0, 'life1, 'async_trait>( &'life0 self, scope: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<Option<String>, FaucetError>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

The last token durably committed for scope, or None if this sink has never committed under that scope. Default: None.

fn connector_name(&self) -> &'static str

Stable identifier used as the connector label on metrics and the connector attribute on spans. See Source::connector_name.

fn flush<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<(), FaucetError>> + Send + 'async_trait>>

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

Flush any buffered data to the destination.

fn write_batch_partial<'life0, 'life1, 'async_trait>( &'life0 self, records: &'life1 [Value], ) -> Pin<Box<dyn Future<Output = Result<Vec<Result<(), FaucetError>>, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Write a batch and report per-row outcomes.

fn sink_guarantee(&self) -> SinkGuarantee

The strongest delivery guarantee this sink can uphold — see SinkGuarantee.

fn current_schema<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Option<Value>, FaucetError>> + Send + 'async_trait>>

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

The sink’s live destination schema as an infer_schema-shaped object ({"type":"object","properties":{ <col>: <type-fragment>, … }}), or None for a schemaless sink or a target that does not exist yet.

fn supports_schema_evolution(&self) -> bool

Whether this sink can apply additive/widening DDL via evolve_schema. Default: false. The CLI rejects on_drift: evolve against a sink that returns false at config-load.

fn evolve_schema<'life0, 'life1, 'async_trait>( &'life0 self, evolution: &'life1 SchemaEvolution, ) -> Pin<Box<dyn Future<Output = Result<(), FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Apply an additive schema evolution (new columns, lossless widenings, nullability relaxations) to the destination. MUST be idempotent (ADD COLUMN IF NOT EXISTS semantics) so concurrent runs converge.

fn config_schema(&self) -> Value

Return a JSON Schema describing the configuration this sink accepts.

fn dataset_uri(&self) -> String

Logical dataset identity for lineage emission, following OpenLineage naming conventions (https://openlineage.io/docs/spec/naming).

fn check<'life0, 'life1, 'async_trait>( &'life0 self, _ctx: &'life1 CheckContext, ) -> Pin<Box<dyn Future<Output = Result<CheckReport, FaucetError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, Self: 'async_trait,

Run a fast, non-mutating preflight probe (used by faucet doctor).