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Class: PayloadWalkerWithDeduplication\<T\>

Gala Launchpad SDK 9.0.0-rc.5

Gala Launchpad SDK 9.0.0-rc.5 / index / PayloadWalkerWithDeduplication

Class: PayloadWalkerWithDeduplication<T>

Defined in: packages/launchpad-sdk/dist/utils/websocket-patterns.d.ts:158

Payload Walker with Deduplication

Recursively walks through object payloads to extract events while deduplicating by a key (e.g., transactionId, eventId). Prevents duplicate processing of the same event across multiple payload traversals.

Used to find events nested at various depths in WebSocket payloads.

Features:

  • Recursive depth limiting (prevents DoS from circular structures)
  • WeakSet tracking to prevent infinite loops on circular references
  • Configurable deduplication key
  • Callback-based event processing

Example​

// Test case: Recursive payload walking with deduplication
const walker = new PayloadWalkerWithDeduplication<{ id: string; value: number }>(
  (obj) => {
    // Extraction predicate: return event if found
    return obj.id && obj.value ? { id: obj.id, value: obj.value } : null;
  },
  (event) => event.id // Deduplication key
);

// First walk - extracts new events
const events1 = walker.walk({
  Data: { id: 'e1', value: 100 },
  nested: { id: 'e2', value: 200 }
});
console.assert(events1.length === 2);

// Second walk - skips already seen events
const events2 = walker.walk({
  Data: { id: 'e1', value: 999 }, // Already seen, skipped
  other: { id: 'e3', value: 300 }  // New, included
});
console.assert(events2.length === 1);
console.assert(events2[0].id === 'e3');

// Reset deduplication to reprocess all events
walker.reset();
const events3 = walker.walk({ Data: { id: 'e1', value: 100 } });
console.assert(events3.length === 1); // e1 is processed again

Since​

6.6.0

Type Parameters​

T​

T

Event type being extracted

Constructors​

Constructor​

new PayloadWalkerWithDeduplication<T>(extractor, dedupeKeyFn, maxDepth?): PayloadWalkerWithDeduplication<T>

Defined in: packages/launchpad-sdk/dist/utils/websocket-patterns.d.ts:163

Parameters​

extractor​

(obj) => T | null

dedupeKeyFn​

(event) => string

maxDepth?​

number

Returns​

PayloadWalkerWithDeduplication<T>

Methods​

getSeenCount()​

getSeenCount(): number

Defined in: packages/launchpad-sdk/dist/utils/websocket-patterns.d.ts:180

Get count of deduplicated events

Returns​

number

Number of unique events seen so far

reset()​

reset(): void

Defined in: packages/launchpad-sdk/dist/utils/websocket-patterns.d.ts:174

Reset deduplication state to reprocess all events

Returns​

void

walk()​

walk(payload): T[]

Defined in: packages/launchpad-sdk/dist/utils/websocket-patterns.d.ts:170

Walk through a payload and extract events

Parameters​

payload​

unknown

Root object to traverse

Returns​

T[]

Array of extracted events not previously seen