z-deduper/lib/deduper.js

This library will allow you to build a Custom Zapier deduper for your advanced polling triggers use cases in your Zapier app.

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.getDeduper = exports.Deduper = void 0;
const lodash_1 = __importDefault(require("lodash"));
const object_hash_1 = __importDefault(require("object-hash"));
const storage_1 = require("./storage");
class Deduper {
    constructor(storage) {
        this.cache = {};
        this.storage = storage;
    }
    /**
     * Initialize the deduper
     *
     * Note: Should only be called once when the zap is activated
     */
    async initialize(currentRecords) {
        const records = this.getRecords(currentRecords);
        await this.storage.save(records);
        return true;
    }
    async load() {
        this.cache = await this.storage.load();
        return true;
    }
    /**
     * Find changes
     *
     * Compares the current records with the cached record hashes to find
     * which records are new and which are updated.
     */
    findChanges(currentRecords) {
        const changes = {
            created: [],
            updated: [],
            all: [],
        };
        const timestamp = this.getTimestamp();
        for (const record of currentRecords) {
            const recordHash = this.hash(record);
            const cachedRecordHash = this.cache[record.id];
            if (cachedRecordHash) {
                if (recordHash !== cachedRecordHash) {
                    // This is an updated record
                    changes.updated.push({
                        ...record,
                        id: `${record.id}.${timestamp}`,
                        _id: record.id,
                        _hash: recordHash,
                    });
                }
            }
            else {
                // This is a new record
                changes.created.push({
                    ...record,
                    id: `${record.id}.${timestamp}`,
                    _id: record.id,
                    _hash: recordHash,
                });
            }
        }
        changes.all = [...changes.created, ...changes.updated];
        // cache the changes
        this.changes = changes;
        return this.changes;
    }
    getTimestamp() {
        return new Date().getTime();
    }
    /**
     * Save to the cache
     *
     * Note: Should be called after each poll to update the deduper cache.
     *
     */
    async persistChanges(currentRecords) {
        const records = this.getRecords(currentRecords);
        const data = lodash_1.default.merge({}, this.cache, records);
        await this.storage.save(data);
        return true;
    }
    /**
     * Hash a record
     */
    hash(record) {
        return object_hash_1.default(record, {
            algorithm: "md5",
            encoding: "base64",
        });
    }
    /**
     * Convert records into cache records
     *
     */
    getRecords(currentRecords) {
        const records = lodash_1.default.reduce(currentRecords, (records, record) => {
            records[record.id] = this.hash(record);
            return records;
        }, {});
        return records;
    }
}
exports.Deduper = Deduper;
/**
 * Get a deduper instance
 *
 * @param zapId Zap ID
 */
function getDeduper(zapId) {
    const storage = new storage_1.Storage(zapId);
    const deduper = new Deduper(storage);
    return deduper;
}
exports.getDeduper = getDeduper;
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