@alexknips/nestjs-kafka-events/dist/serializer/kafka.serializer.js

Lightweight, tested, straight-forward wrapper around KafkaJS and Confluent's Schema Registry.

"use strict";
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var __asyncValues = (this && this.__asyncValues) || function (o) {
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Object.defineProperty(exports, "__esModule", { value: true });
exports.KafkaSerializer = void 0;
const confluent_schema_registry_1 = require("@kafkajs/confluent-schema-registry");
const common_1 = require("@nestjs/common");
const topic_subject_helper_1 = require("../helpers/topic-subject.helper");
const loggers_1 = require("../loggers");
let KafkaSerializer = class KafkaSerializer {
    constructor(kafkaLogger) {
        this.kafkaLogger = kafkaLogger;
        this.schemas = new Map();
    }
    async initialize(configuration, topics) {
        this.schemaRegistry = new confluent_schema_registry_1.SchemaRegistry(configuration.api, configuration === null || configuration === void 0 ? void 0 : configuration.options);
        await this.fetchAllSchemaIds(topics);
    }
    async fetchAllSchemaIds(topics) {
        var e_1, _a;
        try {
            for (var topics_1 = __asyncValues(topics), topics_1_1; topics_1_1 = await topics_1.next(), !topics_1_1.done;) {
                const topic = topics_1_1.value;
                await this.fetchSchemaIds(topic);
            }
        }
        catch (e_1_1) { e_1 = { error: e_1_1 }; }
        finally {
            try {
                if (topics_1_1 && !topics_1_1.done && (_a = topics_1.return)) await _a.call(topics_1);
            }
            finally { if (e_1) throw e_1.error; }
        }
    }
    async fetchSchemaIds(topic) {
        try {
            const keyId = await (async () => {
                try {
                    const x = (await this.schemaRegistry.getLatestSchemaId((0, topic_subject_helper_1.getSchemaRegistryKeySubjectByTopic)(topic))) || null;
                    return x;
                }
                catch (error) {
                    return null;
                }
            })();
            const valueId = await this.schemaRegistry.getLatestSchemaId((0, topic_subject_helper_1.getSchemaRegistryValueSubjectByTopic)(topic));
            this.schemas.set(topic, {
                keyId,
                valueId,
            });
        }
        catch (reject) {
            this.kafkaLogger.error(`Error while fetching schema ids for topic ${topic}`, reject);
            throw reject;
        }
    }
    async serialize(value) {
        const ids = this.schemas.get(value.topic);
        if (!ids) {
            this.kafkaLogger.error(`Trying to serialize message in topic ${value.topic} failed: No schema ids found.`);
            return undefined;
        }
        try {
            const message = {
                value: await this.schemaRegistry.encode(ids.valueId, value.event),
                partition: value === null || value === void 0 ? void 0 : value.partition,
                headers: value === null || value === void 0 ? void 0 : value.headers,
                timestamp: value === null || value === void 0 ? void 0 : value.timestamp,
            };
            if (ids === null || ids === void 0 ? void 0 : ids.keyId) {
                message['key'] = await this.schemaRegistry.encode(ids.keyId, value.key);
            }
            else {
                if (value.key && typeof value.key === 'string') {
                    message['key'] = value.key;
                }
            }
            return message;
        }
        catch (reject) {
            this.kafkaLogger.error(`Error while serializing message: ${JSON.stringify(value)}`, reject);
            throw reject;
        }
    }
};
KafkaSerializer = __decorate([
    (0, common_1.Injectable)(),
    __metadata("design:paramtypes", [loggers_1.KafkaLogger])
], KafkaSerializer);
exports.KafkaSerializer = KafkaSerializer;
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