feat(parser): add schema envelopes (#1815)

* first envelope

* add abstract class

* add tests

* add more tests

* fix tests

* add envelopes

* add middy parser

* minor schema changes

* add more envelopes and tests, refactored utils to autocomplete event files

* simplified check

* remove middleware from this branch

* refactored from class to function envelopes

* removed parser tests, should be in another branch

* add parser to pre push

* consistent naming

Author: am29d

.husky/pre-push

@@ -7,4 +7,5 @@ npm t \
   -w packages/metrics \
   -w packages/tracer \
   -w packages/idempotency \
-  -w packages/parameters
+  -w packages/parameters \
+  -w packages/parser

package-lock.json

@@ -60,8 +60,11 @@
     "serverless",
     "nodejs"
   ],
-
   "peerDependencies": {
     "zod": ">=3.x"
+  },
+  "devDependencies": {
+    "@anatine/zod-mock": "^3.13.3",
+    "@faker-js/faker": "^8.3.1"
   }
-}
+}

packages/parser/package.json

@@ -0,0 +1,18 @@
+import { parse } from './envelope.js';
+import { z, ZodSchema } from 'zod';
+import { APIGatewayProxyEventSchema } from '../schemas/apigw.js';
+
+/**
+ * API Gateway envelope to extract data within body key
+ */
+export const apiGatewayEnvelope = <T extends ZodSchema>(
+  data: unknown,
+  schema: T
+): z.infer<T> => {
+  const parsedEnvelope = APIGatewayProxyEventSchema.parse(data);
+  if (!parsedEnvelope.body) {
+    throw new Error('Body field of API Gateway event is undefined');
+  }
+
+  return parse(parsedEnvelope.body, schema);
+};

packages/parser/src/envelopes/apigw.ts

@@ -0,0 +1,18 @@
+import { parse } from './envelope.js';
+import { z, ZodSchema } from 'zod';
+import { APIGatewayProxyEventV2Schema } from '../schemas/apigwv2.js';
+
+/**
+ * API Gateway V2 envelope to extract data within body key
+ */
+export const apiGatewayV2Envelope = <T extends ZodSchema>(
+  data: unknown,
+  schema: T
+): z.infer<T> => {
+  const parsedEnvelope = APIGatewayProxyEventV2Schema.parse(data);
+  if (!parsedEnvelope.body) {
+    throw new Error('Body field of API Gateway event is undefined');
+  }
+
+  return parse(parsedEnvelope.body, schema);
+};

packages/parser/src/envelopes/apigwv2.ts

@@ -0,0 +1,23 @@
+import { parse } from './envelope.js';
+import { z, ZodSchema } from 'zod';
+import { CloudWatchLogsSchema } from '../schemas/cloudwatch.js';
+
+/**
+ * CloudWatch Envelope to extract a List of log records.
+ *
+ *  The record's body parameter is a string (after being base64 decoded and gzipped),
+ *  though it can also be a JSON encoded string.
+ *  Regardless of its type it'll be parsed into a BaseModel object.
+ *
+ *  Note: The record will be parsed the same way so if model is str
+ */
+export const cloudWatchEnvelope = <T extends ZodSchema>(
+  data: unknown,
+  schema: T
+): z.infer<T> => {
+  const parsedEnvelope = CloudWatchLogsSchema.parse(data);
+
+  return parsedEnvelope.awslogs.data.logEvents.map((record) => {
+    return parse(record.message, schema);
+  });
+};

packages/parser/src/envelopes/cloudwatch.ts

@@ -0,0 +1,28 @@
+import { parse } from './envelope.js';
+import { z, ZodSchema } from 'zod';
+import { DynamoDBStreamSchema } from '../schemas/dynamodb.js';
+
+type DynamoDBStreamEnvelopeResponse<T extends ZodSchema> = {
+  NewImage: z.infer<T>;
+  OldImage: z.infer<T>;
+};
+
+/**
+ * DynamoDB Stream Envelope to extract data within NewImage/OldImage
+ *
+ * Note: Values are the parsed models. Images' values can also be None, and
+ * length of the list is the record's amount in the original event.
+ */
+export const dynamoDDStreamEnvelope = <T extends ZodSchema>(
+  data: unknown,
+  schema: T
+): DynamoDBStreamEnvelopeResponse<T>[] => {
+  const parsedEnvelope = DynamoDBStreamSchema.parse(data);
+
+  return parsedEnvelope.Records.map((record) => {
+    return {
+      NewImage: parse(record.dynamodb.NewImage, schema),
+      OldImage: parse(record.dynamodb.OldImage, schema),
+    };
+  });
+};

packages/parser/src/envelopes/dynamodb.ts

@@ -0,0 +1,23 @@
+import { z, ZodSchema } from 'zod';
+
+/**
+ * Abstract function to parse the content of the envelope using provided schema.
+ * Both inputs are provided as unknown by the user.
+ * We expect the data to be either string that can be parsed to json or object.
+ * @internal
+ * @param data data to parse
+ * @param schema schema
+ */
+export const parse = <T extends ZodSchema>(
+  data: unknown,
+  schema: T
+): z.infer<T>[] => {
+  if (typeof data === 'string') {
+    return schema.parse(JSON.parse(data));
+  } else if (typeof data === 'object') {
+    return schema.parse(data);
+  } else
+    throw new Error(
+      `Invalid data type for envelope. Expected string or object, got ${typeof data}`
+    );
+};

packages/parser/src/envelopes/envelope.ts

@@ -0,0 +1,13 @@
+import { parse } from './envelope.js';
+import { z, ZodSchema } from 'zod';
+import { EventBridgeSchema } from '../schemas/eventbridge.js';
+
+/**
+ * Envelope for EventBridge schema that extracts and parses data from the `detail` key.
+ */
+export const eventBridgeEnvelope = <T extends ZodSchema>(
+  data: unknown,
+  schema: T
+): z.infer<T> => {
+  return parse(EventBridgeSchema.parse(data).detail, schema);
+};

packages/parser/src/envelopes/eventbridge.ts

@@ -0,0 +1,39 @@
+import { z, ZodSchema } from 'zod';
+import { parse } from './envelope.js';
+import {
+  KafkaMskEventSchema,
+  KafkaSelfManagedEventSchema,
+} from '../schemas/kafka.js';
+import { type KafkaRecord } from '../types/schema.js';
+
+/**
+ * Kafka event envelope to extract data within body key
+ * The record's body parameter is a string, though it can also be a JSON encoded string.
+ * Regardless of its type it'll be parsed into a BaseModel object.
+ *
+ * Note: Records will be parsed the same way so if model is str,
+ * all items in the list will be parsed as str and not as JSON (and vice versa)
+ */
+export const kafkaEnvelope = <T extends ZodSchema>(
+  data: unknown,
+  schema: T
+): z.infer<T> => {
+  // manually fetch event source to deside between Msk or SelfManaged
+
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore
+  const eventSource = data['eventSource'];
+
+  const parsedEnvelope:
+    | z.infer<typeof KafkaMskEventSchema>
+    | z.infer<typeof KafkaSelfManagedEventSchema> =
+    eventSource === 'aws:kafka'
+      ? KafkaMskEventSchema.parse(data)
+      : KafkaSelfManagedEventSchema.parse(data);
+
+  return Object.values(parsedEnvelope.records).map((topicRecord) => {
+    return topicRecord.map((record: KafkaRecord) => {
+      return parse(record.value, schema);
+    });
+  });
+};