fix: Fix types and builder.build() return design

README.md

@@ -14,6 +14,9 @@ The library is a wrapper for the `Ajv` instance, which is in turn used in conjun
 - Allows retrieval of `Ajv` validation errors for the payload data by pulling them up to the application level.
 - Resolves the `TypeError` when passing an `Ajv` instance to the SchemaRegistry constructor options.
 
+#### Bonus Features
+- Saves you from having to handle the schema ID.
+
 ## Installation
 
 Install the library:
@@ -53,7 +56,7 @@ const builder = new SchemaRegistryAjvBuilder({
   },
 });
 
-const [ajvInstance, getErrors] = await builder.build();
+const { ajvInstance, getSchemaId, getErrors } = await builder.build();
 
 const schemaRegistry = new SchemaRegistry({ 
   host: 'https://schema-registry.example.com:8081',
@@ -70,13 +73,13 @@ Somewhere in your code:
 // Publishing to Kafka topic
 try {
   // To encode Kafka message value
-  const value = await schemaRegistry.encode(builder.getSchemaId(), event);
+  const value = await schemaRegistry.encode(getSchemaId(), event);
 
   // ...
 } catch (err) {
   // To get Ajv validation errors
   const validationErorrs = getErrors();
-  
+
   // ...
 }
 ```

package.json

@@ -10,6 +10,10 @@
     "name": "Sylvanas Cry",
     "email": "sylvanas@gmx.us"
   },
+  "contributors": [{
+    "name": "Ilia Smirnov",
+    "email": "smirnov.i.o@yandex.ru"
+  }],
   "keywords": [
     "confluent schema registry",
     "schema-registry",

src/schema-registry-ajv-builder.spec.ts

@@ -77,11 +77,11 @@ describe('SchemaRegistryAjvBuilder', () => {
     createVersionsScope(200, [1, 2, 3], headers);
     createSchemaScope(3, 200, schemaReply, headers);
 
-    const [ajv] = await builder.build();
+    const { ajvInstance } = await builder.build();
 
-    expect(ajv).toBeInstanceOf(SchemaRegistryAjv);
-    expect(ajv.addSchema(schema)).toBeInstanceOf(Ajv2020);
-    expect(typeof ajv.compile(schema)).toBe('function');
+    expect(ajvInstance).toBeInstanceOf(SchemaRegistryAjv);
+    expect(ajvInstance.addSchema(schema)).toBeInstanceOf(Ajv2020);
+    expect(typeof ajvInstance.compile(schema)).toBe('function');
   });
 
   it('it should provide SchemaRegistry comfortable Ajv instance', async () => {
@@ -90,10 +90,10 @@ describe('SchemaRegistryAjvBuilder', () => {
     createVersionsScope(200, [1, 2, 3], headers);
     createSchemaScope(3, 200, schemaReply, headers);
 
-    const [ajv] = await builder.build();
+    const { ajvInstance } = await builder.build();
     const schemaRegistry = new SchemaRegistry({
       host,
-    }, { [SchemaType.JSON]: { ajvInstance: ajv } });
+    }, { [SchemaType.JSON]: { ajvInstance } });
 
     expect(schemaRegistry).toBeInstanceOf(SchemaRegistry);
   });
@@ -113,8 +113,8 @@ describe('SchemaRegistryAjvBuilder', () => {
       id: 1,
     }, headers);
 
-    await builder.build();
-    expect(builder.getSchemaId()).toBe(1);
+    const { getSchemaId } = await builder.build();
+    expect(getSchemaId()).toBe(1);
   });
 
   it('should return a latest schema id', async () => {
@@ -123,8 +123,8 @@ describe('SchemaRegistryAjvBuilder', () => {
     createVersionsScope(200, [1, 2, 3], headers);
     createSchemaScope(3, 200, schemaReply, headers);
 
-    await builder.build();
-    expect(builder.getSchemaId()).toBe(3);
+    const { getSchemaId } = await builder.build();
+    expect(getSchemaId()).toBe(3);
   });
 
   it('should return a default latest schema id', async () => {
@@ -142,8 +142,8 @@ describe('SchemaRegistryAjvBuilder', () => {
       id: 6,
     }, headers);
 
-    await builder.build();
-    expect(builder.getSchemaId()).toBe(6);
+    const { getSchemaId } = await builder.build();
+    expect(getSchemaId()).toBe(6);
   });
 
   it('should return validation errors', async () => {
@@ -152,8 +152,8 @@ describe('SchemaRegistryAjvBuilder', () => {
     createVersionsScope(200, [1, 2, 3], headers);
     createSchemaScope(3, 200, schemaReply, headers);
 
-    const [ajv, getErrors] = await builder.build();
-    const validate = ajv.compile({});
+    const { ajvInstance, getErrors } = await builder.build();
+    const validate = ajvInstance.compile({});
     const isValid = validate({
       attribute: 'BROKEN',
       custom: 'value',

src/schema-registry-ajv-builder.ts

@@ -3,10 +3,7 @@ import addFormats from 'ajv-formats';
 import axios from 'axios';
 import { SchemaRegistryAjvSchemaException, SchemaRegistryAjvVersionException } from './exceptions';
 import { SchemaRegistryAjv } from './schema-registry-ajv';
-import {
-  SchemaRegistryAjvBuilderBuildReturn,
-  SchemaRegistryAjvBuilderOptions,
-} from './schema-registry-ajv-builder.types';
+import { BuildReturnType, SchemaRegistryAjvBuilderOptions } from './schema-registry-ajv-builder.types';
 
 export class SchemaRegistryAjvBuilder {
   /**
@@ -40,7 +37,7 @@ export class SchemaRegistryAjvBuilder {
     };
   }
 
-  public async build(): Promise<SchemaRegistryAjvBuilderBuildReturn> {
+  public async build(): Promise<BuildReturnType> {
     const { ajvClass, ajvFormats, schemaRegistry } = this.options;
     const version = typeof schemaRegistry.version === 'number'
       ? schemaRegistry.version
@@ -61,17 +58,11 @@ export class SchemaRegistryAjvBuilder {
     const validate = ajv.compile(schema);
     this.validate = validate;
 
-    return [
-      new SchemaRegistryAjv(ajv, validate),
-      () => this.validate.errors,
-    ];
-  }
-
-  /**
-   * Returns schema id.
-   */
-  public getSchemaId(): number {
-    return this.schemaId;
+    return {
+      ajvInstance: new SchemaRegistryAjv(ajv, validate),
+      getErrors: () => this.validate.errors,
+      getSchemaId: () => this.schemaId,
+    };
   }
 
   private async getSchema(version: number): Promise<AnySchema> {

src/schema-registry-ajv-builder.types.ts

@@ -15,17 +15,32 @@ export interface AjvCustomFormat {
   format: Format;
 }
 
-export type GetErrorsFunction = () => ValidateFunction['errors'];
+export type GetSchemaId = () => number;
+export type GetErrors = () => ValidateFunction['errors'];
 
-export type SchemaRegistryAjvBuilderBuildReturn = [
-  SchemaRegistryAjvInstance,
-  GetErrorsFunction,
-];
+export interface BuildReturnType {
+  /**
+   * SchemaRegistry constructor compatible Ajv instance.
+   *
+   * @see {import('@kafkajs/confluent-schema-registry/dist/@types').JsonOptions}
+   */
+  ajvInstance: SchemaRegistryAjvInstance;
+
+  /**
+   * Returns schema id.
+   */
+  getSchemaId: GetSchemaId;
+
+  /**
+   * Returns Ajv validation errors.
+   */
+  getErrors: GetErrors;
+}
 
 export interface SchemaRegistryAjvBuilderSchemaRegistryOptions {
   /**
    * Schema Registry URI.
-   **
+   *
    * @example https://schema-registry.example.com
    * @example http://localhost:8081
    * @example http://localhost:8081/