refactor(datasource): add check for supported connectors

Author: shubhamp-sf

package-lock.json

@@ -25,7 +25,7 @@
     "eslint": "lb-eslint --report-unused-disable-directives .",
     "eslint:fix": "npm run eslint -- --fix",
     "pretest": "npm run rebuild",
-    "test": "echo 'No Tests'",
+    "test": "lb-mocha --allow-console-logs \"dist/__tests__\"",
     "posttest": "npm run lint",
     "test:dev": "lb-mocha --allow-console-logs dist/__tests__/**/*.js && npm run posttest",
     "clean": "lb-clean dist *.tsbuildinfo .eslintcache",

package.json

@@ -0,0 +1,18 @@
+import {expect} from '@loopback/testlab';
+import {SequelizeDataSource} from '../../sequelize';
+import {SupportedLoopbackConnectors} from '../../sequelize/connector-mapping';
+
+describe('Sequelize DataSource', () => {
+  it('throws error when nosql connectors are supplied', () => {
+    try {
+      new SequelizeDataSource({
+        user: 'test',
+        password: 'secret',
+        connector: 'memory' as SupportedLoopbackConnectors,
+      });
+    } catch (err) {
+      const result = err.message;
+      expect(result).which.eql('Specified connector memory is not supported.');
+    }
+  });
+});

src/__tests__/unit/sequelize.datasource.unit.ts

@@ -0,0 +1,16 @@
+import {Dialect as AllSequelizeDialects} from 'sequelize';
+
+export type SupportedLoopbackConnectors = "mysql" | "postgresql" | "oracle" | "sqlite3" | "db2";
+/**
+ * @key Loopback connectors name supported by this extension
+ * @value Equivalent Dialect in Sequelize
+ */
+export const SupportedConnectorMapping: {
+  [key in SupportedLoopbackConnectors]?: AllSequelizeDialects;
+} = {
+  "mysql": "mysql",
+  "postgresql": "postgres",
+  "oracle": "oracle",
+  "sqlite3" : "sqlite",
+  "db2": "db2",
+};

src/sequelize/connector-mapping.ts

@@ -1,23 +1,35 @@
 import {LifeCycleObserver} from '@loopback/core';
 import {juggler} from '@loopback/repository';
 import {Options as SequelizeOptions, Sequelize} from 'sequelize';
+import {
+  SupportedConnectorMapping as supportedConnectorMapping,
+  SupportedLoopbackConnectors,
+} from './connector-mapping';
 
 export class SequelizeDataSource
   extends juggler.DataSource
   implements LifeCycleObserver
 {
-  constructor(public config: SequelizeOptions & {user?: string}) {
+  constructor(public config: SequelizeDataSourceConfig) {
     super(config);
+
+    if (!(this.config.connector in supportedConnectorMapping)) {
+      throw new Error(
+        `Specified connector ${
+          this.config.connector ?? this.config.dialect
+        } is not supported.`,
+      );
+    }
   }
+
   sequelize?: Sequelize;
-  async init(...injectedArgs: unknown[]): Promise<void> {
-    console.log('injected args', injectedArgs);
-    console.log('init called');
+  async init(): Promise<void> {
     this.sequelize = new Sequelize({
       host: this.config.host,
       port: this.config.port,
       database: this.config.database,
-      dialect: 'postgres',
+      dialect:
+        supportedConnectorMapping[this.config.connector ?? this.config.dialect],
       username: this.config.user ?? this.config.username,
       password: this.config.password,
       logging: console.log,
@@ -33,3 +45,8 @@ export class SequelizeDataSource
     this.sequelize?.close?.().catch(console.log);
   }
 }
+
+export type SequelizeDataSourceConfig = SequelizeOptions & {
+  user?: string;
+  connector: SupportedLoopbackConnectors;
+};