feat(cli): add lifecycle support for datasources

Implements #3675
loopbackio · Sep 10, 2019 · 8573173 · 8573173
1 parent 7034bb0
commit 8573173
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Showing 2 changed files with 46 additions and 4 deletions.
diff --git a/packages/cli/generators/datasource/templates/datasource.ts.ejs b/packages/cli/generators/datasource/templates/datasource.ts.ejs
@@ -1,8 +1,15 @@
-import {inject} from '@loopback/core';
+import {
+  inject,
+  lifeCycleObserver,
+  LifeCycleObserver,
+  ValueOrPromise,
+} from '@loopback/core';
 import {juggler} from '@loopback/repository';
 import * as config from './<%= jsonFileName %>';
 
-export class <%= className %>DataSource extends juggler.DataSource {
+@lifeCycleObserver('datasource')
+export class <%= className %>DataSource extends juggler.DataSource
+  implements LifeCycleObserver {
   static dataSourceName = '<%= name %>';
 
   constructor(
@@ -11,4 +18,19 @@ export class <%= className %>DataSource extends juggler.DataSource {
   ) {
     super(dsConfig);
   }
+
+  /**
+   * Start the datasource when application is started
+   */
+  start(): ValueOrPromise<void> {
+    // Add your logic here to be invoked when the application is started
+  }
+
+  /**
+   * Disconnect the datasource when application is stopped. This allows the
+   * application to be shut down gracefully.
+   */
+  stop(): ValueOrPromise<void> {
+    return super.disconnect();
+  }
 }
diff --git a/packages/cli/test/integration/generators/datasource.integration.js b/packages/cli/test/integration/generators/datasource.integration.js
@@ -159,7 +159,24 @@ function checkBasicDataSourceFiles() {
   assert.file(expectedIndexFile);
   assert.noFile(path.join(SANDBOX_PATH, 'node_modules/memory'));
 
-  assert.fileContent(expectedTSFile, /import {inject} from '@loopback\/core';/);
+  /*
+  import {
+    inject,
+    lifeCycleObserver,
+    LifeCycleObserver,
+    ValueOrPromise,
+  } from '@loopback/core';
+  */
+  assert.fileContent(
+    expectedTSFile,
+    `import {
+  inject,
+  lifeCycleObserver,
+  LifeCycleObserver,
+  ValueOrPromise,
+} from '@loopback/core';`,
+  );
+
   assert.fileContent(
     expectedTSFile,
     /import {juggler} from '@loopback\/repository';/,
@@ -168,10 +185,12 @@ function checkBasicDataSourceFiles() {
     expectedTSFile,
     /import \* as config from '.\/ds.datasource.json';/,
   );
+  assert.fileContent(expectedTSFile, /@lifeCycleObserver\('datasource'\)/);
   assert.fileContent(
     expectedTSFile,
-    /export class DsDataSource extends juggler.DataSource {/,
+    /export class DsDataSource extends juggler.DataSource/,
   );
+  assert.fileContent(expectedTSFile, /implements LifeCycleObserver {/);
   assert.fileContent(expectedTSFile, /static dataSourceName = 'ds';/);
   assert.fileContent(expectedTSFile, /constructor\(/);
   assert.fileContent(
@@ -180,6 +199,7 @@ function checkBasicDataSourceFiles() {
   );
   assert.fileContent(expectedTSFile, /\) \{/);
   assert.fileContent(expectedTSFile, /super\(dsConfig\);/);
+  assert.fileContent(expectedTSFile, /stop\(\)\: ValueOrPromise<void>/);
 
   assert.fileContent(expectedIndexFile, /export \* from '.\/ds.datasource';/);
 }