[Issue #228] consumers to add model hooks

doc/usage.md

@@ -55,6 +55,22 @@ It defaults to `v1.0` and the default endpoint URLs are of the form:
 
     https://<host-url>/v1.0/<api-endpoint>
 
+Additionally, there is an optional `hooks` object that let's you define database hooks. This is an example of a database hook that adds a property to a Things instance that is being created:
+```
+const config = {
+  db: {
+    hooks: {
+      'beforeCreate': (instance, options) => {
+        if (instance.$modelOptions.name.plural === 'Things') {
+          instance.properties = Object.assign({}, instance.properties, {
+            customProperty: 'custom property value'
+          });
+        }
+      }
+    }
+  }
+};
+```
 For more details about the API you can check this [document](https://github.com/mozilla-sensorweb/sensorthings/blob/master/doc/API.md).
 
 ## Example requests

src/models/db.js

@@ -63,7 +63,10 @@ export default config => {
     host,
     port,
     dialect: 'postgres',
-    logging: false
+    logging: false,
+    define: {
+      hooks: config.hooks
+    }
   });
 
   db = {};

test/server.js

@@ -7,16 +7,45 @@ let app = express();
 app.use(bodyParser.urlencoded({ extended: false }));
 app.use(bodyParser.json());
 
+let hooks = {};
 const config = {
   db: {
     host: 'localhost',
     port: 5432,
     name: 'sensorthingstest',
     user: 'postgres',
-    pass: '12345678'
+    pass: '12345678',
+    hooks: {
+        beforeCreate: () => {
+          hooks.beforeCreate = true
+        },
+        afterCreate: () => {
+          hooks.afterCreate = true
+        },
+        beforeDestroy: () => {
+          hooks.beforeDestroy = true
+        },
+        afterDestroy: () => {
+          hooks.afterDestroy = true
+        },
+        beforeUpdate: () => {
+          hooks.beforeUpdate = true
+        },
+        afterUpdate: () => {
+          hooks.afterUpdate = true
+        }
+    }
   }
-};
+}
 
 app.use('/', SensorThings(config));
 
-exports = module.exports = app;
+export default app;
+
+exports.resetHooks = () => {
+  hooks = {}
+};
+
+exports.hookInvoked = name => {
+  return hooks[name] !== undefined
+};

test/test_client_db_hooks.js

@@ -0,0 +1,73 @@
+import db         from '../src/models/db';
+import * as CONST from './constants';
+import { hookInvoked, resetHooks } from './server';
+
+// Database hooks (sequelize)
+const dbHooks = [
+  'beforeCreate',
+  'afterCreate',
+  'beforeDestroy',
+  'afterDestroy',
+  'beforeUpdate',
+  'afterUpdate'
+];
+
+db().then(models => {
+  describe('Database hooks', () => {
+    beforeEach(() => {
+      resetHooks();
+      return models.sequelize.transaction(transaction => {
+        return Promise.all(Object.keys(CONST.entities).map(name => {
+          return models[name].destroy({ transaction, where: {} });
+        }));
+      });
+    });
+
+    Object.keys(CONST.entities).forEach(entity => {
+      it(entity + ' "create" hooks', done => {
+        models[entity].create(CONST[entity + 'Entity']).then(() => {
+          dbHooks.slice(0, 2).forEach(hook => {
+            hookInvoked(hook).should.be.true();
+          });
+          done();
+        });
+      })
+    });
+
+    // These tests fail. See:
+    // https://github.com/mozilla-sensorweb/sensorthings/issues/246
+    Object.keys(CONST.entities).forEach(entity => {
+      xit(entity + ' "destroy" hooks', done => {
+      models[entity].create(CONST[entity + 'Entity']).then(
+        instance => {
+          const id = instance.id;
+          models[entity].destroy({
+            where: { id } }).then(() => {
+            dbHooks.slice(2, 4).forEach(hook => {
+              hookInvoked(hook).should.be.true();
+            });
+            done();
+          });
+        });
+      })
+    });
+
+    Object.keys(CONST.entities).forEach(entity => {
+      it(entity + ' "update" hooks', done => {
+      models[entity].create(CONST[entity + 'Entity']).then(
+        instance => {
+          models[entity].update({ name: 'newname' }, {
+            where: { id: instance.id },
+            individualHooks: true
+          }).then(() => {
+            dbHooks.slice(4).forEach(hook => {
+              hookInvoked(hook).should.be.true();
+            });
+            done();
+          });
+        });
+      })
+    });
+  });
+});
+