fix: enable pool error handling

Signed-off-by: Matthew Gabeler-Lee <mgabeler-lee@6river.com>
Signed-off-by: SAMI BETTAYEB <sami3639@gmail.com>

Author: mgabeler-lee-6rs

lib/postgresql.js

@@ -54,7 +54,7 @@ exports.initialize = function initializeDataSource(dataSource, callback) {
  *
  * @param {PostgreSQL} postgresql PostgreSQL node.js binding
  * @options {Object} settings An object for the data source settings.
- * See [node-postgres documentation](https://github.com/brianc/node-postgres/wiki/Client#parameters).
+ * See [node-postgres documentation](https://node-postgres.com/api/client).
  * @property {String} url URL to the database, such as 'postgres://test:mypassword@localhost:5432/devdb'.
  * Other parameters can be defined as query string of the url
  * @property {String} hostname The host name or ip address of the PostgreSQL DB server
@@ -63,6 +63,8 @@ exports.initialize = function initializeDataSource(dataSource, callback) {
  * @property {String} password The password
  * @property {String} database The database name
  * @property {Boolean} ssl Whether to try SSL/TLS to connect to server
+ * @property {Function | string} [onError] Optional hook to connect to the pg pool 'error' event,
+ * or the string 'ignore' to record them with `debug` and otherwise ignore them.
  *
  * @constructor
  */
@@ -79,6 +81,16 @@ function PostgreSQL(postgresql, settings) {
   this.clientConfig.Promise = Promise;
   this.pg = new postgresql.Pool(this.clientConfig);
 
+  if (settings.onError) {
+    if (settings.onError === 'ignore') {
+      this.pg.on('error', function(err) {
+        debug(err);
+      });
+    } else {
+      this.pg.on('error', settings.onError);
+    }
+  }
+
   this.settings = settings;
   debug('Settings %j', settings);
 }

test/postgresql.initialization.test.js

@@ -83,4 +83,32 @@ describe('postgresql connector errors', function() {
       done();
     });
   });
+
+  it('honours onError=ignore', function() {
+    const settings = newConfig();
+    settings.onError = 'ignore';
+
+    const dataSource = new DataSource(connector, settings);
+
+    dataSource.connector.pg.listenerCount('error').should.equal(1);
+  });
+
+  it('honours onError=listener', function() {
+    const settings = newConfig();
+    let errorsCaught = 0;
+    settings.onError = function(err, client) {
+      err.should.be.ok();
+      client.should.be.ok();
+      ++errorsCaught;
+    };
+
+    const dataSource = new DataSource(connector, settings);
+
+    dataSource.connector.pg.listenerCount('error').should.equal(1);
+    dataSource.connector.pg.listeners('error').should.deepEqual([settings.onError]);
+
+    // send a fake error in and make sure it is bound to our listener
+    dataSource.connector.pg.emit('error', new Error('fake error'), {fakeClient: true});
+    errorsCaught.should.equal(1);
+  });
 });