Allow configuration options for Postgres (#2873)

* Allow configuration options for Postgres

* Fix the use of incorrect options object.

* Refactor and test the postgres config parser.

* Remove unnecessary try/catch

* Remove unnecessary try/catch

* Add blank line at the end of the test file

* Rename file for consistency purposes

src/Adapters/Storage/Postgres/PostgresConfigParser.js

@@ -0,0 +1,53 @@
+const url = require('url');
+
+function getDatabaseOptionsFromURI(uri) {
+  const databaseOptions = {};
+
+  const parsedURI = url.parse(uri);
+  const queryParams = parseQueryParams(parsedURI.query);
+  const authParts = parsedURI.auth ? parsedURI.auth.split(':') : [];
+
+  databaseOptions.host = parsedURI.hostname || 'localhost';
+  databaseOptions.port = parsedURI.port ? parseInt(parsedURI.port) : 5432;
+  databaseOptions.database = parsedURI.pathname
+    ? parsedURI.pathname.substr(1)
+    : undefined;
+
+  databaseOptions.user = authParts.length > 0 ? authParts[0] : '';
+  databaseOptions.password = authParts.length > 1 ? authParts[1] : '';
+
+  databaseOptions.ssl =
+    queryParams.ssl && queryParams.ssl.toLowerCase() === 'true' ? true : false;
+  databaseOptions.binary =
+    queryParams.binary && queryParams.binary.toLowerCase() === 'true' ? true : false;
+
+  databaseOptions.client_encoding = queryParams.client_encoding;
+  databaseOptions.application_name = queryParams.application_name;
+  databaseOptions.fallback_application_name = queryParams.fallback_application_name;
+
+  if (queryParams.poolSize) {
+    databaseOptions.poolSize = parseInt(queryParams.poolSize) || 10;
+  }
+
+  return databaseOptions;
+}
+
+function parseQueryParams(queryString) {
+  queryString = queryString || '';
+
+  return queryString
+    .split('&')
+    .reduce((p, c) => {
+      const parts = c.split('=');
+      p[decodeURIComponent(parts[0])] =
+        parts.length > 1
+          ? decodeURIComponent(parts.slice(1).join('='))
+          : '';
+      return p;
+    }, {});
+}
+
+module.exports = {
+  parseQueryParams: parseQueryParams,
+  getDatabaseOptionsFromURI: getDatabaseOptionsFromURI
+};