feat(sequelize): handle query string host value (#12041)

lib/sequelize.js

@@ -211,6 +211,13 @@ class Sequelize {
       }
 
       if (urlParts.query) {
+        // Allow host query argument to override the url host.
+        // Enables specifying domain socket hosts which cannot be specified via the typical
+        // host part of a url.
+        if (urlParts.query.host) {
+          options.host = urlParts.query.host;
+        }
+
         if (options.dialectOptions)
           Object.assign(options.dialectOptions, urlParts.query);
         else

test/unit/configuration.test.js

@@ -179,5 +179,12 @@ describe('Sequelize', () => {
       expect(dialectOptions.application_name).to.equal('client');
       expect(dialectOptions.ssl).to.equal('true');
     });
+
+    it('should use query string host if specified', () => {
+      const sequelize = new Sequelize('mysql://localhost:9821/dbname?host=example.com');
+
+      const options = sequelize.options;
+      expect(options.host).to.equal('example.com');
+    });
   });
 });