Return if column is generated or not (#198)

* Return if column is generated or not

Related to
https://github.com/strongloop/loopback-datasource-juggler/issues/899

* add pk for testgen table

* Fixe the double quotes around generated

as requested by @loay

* Fix commit linter

Block must not be padded by blank lines padded-blocks

* Code fixes to follow guide

* Should fix the tests failing

Test failing on the tableName (incorrect case)

lib/discovery.js

@@ -165,7 +165,8 @@ function mixinDiscovery(MySQL, mysql) {
         ' numeric_precision AS "dataPrecision",' +
         ' numeric_scale AS "dataScale",' +
         ' column_type AS "columnType",' +
-        ' is_nullable = \'YES\' AS "nullable"' +
+        ' is_nullable = \'YES\' AS "nullable",' +
+        ' CASE WHEN extra LIKE \'%auto_increment%\' THEN 1 ELSE 0 END AS "generated"' +
         ' FROM information_schema.columns' +
         ' WHERE table_schema=' + mysql.escape(schema) +
         (table ? ' AND table_name=' + mysql.escape(table) : ''),
@@ -179,7 +180,8 @@ function mixinDiscovery(MySQL, mysql) {
         ' numeric_precision AS "dataPrecision",' +
         ' numeric_scale AS "dataScale",' +
         ' column_type AS "columnType",' +
-        ' is_nullable = \'YES\' AS "nullable"' +
+        ' is_nullable = \'YES\' AS "nullable",' +
+        ' CASE WHEN extra LIKE \'%auto_increment%\' THEN 1 ELSE 0 END AS "generated"' +
         ' FROM information_schema.columns' +
         (table ? ' WHERE table_name=' + mysql.escape(table) : ''),
         'table_name, ordinal_position', {});

test/mysql.discover.test.js

@@ -206,6 +206,31 @@ describe('Discover model foreign keys', function() {
   });
 });
 
+describe('Discover model generated columns', function() {
+  it('should return an array of columns for STRONGLOOP.PRODUCT and none of them is generated', function(done) {
+    db.discoverModelProperties('product', function(err, models) {
+      if (err) return done(err);
+      models.forEach(function(model) {
+        assert(model.tableName === 'product');
+        assert(!model.generated, 'STRONGLOOP.PRODUCT table should not have generated (identity) columns');
+      });
+      done();
+    });
+  });
+  it('should return an array of columns for STRONGLOOP.TESTGEN and the first is generated', function(done) {
+    db.discoverModelProperties('testgen', function(err, models) {
+      if (err) return done(err);
+      models.forEach(function(model) {
+        assert(model.tableName === 'testgen');
+        if (model.columnName === 'ID') {
+          assert(model.generated, 'STRONGLOOP.TESTGEN.ID should be a generated (identity) column');
+        }
+      });
+      done();
+    });
+  });
+});
+
 describe('Discover LDL schema from a table', function() {
   var schema;
   before(function(done) {

test/schema.sql

@@ -86,7 +86,7 @@ DROP TABLE IF EXISTS `INVENTORY_VIEW`;
 /*!50001 DROP VIEW IF EXISTS `INVENTORY_VIEW`*/;
 SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
-/*!50001 CREATE VIEW `INVENTORY_VIEW` AS SELECT 
+/*!50001 CREATE VIEW `INVENTORY_VIEW` AS SELECT
  1 AS `ID`,
  1 AS `PRODUCT_ID`,
  1 AS `PRODUCT_NAME`,
@@ -189,6 +189,20 @@ LOCK TABLES `RESERVATION` WRITE;
 /*!40000 ALTER TABLE `RESERVATION` ENABLE KEYS */;
 UNLOCK TABLES;
 
+--
+-- Table structure for table `TESTGEN`
+--
+
+DROP TABLE IF EXISTS `TESTGEN`;
+/*!40101 SET @saved_cs_client     = @@character_set_client */;
+/*!40101 SET character_set_client = utf8 */;
+CREATE TABLE `TESTGEN` (
+  `ID` int(11) NOT NULL  AUTO_INCREMENT,
+  `NAME` varchar(64) DEFAULT NULL,
+  PRIMARY KEY (`ID`)
+) ENGINE=MyISAM DEFAULT CHARSET=utf8;
+/*!40101 SET character_set_client = @saved_cs_client */;
+
 --
 -- Current Database: `STRONGLOOP`
 --