More async/await changes

Author: jamesots

lib/src/results/results_impl.dart

@@ -31,14 +31,13 @@ class _ResultsImpl extends StreamView<Row> implements Results {
    * all the rows into a list until the stream has finished. It then returns a new
    * _ResultsImpl which wraps that list of rows.
    */
-  static Future<_ResultsImpl> destream(_ResultsImpl results) {
+  static Future<_ResultsImpl> destream(_ResultsImpl results) async {
     var rows = new List<Row>();
-    return results.forEach((row) {
+    await results.forEach((row) {
       rows.add(row);
-    }).then((_) {
-      var newStream = new Stream<Row>.fromIterable(rows);
-      return new _ResultsImpl._fromStream(results.insertId, results.affectedRows,
-        results.fields, newStream);
     });
+    var newStream = new Stream<Row>.fromIterable(rows);
+    return new _ResultsImpl._fromStream(results.insertId, results.affectedRows,
+      results.fields, newStream);
   }
 }

lib/src/retained_connection.dart

@@ -13,23 +13,20 @@ abstract class _RetainedConnectionBase extends Object with _ConnectionHelpers im
     return _cnx.processHandler(handler);
   }
 
-  Future<Query> prepare(String sql) {
+  Future<Query> prepare(String sql) async {
     _checkReleased();
     var query = new Query._forTransaction(new _TransactionPool(_cnx), _cnx, sql);
-    return query._prepare(true).then((preparedQuery) => new Future.value(query));
+    await query._prepare(true);
+    return new Future.value(query);
   }
 
-  Future<Results> prepareExecute(String sql, List parameters) {
+  Future<Results> prepareExecute(String sql, List parameters) async {
     _checkReleased();
-    return prepare(sql)
-      .then((query) {
-        return query.execute(parameters)
-          .then((results) {
-            //TODO is it right to close here? Query might still be running
-            query.close();
-            return new Future.value(results);
-          });
-      });
+    var query = await prepare(sql);
+    var results = await query.execute(parameters);
+    //TODO is it right to close here? Query might still be running
+    query.close();
+    return new Future.value(results);
   }
 
   void _checkReleased();

lib/src/transaction.dart

@@ -23,32 +23,28 @@ abstract class Transaction extends QueriableConnection {
 class _TransactionImpl extends _RetainedConnectionBase implements Transaction {
   _TransactionImpl._(cnx, pool) : super._(cnx, pool);
 
-  Future commit() {
+  Future commit() async {
     _checkReleased();
     _released = true;
 
     var handler = new _QueryStreamHandler("commit");
-    return _cnx.processHandler(handler)
-      .then((results) {
-        _cnx.inTransaction = false;
-        _cnx.release();
-        _pool._reuseConnectionForQueuedOperations(_cnx);
-        return results;
-      });
+    var results = await _cnx.processHandler(handler);
+    _cnx.inTransaction = false;
+    _cnx.release();
+    _pool._reuseConnectionForQueuedOperations(_cnx);
+    return results;
   }
 
-  Future rollback() {
+  Future rollback() async {
     _checkReleased();
     _released = true;
 
     var handler = new _QueryStreamHandler("rollback");
-    return _cnx.processHandler(handler)
-      .then((results) {
-        _cnx.inTransaction = false;
-        _cnx.release();
-        _pool._reuseConnectionForQueuedOperations(_cnx);
-        return results;
-      });
+    var results = await _cnx.processHandler(handler);
+    _cnx.inTransaction = false;
+    _cnx.release();
+    _pool._reuseConnectionForQueuedOperations(_cnx);
+    return results;
   }
 
   void _checkReleased() {