Add tests for the migrator

sally/lib/src/runtime/migration.dart

@@ -66,7 +66,7 @@ class Migrator {
     final sql = StringBuffer();
 
     // ignore: cascade_invocations
-    sql.write('ALTER TABLE ${table.$tableName} ADD COLUMN');
+    sql.write('ALTER TABLE ${table.$tableName} ADD COLUMN ');
     column.writeColumnDefinition(sql);
 
     return issueCustomQuery(sql.toString());

sally/test/migration_test.dart

@@ -0,0 +1,42 @@
+import 'package:mockito/mockito.dart';
+import 'package:sally/sally.dart';
+import 'package:test_api/test_api.dart';
+
+import 'generated_tables.dart';
+
+// used so that we can mock the SqlExecutor typedef
+abstract class SqlExecutorAsClass {
+  Future<void> call(String sql);
+}
+
+class MockQueryExecutor extends Mock implements SqlExecutorAsClass {}
+
+void main() {
+  Migrator migrator;
+  TestDatabase db;
+  MockQueryExecutor executor;
+
+  setUp(() {
+    executor = MockQueryExecutor();
+    db = TestDatabase(null);
+    migrator = Migrator(db, executor);
+  });
+
+  test('generates CREATE TABLE statements', () {
+    migrator.createAllTables();
+
+    verify(executor.call('CREATE TABLE IF NOT EXISTS users (id INTEGER NOT NULL , name VARCHAR NOT NULL , is_awesome BOOLEAN NULL CHECK (is_awesome in (0, 1)))'));
+  });
+
+  test('generates DROP TABLE statements', () {
+    migrator.deleteTable('users');
+
+    verify(executor.call('DROP TABLE IF EXISTS users'));
+  });
+
+  test('generates ALTER TABLE statements to add columns', () {
+    migrator.addColumn(db.users, db.users.isAwesome);
+
+    verify(executor.call('ALTER TABLE users ADD COLUMN is_awesome BOOLEAN NULL CHECK (is_awesome in (0, 1))'));
+  });
+}