Reduce duplication when adding a new migration.

README.md

@@ -43,7 +43,7 @@ npm test
 
 1. Create `migrations/sql/NNN-your-migration-name.up.sql` with your change in SQL.
 2. Create `migrations/sql/NNN-your-migration-name.down.sql` with the rollback of your change in SQL.
-3. Run `db-migrate create your-migration-name` and edit the generated file to run the above SQL files.
+3. Run `db-migrate create your-migration-name` and edit the generated file to have this line: `module.exports = require('../lib/migrationRunner').create('NNN-your-migration-name');`
 4. Run `npm run db-migrate-up`.
 5. Generate LB artifact using `scripts/generate-liquibase-artifact` (TODO: make this internal)
 

lib/migrationRunner.js

@@ -0,0 +1,18 @@
+var fs   = require('fs');
+var util = require('util');
+var path = require('path');
+
+var runMigration = function(path, db, callback) {
+    db.runSql(fs.readFileSync(path, {encoding: 'utf8'}), callback);
+};
+
+module.exports = {
+    create: function (name) {
+        var format = path.resolve(__dirname, '../migrations/sql/%s.%s.sql');
+
+        return {
+            up: runMigration.bind(null, util.format(format, name, 'up')),
+            down: runMigration.bind(null, util.format(format, name, 'down'))
+        };
+    }
+};

migrations/20141020151056-initial-schema.js

@@ -1,12 +1 @@
-var fs   = require('fs');
+module.exports = require('../lib/migrationRunner').create('001-initial-schema');
-var util = require('util');
-var path = require('path').resolve(__dirname, 'sql/001-initial-schema.%s.sql');
-
-exports.up = function(db, callback) {
-    var content = fs.readFileSync(util.format(path, 'up'), {encoding: 'utf8'});
-    db.runSql(content, callback);
-};
-
-exports.down = function(db, callback) {
-    db.runSql(fs.readFileSync(util.format(path, 'down'), {encoding: 'utf8'}), callback);
-};