Implemented extra boolean param for rollback() (#2968)

* Implemented extra boolean param for rollback()
Extra parameter allows all migrations to be rolled back.

* Removed spurious log

* Removed stray debugger instruction

* Moved to arrow functions

src/migrate/Migrator.js

@@ -99,8 +99,8 @@ export default class Migrator {
       });
   }
 
-  // Rollback the last "batch" of migrations that were run.
-  rollback(config) {
+  // Rollback the last "batch", or all, of migrations that were run.
+  rollback(config, all = false) {
     return Promise.try(() => {
       this.config = getMergedConfig(config, this.config);
 
@@ -109,7 +109,7 @@ export default class Migrator {
         .tap((value) =>
           validateMigrationList(this.config.migrationSource, value)
         )
-        .then((val) => this._getLastBatch(val))
+        .then((val) => (all ? val[0] : this._getLastBatch(val)))
         .then((migrations) => {
           return this._runBatch(migrations, 'down');
         });

test/integration/migrate/index.js

@@ -331,6 +331,53 @@ module.exports = function(knex) {
       });
     });
 
+    describe('knex.migrate.rollback - all', () => {
+      before(() => {
+        return knex.migrate
+          .latest({
+            directory: ['test/integration/migrate/test'],
+          })
+          .then(function() {
+            return knex.migrate.latest({
+              directory: [
+                'test/integration/migrate/test',
+                'test/integration/migrate/test2',
+              ],
+            });
+          });
+      });
+
+      it('should delete all batches from the migration log', () => {
+        return knex.migrate
+          .rollback(
+            {
+              directory: [
+                'test/integration/migrate/test',
+                'test/integration/migrate/test2',
+              ],
+            },
+            true
+          )
+          .spread(function(batchNo, log) {
+            expect(batchNo).to.equal(2);
+            expect(log).to.have.length(4);
+            return knex('knex_migrations')
+              .select('*')
+              .then(function(data) {
+                expect(data.length).to.equal(0);
+              });
+          });
+      });
+
+      it('should drop tables as specified in the batch', () => {
+        return Promise.map(tables, function(table) {
+          return knex.schema.hasTable(table).then(function(exists) {
+            expect(!!exists).to.equal(false);
+          });
+        });
+      });
+    });
+
     after(function() {
       rimraf.sync(path.join(__dirname, './migration'));
     });

types/knex.d.ts

@@ -829,7 +829,7 @@ declare namespace Knex {
   interface Migrator {
     make(name: string, config?: MigratorConfig): Bluebird<string>;
     latest(config?: MigratorConfig): Bluebird<any>;
-    rollback(config?: MigratorConfig): Bluebird<any>;
+    rollback(config?: MigratorConfig, all?: boolean): Bluebird<any>;
     status(config?: MigratorConfig): Bluebird<number>;
     currentVersion(config?: MigratorConfig): Bluebird<string>;
   }