Add migrator test for migrate:down

test/integration/migrate/index.js

@@ -582,6 +582,72 @@ module.exports = function(knex) {
       });
     });
 
+    describe('knex.migrate.down', () => {
+      beforeEach(() => {
+        return knex.migrate.latest({
+          directory: ['test/integration/migrate/test'],
+        });
+      });
+
+      afterEach(() => {
+        return knex.migrate.rollback(
+          { directory: ['test/integration/migrate/test'] },
+          true
+        );
+      });
+
+      it('should only undo the last migration that was run if all migrations have run', function() {
+        return knex.migrate
+          .down({
+            directory: ['test/integration/migrate/test'],
+          })
+          .then(() => {
+            return knex('knex_migrations')
+              .select('*')
+              .then((data) => {
+                expect(data).to.have.length(1);
+                expect(path.basename(data[0].name)).to.equal(
+                  '20131019235242_migration_1.js'
+                );
+              });
+          });
+      });
+
+      it('should only undo the last migration that was run if there are other migrations that have not yet run', function() {
+        return knex.migrate
+          .down({
+            directory: ['test/integration/migrate/test'],
+          })
+          .then(() => {
+            return knex.migrate
+              .down({
+                directory: ['test/integration/migrate/test'],
+              })
+              .then(() => {
+                return knex('knex_migrations')
+                  .select('*')
+                  .then((data) => {
+                    expect(data).to.have.length(0);
+                  });
+              });
+          });
+      });
+
+      it('should not error if all migrations have already been undone', function() {
+        return knex.migrate
+          .rollback({ directory: ['test/integration/migrate/test'] }, true)
+          .then(() => {
+            return knex.migrate
+              .down({
+                directory: ['test/integration/migrate/test'],
+              })
+              .then((data) => {
+                expect(data).to.be.an('array');
+              });
+          });
+      });
+    });
+
     after(function() {
       rimraf.sync(path.join(__dirname, './migration'));
     });