simple test for then and catch

test/unit/getSerie.js

+const expect = require('chai').expect;
+const getSerieMW = require('../../middleware/serie/getSerie');
+
+describe('getSerie ', () => {
+  it('should connect to database', (done) => {
+    const req = {
+      params: {
+        id: 10
+      }
+    };
+    const res = {
+      tpl: {
+        serie: {
+          name: 'asd'
+        }
+      }
+    };
+    const mockSerieModel = {
+      findById: (id) => ({
+        then: (then, error) => {
+          then({ name: 'asd' }, undefined);
+          error()
+        }
+      })
+    };
+    getSerieMW({ serieModel: mockSerieModel })(req, res, (err) => {
+      expect(res.tpl.serieId).to.eql(10);
+      expect(res.tpl.serie).to.have.property('name');
+      expect(res.tpl.serie.name).to.eql('asd');
+      done();
+    })
+  });
+});

test/unit/main.js

-const expect = require('chai').expect;
-const getSerieMW = require('../../middleware/serie/getSerie');
-
-describe('test ', () => {
-  it('main test', (done) => {
-    done();
-  });
-});