diff --git a/package.json b/package.json
index 5763fdc..6e7f289 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
     "start": "tsc && node dist/index.js || exit 1",
     "dev": "nodemon -e ts,yaml --exec \"npm run start\"",
     "loadDev": "node dist/test/loadDev.js",
-    "coverage": "nyc --reporter=html --reporter=tex mocha dist/**/**.spec.js"
+    "coverage": "tsc && nyc --reporter=html --reporter=text mocha dist/**/**.spec.js --timeout 5000"
   },
   "keywords": [],
   "author": "",
diff --git a/src/db.ts b/src/db.ts
index c1d1fbb..fb5d424 100644
--- a/src/db.ts
+++ b/src/db.ts
@@ -42,15 +42,18 @@ export default class db {
     });
     mongoose.connection.on('error', console.error.bind(console, 'connection error:'));
     mongoose.connection.on('disconnected', () => {  // reset state on disconnect
-      console.info('Database disconnected');
-      this.state.db = 0;
-      done();
+      if (process.env.NODE_ENV !== 'test') {  // Do not interfere with testing
+        console.info('Database disconnected');
+        this.state.db = 0;
+      }
     });
     process.on('SIGINT', () => {  // close connection when app is terminated
-      mongoose.connection.close(() => {
-        console.info('Mongoose default connection disconnected through app termination');
-        process.exit(0);
-      });
+      if (!this.state.db) {  // database still connected
+        mongoose.connection.close(() => {
+          console.info('Mongoose default connection disconnected through app termination');
+          process.exit(0);
+        });
+      }
     });
     mongoose.connection.once('open', () => {
       mongoose.set('useFindAndModify', false);
@@ -60,6 +63,14 @@ export default class db {
     });
   }
 
+  static disconnect (done) {
+    mongoose.connection.close(() => {
+      console.info(process.env.NODE_ENV === 'test' ? '' : `Disconnected from database`);
+      this.state.db = 0;
+      done();
+    });
+  }
+
   static getState () {
     return this.state;
   }
diff --git a/src/index.ts b/src/index.ts
index 55ca5ff..c007ca9 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -13,6 +13,7 @@ import db from './db';
 // TODO: add multiple samples at once
 // TODO: coverage
 // TODO: think about the display of deleted/new samples and validation in data and UI
+// TODO: improve error coverage
 
 // tell if server is running in debug or production environment
 console.info(process.env.NODE_ENV === 'production' ? '===== PRODUCTION =====' : process.env.NODE_ENV === 'test' ? '' :'===== DEVELOPMENT =====');
diff --git a/src/routes/material.spec.ts b/src/routes/material.spec.ts
index 344642d..ae8d305 100644
--- a/src/routes/material.spec.ts
+++ b/src/routes/material.spec.ts
@@ -12,6 +12,7 @@ describe('/material', () => {
   before(done => TestHelper.before(done));
   beforeEach(done => server = TestHelper.beforeEach(server, done));
   afterEach(done => TestHelper.afterEach(server, done));
+  after(done => TestHelper.after(done));
 
   describe('GET /materials', () => {
     it('returns all materials', done => {
@@ -146,7 +147,6 @@ describe('/material', () => {
             }
           });
         });
-        done();
       });
     });
     it('rejects requests from a write user', done => {
diff --git a/src/routes/measurement.spec.ts b/src/routes/measurement.spec.ts
index 6e58290..e1f36a4 100644
--- a/src/routes/measurement.spec.ts
+++ b/src/routes/measurement.spec.ts
@@ -5,14 +5,17 @@ import globals from '../globals';
 
 // TODO: restore measurements for m/a
 
+// TODO: coverage!!!
+
 
 describe('/measurement', () => {
   let server;
   before(done => TestHelper.before(done));
   beforeEach(done => server = TestHelper.beforeEach(server, done));
   afterEach(done => TestHelper.afterEach(server, done));
+  after(done => TestHelper.after(done));
 
-  describe('GET /mesurement/{id}', () => {
+  describe('GET /measurement/{id}', () => {
     it('returns the right measurement', done => {
       TestHelper.request(server, done, {
         method: 'get',
diff --git a/src/routes/measurement.ts b/src/routes/measurement.ts
index 78b7ec1..0d0f0f6 100644
--- a/src/routes/measurement.ts
+++ b/src/routes/measurement.ts
@@ -36,7 +36,7 @@ router.put('/measurement/' + IdValidate.parameter(), async (req, res, next) => {
   const data = await MeasurementModel.findById(req.params.id).lean().exec().catch(err => {next(err);}) as any;
   if (data instanceof Error) return;
   if (!data) {
-    res.status(404).json({status: 'Not found'});
+    return res.status(404).json({status: 'Not found'});
   }
 
   // add properties needed for sampleIdCheck
@@ -55,7 +55,6 @@ router.put('/measurement/' + IdValidate.parameter(), async (req, res, next) => {
   if (!await templateCheck(measurement, 'change', res, next)) return;
   await MeasurementModel.findByIdAndUpdate(req.params.id, measurement, {new: true}).lean().exec((err, data) => {
     if (err) return next(err);
-    console.log(data);
     res.json(MeasurementValidate.output(data));
   });
 });
@@ -66,12 +65,12 @@ router.delete('/measurement/' + IdValidate.parameter(), (req, res, next) => {
   MeasurementModel.findById(req.params.id).lean().exec(async (err, data) => {
     if (err) return next(err);
     if (!data) {
-      res.status(404).json({status: 'Not found'});
+      return res.status(404).json({status: 'Not found'});
     }
     if (!await sampleIdCheck(data, req, res, next)) return;
     await MeasurementModel.findByIdAndUpdate(req.params.id, {status:globals.status.deleted}).lean().exec(err => {
       if (err) return next(err);
-      res.json({status: 'OK'});
+      return res.json({status: 'OK'});
     });
   });
 });
@@ -89,7 +88,6 @@ router.post('/measurement/new', async (req, res, next) => {
   measurement.status = 0;
   await new MeasurementModel(measurement).save((err, data) => {
     if (err) return next(err);
-    console.log(data);
     res.json(MeasurementValidate.output(data.toObject()));
   });
 });
diff --git a/src/routes/root.spec.ts b/src/routes/root.spec.ts
index f8a803f..a5f8f8b 100644
--- a/src/routes/root.spec.ts
+++ b/src/routes/root.spec.ts
@@ -1,4 +1,5 @@
 import TestHelper from "../test/helper";
+import db from '../db';
 
 
 describe('/', () => {
@@ -6,6 +7,7 @@ describe('/', () => {
   before(done => TestHelper.before(done));
   beforeEach(done => server = TestHelper.beforeEach(server, done));
   afterEach(done => TestHelper.afterEach(server, done));
+  after(done => TestHelper.after(done));
 
   describe('GET /', () => {
     it('returns the root message', done => {
@@ -40,7 +42,15 @@ describe('/', () => {
       TestHelper.request(server, done, {
         method: 'get',
         url: '/authorized',
-        auth: {name: 'admin', pass: 'Abc123!!'},
+        auth: {basic: {name: 'admin', pass: 'Abc123!!'}},
+        httpStatus: 401
+      });
+    });
+    it('does not work with incorrect username', done => {
+      TestHelper.request(server, done, {
+        method: 'get',
+        url: '/authorized',
+        auth: {basic: {name: 'adminxx', pass: 'Abc123!!'}},
         httpStatus: 401
       });
     });
@@ -66,4 +76,32 @@ describe('/', () => {
       });
     });
   });
+
+  describe('An invalid JSON body', () => {
+    it('is rejected', done => {
+      TestHelper.request(server, done, {
+        method: 'post',
+        url: '/',
+        httpStatus: 400,
+        reqType: 'json',
+        req: '{"xxx"}',
+        res: {status: 'Invalid JSON body'}
+      });
+
+    });
+  });
+
+  describe('A not connected database', () => {
+    it('resolves to an 500 error', done => {
+      db.disconnect(() => {
+        TestHelper.request(server, done, {
+          method: 'get',
+          url: '/',
+          httpStatus: 500
+        });
+      });
+    });
+  });
+
+  // describe('API')  // TODO not in production
 });
\ No newline at end of file
diff --git a/src/routes/sample.spec.ts b/src/routes/sample.spec.ts
index f54f5b4..cfeeb7c 100644
--- a/src/routes/sample.spec.ts
+++ b/src/routes/sample.spec.ts
@@ -19,6 +19,7 @@ describe('/sample', () => {
   before(done => TestHelper.before(done));
   beforeEach(done => server = TestHelper.beforeEach(server, done));
   afterEach(done => TestHelper.afterEach(server, done));
+  after(done => TestHelper.after(done));
 
   describe('GET /samples', () => {
     it('returns all samples', done => {
@@ -197,7 +198,7 @@ describe('/sample', () => {
       });
     });
 
-    it('returns a deleted sample for a maintain/admin user', done => {  // TODO: make tests work
+    it('returns a deleted sample for a maintain/admin user', done => {
       TestHelper.request(server, done, {
         method: 'get',
         url: '/sample/400000000000000000000005',
diff --git a/src/routes/template.spec.ts b/src/routes/template.spec.ts
index 2ac09ae..54adfcb 100644
--- a/src/routes/template.spec.ts
+++ b/src/routes/template.spec.ts
@@ -13,6 +13,7 @@ describe('/template', () => {
   before(done => TestHelper.before(done));
   beforeEach(done => server = TestHelper.beforeEach(server, done));
   afterEach(done => TestHelper.afterEach(server, done));
+  after(done => TestHelper.after(done));
 
   describe('/template/condition', () => {
     describe('GET /template/conditions', () => {
diff --git a/src/routes/template.ts b/src/routes/template.ts
index f4054c1..849cf59 100644
--- a/src/routes/template.ts
+++ b/src/routes/template.ts
@@ -44,7 +44,7 @@ router.put('/template/:collection(measurement|condition)/' + IdValidate.paramete
   const templateData = await model(req).findById(req.params.id).lean().exec().catch(err => {next(err);}) as any;
   if (templateData instanceof Error) return;
   if (!templateData) {
-    res.status(404).json({status: 'Not found'});
+    return res.status(404).json({status: 'Not found'});
   }
 
   if (!_.isEqual(_.pick(templateData, _.keys(template)), template)) {  // data was changed
diff --git a/src/routes/user.spec.ts b/src/routes/user.spec.ts
index a7a2ddb..a0d67a5 100644
--- a/src/routes/user.spec.ts
+++ b/src/routes/user.spec.ts
@@ -9,6 +9,7 @@ describe('/user', () => {
   before(done => TestHelper.before(done));
   beforeEach(done => server = TestHelper.beforeEach(server, done));
   afterEach(done => TestHelper.afterEach(server, done));
+  after(done => TestHelper.after(done));
 
   describe('GET /users', () => {
     it('returns all users', done => {
diff --git a/src/test/helper.ts b/src/test/helper.ts
index c724d14..539eba3 100644
--- a/src/test/helper.ts
+++ b/src/test/helper.ts
@@ -39,6 +39,10 @@ export default class TestHelper {
     server.close(done);
   }
 
+  static after(done) {
+    db.disconnect(done);
+  }
+
   static request (server, done, options) {  // options in form: {method, url, auth: {key/basic: 'name' or 'key'/{name, pass}}, httpStatus, req, res}
     let st = supertest(server);
     if (options.hasOwnProperty('auth') && options.auth.hasOwnProperty('key')) {  // resolve API key
@@ -58,6 +62,9 @@ export default class TestHelper {
         st = st.delete(options.url)
         break;
     }
+    if (options.hasOwnProperty('reqType')) {  // request body
+      st = st.type(options.reqType);
+    }
     if (options.hasOwnProperty('req')) {  // request body
       st = st.send(options.req);
     }