update unit test

__tests__/gitlab.unit.test.js

-const gitlab = require('../routes/gitlab')
+const gitlab = require('../functions/gitlab')
 //const axios = require('axios')
 //jest.mock('axios')
 

__tests__/method.unit.test.js

-const methods = require('../routes/methods')
+const methods = require('../functions/methods')
 
 describe("DB methohds test", () => {
 
-    it('returns a user from DB by email', done => {
-        methods.getUserByEmail('litehon958@whipjoy.com', function(resp, err){
-            try {
-                expect(resp).not.toBeNull()
-                expect(err).toBeNull()
-                done()
-            } catch (error) {
-                done(error)
-            }
-        })    
-    })
-
-    it("returns a user from DB by ID", done => {
-        methods.getUserById(10, function(resp, err){
-            try {
-                expect(resp).not.toBeNull()
-                expect(err).toBeNull()
-                done()
-            } catch (error) {
-                done(error)
-            }
-        })    
-    })
-
-    it("checks user email", done => {
-        methods.checkUserEmail("test@email.de", function(err, resp){
-            try {
-                expect(resp).not.toBeNull()
-                expect(err).toBeNull()
-                done()
-            } catch (error) {
-                done(error)
-            }
-        })
-    })
-
-    it("returns a user by token", done => { 
-        methods.checkUserEmail("1abc0qwerty", function(err, resp){ // token = any alphanumeric
-            try {
-                expect(resp).not.toBeNull()
-                expect(err).toBeNull()
-                done()
-            } catch (error) {
-                done(error)
-            }
-        })
+    it("returns a user from DB by email", async() => {
+        const user = await methods.getUserByEmail('litehon958@whipjoy.com')
+        expect(user).not.toBeNull()
     })
+    it("returns a null user", async() => {
+        const user = await methods.getUserByEmail('jondoe@nowhere.com') // a non-exist user
+        expect(user).toBeNull()
+    })
+
+    it("returns a user's email", async() => {
+        const email = await methods.getUserEmailById(1)
+        expect(email).not.toBeNull()
+    })
+    it("returns null instead of a user's email", async() => {
+        const email = await methods.getUserEmailById(1005) // no user has this ID
+        expect(email).toBeNull()
+    })
+
+    it("returns null from DB by token", async() => {
+        const user = await methods.getUserByToken('12345678') // unvalid token
+        expect(user).toBeNull() // for valid token = expect(user).not.toBeNull()
+    })
+
+    it("returns a user's verification token, if any", async() => {
+        const token = await methods.getVerificationTokenByUserId(1)
+        expect(token).toBeNull()
+    })
+
+    it("returns a user's ID, if any", async() => {
+        const token = await methods.getUserIdByVerificationToken('12345678') // unvalid token
+        expect(token).toBeNull() // for valid token = expect(user).not.toBeNull()
+    })
+
+    it("returns a user's GitLab_ID, if any", async() => {
+        const id = await methods.getGitlabId(1)
+        expect(id).not.toBeNull()
+    })
+
+    it("checks user email", async() => {
+        const user = await methods.checkUserEmail('litehon958@whipjoy.com')
+        expect(user).not.toBeNull()
+    })
+    it("checks user email and return null", async() => {
+        const user = await methods.checkUserEmail('jondoe@nowhere.com') // a non-exist user
+        expect(user).toBeNull()
+    })
+
 })