Add unit tests for role-based access control

backend/jest.config.js

@@ -1,18 +1,12 @@
 export default {
   testEnvironment: 'node',
-  transform: {
-    '^.+\\.js$': 'babel-jest'
-  },
   testMatch: [
-    '**/tests/**/*.test.js',
-    '**/__tests__/**/*.js'
+    '**/tests/**/*.test.js'
   ],
-  moduleNameMapper: {
-    '^src/(.*)$': '<rootDir>/src/$1',
-    '^backend/(.*)$': '<rootDir>/$1'
-  },
-  transformIgnorePatterns: [
-    '/node_modules/',
-    '/backend/src/__tests__/'
-  ]
+  collectCoverageFrom: [
+    'src/**/*.js',
+    '!src/__tests__/**/*.js'
+  ],
+  coverageDirectory: 'coverage',
+  verbose: true
 };