Add test files

mocks/members.yaml

@@ -0,0 +1,4 @@
+admin:
+  - A
+members:
+  - B

package.json

@@ -16,8 +16,15 @@
     "typescript": "^3.5.3"
   },
   "devDependencies": {
+    "@types/jest": "^24.0.17",
     "@types/js-yaml": "^3.12.1",
     "@types/node": "^12.7.1",
+    "jest": "^24.8.0",
+    "ts-jest": "^24.0.2",
     "ts-node": "^8.3.0"
+  },
+  "jest": {
+    "preset": "ts-jest",
+    "testEnvironment": "node"
   }
 }

src/members-service.test.ts

@@ -0,0 +1,31 @@
+import { MembersService } from './members-service'
+
+describe('MembersService', () => {
+  let s: MembersService
+
+  beforeEach(() => {
+    s = new MembersService('mocks/members.yaml')
+  })
+
+  test('load file', () => {
+    expect(s.hasMember('B')).toBeTruthy()
+    expect(s.hasAdmin('A')).toBeTruthy()
+  })
+
+  test('getMembersToAdd', () => {
+    // since current members are empty
+    // B should be added as a new member
+    const currentMembers: string[] = []
+    expect(s.getMembersToAdd(currentMembers)).toStrictEqual(['B'])
+
+    currentMembers.push('B')
+    expect(s.getMembersToAdd(currentMembers)).toStrictEqual([])
+  })
+
+  test('getMembersToDelete', () => {
+    // C does not exist in the file;
+    // so C must be removed
+    const currentMembers = ['B', 'C']
+    expect(s.getMembersToDelete(currentMembers)).toStrictEqual(['C'])
+  })
+})

src/members-service.ts

@@ -32,7 +32,7 @@ export class MembersService {
     this.data.admin.add(member)
   }
 
-  hadAdmin(member: string): boolean {
+  hasAdmin(member: string): boolean {
     return this.data.admin.has(member)
   }