メールアドレスの検証

Author: takecchi

jest.config.js

@@ -3,5 +3,8 @@ module.exports = {
   preset: 'ts-jest',
   testEnvironment: 'node',
   testMatch: ['**/test/**/*.ts', '**/test/**/?(*.)+(spec|test).ts'],
-  testPathIgnorePatterns: ['/node_modules/', '/dist/']
+  testPathIgnorePatterns: ['/node_modules/', '/dist/'],
+  moduleNameMapper: {
+    '^@/(.*)$': '<rootDir>/src/$1',
+  },
 };

package-lock.json

@@ -31,5 +31,9 @@
   "volta": {
     "node": "18.18.0",
     "npm": "10.2.0"
+  },
+  "dependencies": {
+    "@types/validator": "^13.9.0",
+    "validator": "^13.9.0"
   }
 }

package.json

@@ -0,0 +1,9 @@
+import isEmail from 'validator/lib/isEmail';
+
+export default function isValidEmail(mail: string) {
+  // 150文字制限
+  if (mail.length > 150) {
+    return false;
+  }
+  return isEmail(mail);
+}

src/index.ts

@@ -0,0 +1,23 @@
+import isValidEmail from '@/util/isValidEmail';
+
+describe('isValidEmail', () => {
+  it('150文字以下', () => {
+    expect(isValidEmail('cuculus@example.com')).toBe(true);
+  });
+
+  it('150文字以上', () => {
+    let prefix = '';
+    for (let i = 0; i < 150; i++) {
+      prefix += 'A';
+    }
+    expect(isValidEmail(`@example.com`)).toBe(false);
+  });
+
+  it('エイリアスが使用可能', () => {
+    expect(isValidEmail(`cuculus+test@example.com`)).toBe(true);
+  });
+
+  it('メールアドレスではない', () => {
+    expect(isValidEmail(`example.com`)).toBe(false);
+  });
+});

src/util/isValidEmail.ts

@@ -14,7 +14,13 @@
     "skipLibCheck": true,
     "forceConsistentCasingInFileNames": true,
     "esModuleInterop": true,
-    "outDir": "./dist"
+    "outDir": "./dist",
+    "paths": {
+      "@/*": [
+        "./src/*"
+      ]
+    }
   },
-  "exclude": ["node_modules", "test"]
+  "exclude": ["node_modules", "test"],
+
 }