task(libs/accounts): Port email sending code to libs

libs/accounts/email-sender/.eslintrc.json

@@ -0,0 +1,18 @@
+{
+  "extends": ["../../../.eslintrc.json"],
+  "ignorePatterns": ["!**/*"],
+  "overrides": [
+    {
+      "files": ["*.ts", "*.tsx", "*.js", "*.jsx"],
+      "rules": {}
+    },
+    {
+      "files": ["*.ts", "*.tsx"],
+      "rules": {}
+    },
+    {
+      "files": ["*.js", "*.jsx"],
+      "rules": {}
+    }
+  ]
+}

libs/accounts/email-sender/README.md

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+# accounts-email-sender
+
+This library was generated with [Nx](https://nx.dev).
+
+## Building
+
+Run `nx build accounts-email-senders` to build the library.
+
+## Running unit tests
+
+Run `nx test-unit accounts-email-senders` to execute the unit tests via [Jest](https://jestjs.io).

libs/accounts/email-sender/jest.config.ts

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+/* eslint-disable */
+export default {
+  displayName: 'accounts-email-sender',
+  preset: '../../../jest.preset.js',
+  testEnvironment: 'node',
+  transform: {
+    '^.+\\.[tj]s$': ['ts-jest', { tsconfig: '<rootDir>/tsconfig.spec.json' }],
+  },
+  moduleFileExtensions: ['ts', 'js', 'html'],
+  coverageDirectory: '../../../coverage/libs/accounts/email-sender',
+  reporters: [
+    'default',
+    [
+      'jest-junit',
+      {
+        outputDirectory: 'artifacts/tests/lib/accounts/email-sender',
+        outputName: 'accounts-email-sender-jest-unit-results.xml',
+      },
+    ],
+  ],
+};

libs/accounts/email-sender/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "@fxa/accounts/email-sender",
+  "version": "0.0.1",
+  "dependencies": {},
+  "type": "commonjs",
+  "main": "./index.cjs",
+  "types": "./index.d.ts",
+  "private": true
+}

libs/accounts/email-sender/project.json

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+{
+  "name": "accounts-email-sender",
+  "$schema": "../../../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "libs/accounts/email-sender/src",
+  "projectType": "library",
+  "tags": ["scope:shared:lib"],
+  "targets": {
+    "build": {
+      "executor": "@nx/esbuild:esbuild",
+      "outputs": ["{options.outputPath}"],
+      "options": {
+        "outputPath": "dist/libs/accounts/email-sender",
+        "main": "libs/accounts/email-sender/src/index.ts",
+        "tsConfig": "libs/accounts/email-sender/tsconfig.lib.json",
+        "assets": ["libs/accounts/email-sender/*.md"],
+        "format": ["cjs"],
+        "generatePackageJson": true
+      }
+    },
+    "test-unit": {
+      "executor": "@nx/jest:jest",
+      "outputs": ["{workspaceRoot}/coverage/{projectRoot}"],
+      "options": {
+        "jestConfig": "libs/accounts/email-sender/jest.config.ts",
+        "testPathPattern": ["^(?!.*\\.in\\.spec\\.ts$).*$"]
+      }
+    },
+    "test-integration": {
+      "executor": "@nx/jest:jest",
+      "outputs": ["{workspaceRoot}/coverage/{projectRoot}"],
+      "options": {
+        "jestConfig": "libs/accounts/email-sender/jest.config.ts",
+        "testPathPattern": ["\\.in\\.spec\\.ts$"]
+      }
+    }
+  }
+}

libs/accounts/email-sender/src/bounces.ts

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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { AppError } from '@fxa/accounts/errors';
+
+export type BouncesConfig = {
+  enabled: boolean;
+  hard: Record<number, number>;
+  soft: Record<number, number>;
+  complaint: Record<number, number>;
+  ignoreTemplates: string[];
+};
+
+export type Bounce = {
+  bounceType: number;
+  createdAt: number;
+};
+
+export type Tally = {
+  count: number;
+  latest: number;
+};
+
+export type BounceDb = {
+  emailBounces: {
+    findByEmail(email: string): Promise<Array<Bounce>>;
+  };
+};
+
+const BOUNCE_TYPE_HARD = 1;
+const BOUNCE_TYPE_SOFT = 2;
+const BOUNCE_TYPE_COMPLAINT = 3;
+
+export class Bounces {
+  private readonly bounceRules: Record<number, any>;
+
+  constructor(
+    private readonly config: BouncesConfig,
+    private readonly db: BounceDb
+  ) {
+    this.bounceRules = {
+      [BOUNCE_TYPE_HARD]: Object.freeze(config.hard || {}),
+      [BOUNCE_TYPE_SOFT]: Object.freeze(config.soft || {}),
+      [BOUNCE_TYPE_COMPLAINT]: Object.freeze(config.complaint || {}),
+    };
+  }
+
+  async check(email: string, template: string) {
+    if (this.config.enabled) {
+      return await this.checkBounces(email, template);
+    }
+  }
+
+  async checkBounces(email: string, template: string) {
+    if (this.config.ignoreTemplates.includes(template)) {
+      return;
+    }
+
+    const bounces = await this.db.emailBounces.findByEmail(email);
+    this.applyRules(bounces);
+  }
+
+  private applyRules(bounces: Array<Bounce>) {
+    const tallies: Record<number, any> = {
+      [BOUNCE_TYPE_HARD]: {
+        count: 0,
+        latest: 0,
+      },
+      [BOUNCE_TYPE_COMPLAINT]: {
+        count: 0,
+        latest: 0,
+      },
+      [BOUNCE_TYPE_SOFT]: {
+        count: 0,
+        latest: 0,
+      },
+    };
+    const now = Date.now();
+
+    bounces.forEach((bounce: Bounce) => {
+      const type = bounce.bounceType;
+      const ruleSet = this.bounceRules[type];
+      if (ruleSet) {
+        const tally = tallies[type];
+        const tier = ruleSet[tally.count];
+        if (!tally.latest) {
+          tally.latest = bounce.createdAt;
+        }
+        if (tier && bounce.createdAt > now - tier) {
+          if (type === BOUNCE_TYPE_HARD) {
+            throw AppError.emailBouncedHard(tally.latest);
+          }
+          if (type === BOUNCE_TYPE_COMPLAINT) {
+            throw AppError.emailComplaint(tally.latest);
+          }
+          if (type === BOUNCE_TYPE_SOFT) {
+            throw AppError.emailBouncedSoft(tally.latest);
+          }
+        }
+        tally.count++;
+      }
+    });
+    return tallies;
+  }
+}