feat: add basic nats rpc

.env.example

@@ -1,4 +1,6 @@
 PORT=3000
 GATEWAY_PORT=3052
 GATEWAY_SUBGRAPHS='[{"name": "api", "url": "http://localhost:3000/graphql"}]'
+
+NATS_URL=nats://localhost:4222
 SAMPLE_DATABASE_URL=postgres://postgres:postgres@localhost:5432/postgres?schema=public

apps/api/src/app/app.module.ts

@@ -9,6 +9,7 @@ import {
     ApolloFederationDriver,
     ApolloFederationDriverConfig,
 } from '@nestjs/apollo'
+import { NatsModule } from 'core/nats'
 
 @Module({
     imports: [
@@ -30,6 +31,9 @@ import {
                 maxQueryExecutionTime: 5000,
             },
         }),
+        NatsModule.forRoot({
+            servers: env.get('NATS_URL').required().asString(),
+        }),
     ],
     controllers: [],
     providers: [],

libs/core/common/.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/core/common/README.md

@@ -0,0 +1,11 @@
+# common
+
+This library was generated with [Nx](https://nx.dev).
+
+## Building
+
+Run `nx build common` to build the library.
+
+## Running unit tests
+
+Run `nx test common` to execute the unit tests via [Jest](https://jestjs.io).

libs/core/common/jest.config.ts

@@ -0,0 +1,14 @@
+/* eslint-disable */
+export default {
+    displayName: 'common',
+    preset: '../../../jest.preset.js',
+    testEnvironment: 'node',
+    transform: {
+        '^.+\\.[tj]s$': [
+            'ts-jest',
+            { tsconfig: '<rootDir>/tsconfig.spec.json' },
+        ],
+    },
+    moduleFileExtensions: ['ts', 'js', 'html'],
+    coverageDirectory: '../../../coverage/libs/core/common',
+}

libs/core/common/project.json

@@ -0,0 +1,30 @@
+{
+  "name": "common",
+  "$schema": "../../../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "libs/core/common/src",
+  "projectType": "library",
+  "targets": {
+    "lint": {
+      "executor": "@nx/linter:eslint",
+      "outputs": ["{options.outputFile}"],
+      "options": {
+        "lintFilePatterns": ["libs/core/common/**/*.ts"]
+      }
+    },
+    "test": {
+      "executor": "@nx/jest:jest",
+      "outputs": ["{workspaceRoot}/coverage/{projectRoot}"],
+      "options": {
+        "jestConfig": "libs/core/common/jest.config.ts",
+        "passWithNoTests": true
+      },
+      "configurations": {
+        "ci": {
+          "ci": true,
+          "codeCoverage": true
+        }
+      }
+    }
+  },
+  "tags": []
+}

libs/core/common/src/index.ts

@@ -0,0 +1,2 @@
+export * from './lib/errors/common-errors.enum'
+export * from './lib/errors/common.error'

libs/core/common/src/lib/errors/common-errors.enum.ts

@@ -0,0 +1,21 @@
+export enum CommonErrorsEnum {
+    Error = 'ERROR-000',
+    NotFound = 'ERROR-001',
+    Forbidden = 'ERROR-002',
+    UnexpectedError = 'ERROR-003',
+    ValidationError = 'ERROR-004',
+    UniqueError = 'ERROR-005',
+    RequestError = 'ERROR-006',
+    UnauthorizedError = 'ERROR-007',
+}
+
+export const COMMON_ERROR_TITLES = {
+    [CommonErrorsEnum.Error]: 'Error',
+    [CommonErrorsEnum.NotFound]: 'Not found',
+    [CommonErrorsEnum.Forbidden]: 'Forbidden',
+    [CommonErrorsEnum.UnexpectedError]: 'Unexpected error',
+    [CommonErrorsEnum.ValidationError]: 'Validation error',
+    [CommonErrorsEnum.UniqueError]: 'Unique error',
+    [CommonErrorsEnum.RequestError]: 'Request error',
+    [CommonErrorsEnum.UnauthorizedError]: 'Unauthorized',
+}

libs/core/common/src/lib/errors/common.error.ts

@@ -0,0 +1,28 @@
+import { COMMON_ERROR_TITLES, CommonErrorsEnum } from './common-errors.enum'
+
+export class CommonError<
+    T extends string = CommonErrorsEnum,
+    M = Record<string, string>,
+> extends Error {
+    code: T
+    metadata?: M
+
+    constructor(
+        code: T,
+        message?: { [code: string]: string } | string,
+        metadata?: M,
+    ) {
+        super(
+            message === undefined
+                ? COMMON_ERROR_TITLES[
+                      (code as string) ||
+                          COMMON_ERROR_TITLES[CommonErrorsEnum.Error]
+                  ]
+                : typeof message === 'string'
+                ? message
+                : message[code],
+        )
+        this.code = code
+        this.metadata = metadata
+    }
+}

libs/core/common/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "module": "commonjs"
+  },
+  "files": [],
+  "include": [],
+  "references": [
+    {
+      "path": "./tsconfig.lib.json"
+    },
+    {
+      "path": "./tsconfig.spec.json"
+    }
+  ]
+}

libs/core/common/tsconfig.lib.json

@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../../../dist/out-tsc",
+    "declaration": true,
+    "types": ["node"],
+    "target": "es6"
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": ["jest.config.ts", "src/**/*.spec.ts", "src/**/*.test.ts"]
+}

libs/core/common/tsconfig.spec.json

@@ -0,0 +1,14 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../../../dist/out-tsc",
+    "module": "commonjs",
+    "types": ["jest", "node"]
+  },
+  "include": [
+    "jest.config.ts",
+    "src/**/*.test.ts",
+    "src/**/*.spec.ts",
+    "src/**/*.d.ts"
+  ]
+}

libs/core/nats/.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/core/nats/README.md

@@ -0,0 +1,11 @@
+# nats
+
+This library was generated with [Nx](https://nx.dev).
+
+## Building
+
+Run `nx build nats` to build the library.
+
+## Running unit tests
+
+Run `nx test nats` to execute the unit tests via [Jest](https://jestjs.io).

libs/core/nats/jest.config.ts

@@ -0,0 +1,14 @@
+/* eslint-disable */
+export default {
+    displayName: 'nats',
+    preset: '../../../jest.preset.js',
+    testEnvironment: 'node',
+    transform: {
+        '^.+\\.[tj]s$': [
+            'ts-jest',
+            { tsconfig: '<rootDir>/tsconfig.spec.json' },
+        ],
+    },
+    moduleFileExtensions: ['ts', 'js', 'html'],
+    coverageDirectory: '../../../coverage/libs/core/nats',
+}

libs/core/nats/project.json

@@ -0,0 +1,30 @@
+{
+  "name": "nats",
+  "$schema": "../../../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "libs/core/nats/src",
+  "projectType": "library",
+  "targets": {
+    "lint": {
+      "executor": "@nx/linter:eslint",
+      "outputs": ["{options.outputFile}"],
+      "options": {
+        "lintFilePatterns": ["libs/core/nats/**/*.ts"]
+      }
+    },
+    "test": {
+      "executor": "@nx/jest:jest",
+      "outputs": ["{workspaceRoot}/coverage/{projectRoot}"],
+      "options": {
+        "jestConfig": "libs/core/nats/jest.config.ts",
+        "passWithNoTests": true
+      },
+      "configurations": {
+        "ci": {
+          "ci": true,
+          "codeCoverage": true
+        }
+      }
+    }
+  },
+  "tags": []
+}

libs/core/nats/src/index.ts

@@ -0,0 +1,2 @@
+export * from './lib/nats-configs/nats-module.config'
+export * from './lib/nats.module'

libs/core/nats/src/lib/nats-configs/nats-module.config.ts

@@ -0,0 +1,32 @@
+import { ConfigurableModuleBuilder } from '@nestjs/common'
+import { merge } from 'lodash'
+import { ConnectionOptions } from 'nats'
+
+export interface NatsConfig extends ConnectionOptions {
+    temp?: false
+}
+
+export const DEFAULT_NATS_CONFIG: Pick<NatsConfig, 'temp'> = {
+    temp: false,
+}
+
+export function patchNatsConfig(
+    config: Pick<typeof NATS_OPTIONS_TYPE, keyof typeof DEFAULT_NATS_CONFIG>,
+) {
+    if (config) {
+        Object.assign(
+            config,
+            merge(DEFAULT_NATS_CONFIG, config),
+        ) as typeof NATS_OPTIONS_TYPE
+    }
+    return config
+}
+
+export const {
+    ConfigurableModuleClass: NatsConfigurableModuleClass,
+    MODULE_OPTIONS_TOKEN: NATS_CONFIG,
+    ASYNC_OPTIONS_TYPE: NATS_ASYNC_OPTIONS_TYPE,
+    OPTIONS_TYPE: NATS_OPTIONS_TYPE,
+} = new ConfigurableModuleBuilder<NatsConfig, 'forRoot'>({
+    optionsInjectionToken: `NATS_CONFIG`,
+}).build()

libs/core/nats/src/lib/nats-errors/nats-errors.enum.ts

@@ -0,0 +1,9 @@
+export enum NatsErrorsEnum {
+    Timeout = 'NATS-000',
+    NoResponders = 'NATS-001',
+}
+
+export const NATS_ERROR_TITLES = {
+    [NatsErrorsEnum.Timeout]: `Someone is listening but didn't respond`,
+    [NatsErrorsEnum.NoResponders]: `No one is listening to this request`,
+}

libs/core/nats/src/lib/nats-indicators/nats-connection-health.indicator.ts

@@ -0,0 +1,35 @@
+import { Injectable } from '@nestjs/common'
+import { HealthIndicator, HealthIndicatorResult } from 'core/health-checks'
+import { NatsConnectionService } from '../nats-services/nats-connection.service'
+
+@Injectable()
+export class NatsConnectionHealthIndicator implements HealthIndicator {
+    name = 'nats'
+
+    constructor(private readonly natsConnection: NatsConnectionService) {}
+
+    async isHealthy(): Promise<HealthIndicatorResult> {
+        try {
+            const status = this.natsConnection.status()
+
+            if (status.connected) {
+                return {
+                    name: this.name,
+                    status: 'up',
+                }
+            }
+
+            return {
+                name: this.name,
+                status: 'down',
+                error: status.error,
+            }
+        } catch (error) {
+            return {
+                name: this.name,
+                status: 'down',
+                error: error.message,
+            }
+        }
+    }
+}

libs/core/nats/src/lib/nats-interfaces/nats.interfaces.ts

@@ -0,0 +1,14 @@
+import { MsgHdrs, RequestOptions as NatsRequestOptions } from 'nats'
+
+export interface NatsResponse<T> {
+    subject: string
+    data?: T
+    headers?: MsgHdrs
+}
+
+export interface RequestOptions
+    extends Omit<NatsRequestOptions, 'headers' | 'timeout'> {
+    timeout?: number
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    headers: Record<string, string>
+}