refactor(core): Replace typedi with our custom DI system (no-changelo…

…g) (#12389)

Co-authored-by: Iván Ovejero <ivov.src@gmail.com>

package.json

@@ -84,7 +84,6 @@
       "ws": ">=8.17.1"
     },
     "patchedDependencies": {
-      "typedi@0.10.0": "patches/typedi@0.10.0.patch",
       "pkce-challenge@3.0.0": "patches/pkce-challenge@3.0.0.patch",
       "pyodide@0.23.4": "patches/pyodide@0.23.4.patch",
       "@types/express-serve-static-core@4.17.43": "patches/@types__express-serve-static-core@4.17.43.patch",

packages/@n8n/config/package.json

@@ -21,7 +21,7 @@
     "dist/**/*"
   ],
   "dependencies": {
-    "reflect-metadata": "0.2.2",
-    "typedi": "catalog:"
+    "@n8n/di": "workspace:*",
+    "reflect-metadata": "catalog:"
   }
 }

packages/@n8n/config/src/decorators.ts

@@ -1,6 +1,6 @@
 import 'reflect-metadata';
+import { Container, Service } from '@n8n/di';
 import { readFileSync } from 'fs';
-import { Container, Service } from 'typedi';
 
 // eslint-disable-next-line @typescript-eslint/ban-types
 type Class = Function;
@@ -35,7 +35,7 @@ export const Config: ClassDecorator = (ConfigClass: Class) => {
 
 		for (const [key, { type, envName }] of classMetadata) {
 			if (typeof type === 'function' && globalMetadata.has(type)) {
-				config[key] = Container.get(type);
+				config[key] = Container.get(type as Constructable);
 			} else if (envName) {
 				const value = readEnv(envName);
 				if (value === undefined) continue;

packages/@n8n/config/test/config.test.ts

@@ -1,6 +1,6 @@
+import { Container } from '@n8n/di';
 import fs from 'fs';
 import { mock } from 'jest-mock-extended';
-import { Container } from 'typedi';
 
 import { GlobalConfig } from '../src/index';
 

packages/@n8n/config/test/decorators.test.ts

@@ -1,4 +1,4 @@
-import { Container } from 'typedi';
+import { Container } from '@n8n/di';
 
 import { Config, Env } from '../src/decorators';
 

packages/@n8n/config/tsconfig.json

@@ -9,5 +9,6 @@
 		"baseUrl": "src",
 		"tsBuildInfoFile": "dist/typecheck.tsbuildinfo"
 	},
-	"include": ["src/**/*.ts", "test/**/*.ts"]
+	"include": ["src/**/*.ts", "test/**/*.ts"],
+	"references": [{ "path": "../di/tsconfig.build.json" }]
 }

packages/@n8n/di/.eslintrc.js

@@ -0,0 +1,7 @@
+const sharedOptions = require('@n8n_io/eslint-config/shared');
+
+/** @type {import('@types/eslint').ESLint.ConfigData} */
+module.exports = {
+	extends: ['@n8n_io/eslint-config/base'],
+	...sharedOptions(__dirname),
+};

packages/@n8n/di/README.md

@@ -0,0 +1,52 @@
+## @n8n/di
+
+`@n8n/di` is a dependency injection (DI) container library, based on [`typedi`](https://github.com/typestack/typedi).
+
+n8n no longer uses `typedi` because:
+
+- `typedi` is no longer officially maintained
+- Need for future-proofing, e.g. stage-3 decorators
+- Small enough that it is worth the maintenance burden
+- Easier to customize, e.g. to simplify unit tests
+
+### Usage
+
+```typescript
+// from https://github.com/typestack/typedi/blob/develop/README.md
+import { Container, Service } from 'typedi';
+
+@Service()
+class ExampleInjectedService {
+  printMessage() {
+    console.log('I am alive!');
+  }
+}
+
+@Service()
+class ExampleService {
+  constructor(
+    // because we annotated ExampleInjectedService with the @Service()
+    // decorator TypeDI will automatically inject an instance of
+    // ExampleInjectedService here when the ExampleService class is requested
+    // from TypeDI.
+    public injectedService: ExampleInjectedService
+  ) {}
+}
+
+const serviceInstance = Container.get(ExampleService);
+// we request an instance of ExampleService from TypeDI
+
+serviceInstance.injectedService.printMessage();
+// logs "I am alive!" to the console
+```
+
+Requires enabling these flags in `tsconfig.json`:
+
+```json
+{
+  "compilerOptions": {
+    "experimentalDecorators": true,
+    "emitDecoratorMetadata": true
+  }
+}
+```

packages/@n8n/di/jest.config.js

@@ -0,0 +1,2 @@
+/** @type {import('jest').Config} */
+module.exports = require('../../../jest.config');

packages/@n8n/di/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "@n8n/di",
+  "version": "0.1.0",
+  "scripts": {
+    "clean": "rimraf dist .turbo",
+    "dev": "pnpm watch",
+    "typecheck": "tsc --noEmit",
+    "build": "tsc -p tsconfig.build.json",
+    "format": "biome format --write .",
+    "format:check": "biome ci .",
+    "lint": "eslint .",
+    "lintfix": "eslint . --fix",
+    "watch": "tsc -p tsconfig.build.json --watch",
+    "test": "jest",
+    "test:dev": "jest --watch"
+  },
+  "main": "dist/di.js",
+  "module": "src/di.ts",
+  "types": "dist/di.d.ts",
+  "files": [
+    "dist/**/*"
+  ],
+  "dependencies": {
+    "reflect-metadata": "catalog:"
+  }
+}