React with TypeScript using tsyringe for dependency injection - reactjs

Question

I am currently having trouble with my React TypeScript project.
I created my project with npx create-react-app my-app --template typescript.
I recently added tsyringe for dependency injection and was trying to implement it for an apiService. After following the readme(https://github.com/microsoft/tsyringe#injecting-primitive-values-named-injection) for adding primitive values I have hit a block. I already add experimentalDecorators and emitDecoratorMetadata to my tsconfig.json file with no success.
The error actual error I am encountering is:
./src/ts/utils/NetworkService.ts 9:14
Module parse failed: Unexpected character '#' (9:14)
File was processed with these loaders:
* ./node_modules/#pmmmwh/react-refresh-webpack-plugin/loader/index.js
* ./node_modules/babel-loader/lib/index.js
You may need an additional loader to handle the result of these loaders.
|
| let NetworkService = (_dec = singleton(), _dec(_class = (_temp = class NetworkService {
> constructor(#inject('SpecialString')
| value) {
| this.str = void 0;
I am fairly sure this problem is caused by Babel, however I created this with npm create react-app --template typescript and do not seem to have access to the Babel configuration.
NetworkService.ts
#singleton()
export default class NetworkService
{
private str: string;
constructor(#inject('SpecialString') value: string) {
this.str = value;
}
}
Invocation method
bob()
{
const inst = container.resolve(NetworkService);
}
Registering Class in index.ts
container.register('SpecialString', {useValue: 'https://myme.test'});
#registry([
{ token: NetworkService, useClass: NetworkService },
])
class RegisterService{}

Answer 1

React-Scripts manages many of the configs related to the project. For many cases, this is fine and actually a nice feature. However, because React-Scripts uses Babel for it's development environment and does not expose the config.
You have to run npm run eject to expose the configurations.
Please note, this is a one-way operation and can not be undone.
Personally, I prefer more control with my configuration.
After this you can edit the webpack.config.js in the newly created config folder.
Find the section related to the babel-loader in the dev-environment and add 'babel-plugin-transform-typescript-metadata' to the plugins array.

Answer 2

Expanding on Jordan Schnur's reply, here are some more pitfalls I encountered when adding TSyringe to my CRA app:
Use import type with #inject
If you get this error "TS1272: A type referenced in a decorated signature must be imported with 'import type' or a namespace import when 'isolatedModules' and 'emitDecoratorMetadata' are enabled." replace import with import type for the offending imports. You will encounter this when working with #inject
E.g. replace import { IConfig } from "iconfig" with import type { IConfig } from "iconfig"
Fixing Jest
Your Jest tests will also break with TSyringe, especially when using #inject. I got the error "Jest encountered an unexpected token" with details constructor(#((0, _tsyringe.inject)("")) ("#" marked as the offending token). I took the following steps to fix that in CRA:
Add the line import "reflect-metadata"; to the top of the file src/setupTests.ts
In config/jest/babelTransform.js replace line 18 and following:
From
module.exports = babelJest.createTransformer({
presets: [
[
require.resolve('babel-preset-react-app'),
{
runtime: hasJsxRuntime ? 'automatic' : 'classic',
},
],
],
babelrc: false,
configFile: false,
});
to:
module.exports = babelJest.createTransformer({
presets: [
[
require.resolve('babel-preset-react-app'),
{
runtime: hasJsxRuntime ? 'automatic' : 'classic',
},
],
],
plugins: [
require.resolve('babel-plugin-transform-typescript-metadata')
],
babelrc: false,
configFile: false,
});

Answer 3

Instead of eject, you may use a lib that "overrides" some of your params.
I used craco : https://www.npmjs.com/package/#craco/craco

Answer 4

I've created an simpler DI library that doesn't need decorators or polyfill. Works with CRA like a charm and has cool React bindings
iti
import { useContainer } from "./_containers/main-app"
function Profile() {
const [auth, authErr] = useContainer().auth
if (authErr) return <div>failed to load</div>
if (!auth) return <div>loading...</div>
return <div>hello {auth.profile.name}!</div>
}