Absolute path hell with TypeScript / NodeJS

[jimpouwels]

There's probably multiple questions on this already, but so far I've not been able to tackle this issue for my scenario.

Background:

Folder structure:

• src
  • Server.ts
  • App.ts
• test
  • test classes
• package.json
• tsconfig.json

package.json

{
  "name": "fallen",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "tsc",
    "test": "mocha --require ts-node/register --watch-extensions ts './test/**/*.ts' --recursive -r tsconfig-paths/register './test/**/*.ts'",
    "dev": "ts-node ./src/server.ts",
    "start": "nodemon ./dist/server.js",
    "prod": "npm run build && npm run start"
  },
  "author": "Jim Pouwels",
  "license": "",
  "dependencies": {
    "@types/chai-http": "^3.0.5",
    "@types/express": "^4.16.0",
    "@types/pg": "^7.4.11",
    "body-parser": "^1.18.3",
    "chai-http": "^4.2.0",
    "express": "^4.16.4",
    "nodemon": "^1.18.9",
    "pg": "^7.7.1",
    "pg-promise": "^8.5.4"
  },
  "devDependencies": {
    "@types/chai": "^4.1.7",
    "@types/mocha": "^5.2.5",
    "chai": "^4.2.0",
    "mocha": "^5.2.0",
    "ts-node": "^7.0.1",
    "tsconfig-paths": "^3.7.0",
    "typescript": "^3.2.2"
  }
}

tsconfig.json

{
    "compilerOptions": {
        "module": "commonjs",
        "moduleResolution": "node",
        "pretty": true,
        "sourceMap": true,
        "target": "es6",
        "outDir": "dist",
        "baseUrl": "./src",
        "resolveJsonModule": true,
        "esModuleInterop": true
    },
    "include": [
        "src/**/*.ts"
    ],
    "exclude": [
        "node_modules"
    ]
}

VSCode accepts this, and also compiling 'tsc' works as a charm, so far so good. Even running unit tests with 'npm test' works, although I think that got fixed by adding '-r tsconfig-paths/register './test/**/*.ts'' to tsconfig.json.

However, when running with 'npm run dev' it fails to load module 'App'.

Server.ts

import app from 'App';
const PORT = 8080;

var service = app.expressApp.listen(PORT, () => {
    console.log('Express server listening on port ' + PORT);
})

I've read/found that this is because NodeJS has no knowledge of these absolute paths, but how can this be fixed?

There's no way I'm going to use these dreadful relative paths everywhere ;)

Error:

npm run dev

> fallen@1.0.0 dev ~/fallen
> ts-node ./src/server.ts

Error: Cannot find module 'App'
    at Function.Module._resolveFilename (module.js:547:15)
    at Function.Module._resolveFilename (~/fallen/node_modules/module-alias/index.js:49:29)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (~/fallen/src/server.ts:2:1)
    at Module._compile (module.js:652:30)
    at Module.m._compile (~/fallen/node_modules/ts-node/src/index.ts:439:23)
    at Module._extensions..js (module.js:663:10)
    at Object.require.extensions.(anonymous function) [as .ts] (~/fallen/node_modules/ts-node/src/index.ts:442:12)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! fallen@1.0.0 dev: `ts-node ./src/server.ts`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the fallen@1.0.0 dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/jim/.npm/_logs/2019-01-05T09_27_41_657Z-debug.log```

[ignitenet-martynas]

This should help:
https://nodejs.org/api/modules.html#modules_loading_from_the_global_folders

Bascally, you'd do

NODE_PATH=./src ts-node ./src/server.ts

[jimpouwels]

@ignitenet-martynas Thanks! That did the trick!

I added it to the package.json:

"dev": "NODE_PATH=./src ts-node ./src/server.ts",

[luchotess]

I fixed a similar issue with this but npm run prod is still throwing the same error. Any thoughts?

[igor-a-yastrebov]

key aspect why it worked out in test is: "tsconfig-paths": "^3.7.0" and "-r tsconfig-paths/register"
if you want it works in rest of the code, put following as a very first execution line: require('tsconfig-paths/register');

[guidiamond]

I fixed a similar issue with this but npm run prod is still throwing the same error. Any thoughts?
Supposing your outDir is /build/:
Just do "prod": "NODE_PATH=./build node ./build/index.js" on your package.json

[revskill10]

@ignitenet-martynas Thanks! That did the trick!

I added it to the package.json:

"dev": "NODE_PATH=./src ts-node ./src/server.ts",

You're a genius . Thanks.