Hello everyone, I have a problem and I can't solve it. I want to implement path aliases in typescript. when i run:

pulumi up -y -s dev

my error

TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received an instance of Array

this is my

tsconfig.ts

{
  "compilerOptions": {
    "baseUrl": "./src",
    "paths": {
      "@application/*": [
        "application/*"
      ],
      "@config/*": [
        "config/*"
      ],
      "@domain/*": [
        "domain/*"
      ],
      "@api-route": [
        "api-route.ts"
      ],
      "@interfaces/*": [
        "interfaces/*"
      ]
    },
    "strict": true,
    "outDir": "bin",
    "target": "ESNEXT",
    "lib": [
      "ESNEXT"
    ],
    "module": "commonjs",
    "moduleResolution": "node",
    "sourceMap": true,
    "experimentalDecorators": true,
    "pretty": true,
    "noFallthroughCasesInSwitch": true,
    "noImplicitReturns": true,
    "esModuleInterop": true,
    "emitDecoratorMetadata": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "typeRoots": [
      "./node_modules/@types"
    ],
    "types": [
      "@types/node",
      "node"
    ]
  },
  "files": [
    "src/handler.ts"
  ],
  "include": [
    "src/**/*.ts"
  ],
  "exclude": [
    "node_modules"
  ]
}

my package.json

{
  "name": "api-notifications",
  "scripts": {
    "lint": "tslint -p tsconfig.json -c tslint.json",
    "prettify": "prettier . --write"
  },
  "main": "src/handler.ts",
  "devDependencies": {
    "@types/aws-sdk": "^2.7.0",
    "@types/dotenv": "^8.2.0",
    "@types/node": "^10.17.60",
    "typescript": "^4.2.4",
    "tslint": "^6.1.3",
    "tslint-config-airbnb": "^5.11.2"
  },
  "_moduleAliases": {
    "@application": [
      "bin/application"
    ],
    "@config": [
      "bin/config"
    ],
    "@domain": [
      "bin/domain"
    ],
    "@interfaces": [
      "bin/interfaces"
    ]
  },
  "dependencies": {
    "@pulumi/aws": "^4.0.0",
    "@pulumi/awsx": "^0.30.0",
    "@pulumi/pulumi": "^3.0.0",
    "@types/aws-lambda": "^8.10.76",
    "axios": "^0.21.1",
    "dotenv": "^9.0.2",
    "module-alias": "^2.2.2"
  }
}

Any idea or example to add the path aliases? for example: instead of this

import { CustomEventService } from "../../../application/services/custom-event/custom-event.service";

use this:

import { CustomEventService } from "@application/services/custom-event/custom-event.service";

in my

./src/handler.ts

I add

import "module-alias/register";

This is of interest to me too. I tried this, and I got a different error (Cannot find module '@mypath'), though it works in VSCode. I tried turning off the built-in typescript (Pulumi.yaml, runtime options typescript: false) and compiling myself, but no change.

my solution is:

"_moduleAliases": {
    "@application": "src/application",
    "@config": "src/config",
    "@domain": "src/domain",
    "@interfaces": "src/interfaces",
    "@api-route": "src/api-route"
  },

Does that require the module-alias module? Instead of the built-in path aliases?

I implemented it using the

"module-alias": "^2.2.2"

Good stuff. I moved the "path" section out of "compilerOptions" to the top level, renamed it to "_moduleAliases", removed the arrays (leaving just the paths), and added "module-alias/register" to my .mocharc.json require property. No joy 😞 "Cannot find module" errors...

@little-cartoon-10569 steps to follow:

npm i --save module-alias

in the

tsconfig.json

you define your paths: In my case

"compilerOptions": {
    "baseUrl": "./src",
    "paths": {
      "@application/*": ["application/*"],
      "@config/*": ["config/*"],
      "@domain/*": ["domain/*"],
      "@api-route": ["api-route.ts"],
      "@interfaces/*": ["interfaces/*"]
    },

in the

package.json

you define the

_moduleAliases

in my case

"_moduleAliases": {
    "@application": "src/application",
    "@config": "src/config",
    "@domain": "src/domain",
    "@interfaces": "src/interfaces",
    "@api-route": "src/api-route"
  },

now in the

index.ts

(in my case is

handler.ts

) you add

import "module-alias/register";

Hmm, I did that, still complained...

the baseURL is usually at the level of tsconfig.ts

my-project
    -- src
        -- index.ts
        -- folder1
        -- folder2
        ...
    -- tsconfig.ts
    ...

I see that your tsconfig.ts refers to ./src, but in your folder structure, that would be ../src...?

I have a

entry.ts

file which my package.json points to. it has

const path = require('path')
const tsConfig = require(__dirname + '/../../../tsconfig.base.json')
const tsConfigPaths = require('tsconfig-paths')
const args = {
    baseUrl: path.resolve(__dirname + '/../../..'),
    paths: tsConfig.compilerOptions.paths,
}
tsConfigPaths.register(args)

module.exports = require('./index')

I have a roll-my-own monorepo. Might look into NX. Though I see all those `require()`s and think.. esnext, es2020, ...

index.ts and down is all esmodules