how to run a custom compiler (programmatically, not from commandline)

[robbiemu]

branch currently with this issue

I am trying to use a worker_thread like so:

worker.js

const path = require('path');
const { workerData } = require('worker_threads');

require('ts-node').register(workerData.registerOptions);
require('tsconfig-paths').register();
require(path.resolve(__dirname, workerData.path));

worker.ts

import { parentPort, workerData } from 'worker_threads'

import { getBlockAtDifficulty } from './utilities'

const { block, difficulty, index, step } = workerData

parentPort!.postMessage(getBlockAtDifficulty(block, difficulty, index, step))

parent.ts

/**
 * spawns threads to resolve hash at difficulty, publishing result in 
 * MultiService
 * @param block Block to resolve hash of
 * @param difficulty Difficulty of hash to resolve
 * @returns uuid of multiservice to subscribe to
 * usage:
 * const multiService = new MultiService()
 * const task = getBlockAtDifficultyMultiThreaded(myBlock, someDifficulty)
 * multiService.resolve$
 *   .pipe(first(resolution => resolution.hasOwnProperty(task)))
 *   .subscribe(resolution => onSuccess(resolution[task]))
 */
export function getBlockAtDifficultyMultiThreaded(block: Partial<Block>, difficulty: number): UUID {
  const uuid = Hash.uuid() // our task identifier
  const workers: Array<Worker> = []
  const threads = os.cpus()
  const registerOptions = getRegisterOptions()

  threads.forEach((_, index) => {
    const args = { block, difficulty, index, step: threads.length }
    const worker: Worker = new Worker('./worker.js', {
      workerData: {
        path: 'src/blockchain/get-block-at-difficulty.worker.ts',
        args,
        registerOptions
      }
    })

    workers.push(worker)
    worker.on('message', (result: Block) => {
      MultiService.resolve(new Promise(res => res(result)), uuid)
      workers.forEach(w => w.terminate())
    })
  })
  return uuid
}

function getRegisterOptions() {
  const registerOptions = require('../../tsconfig.json')
  registerOptions.files = true

  return registerOptions
}

I've almost got it working now! but, my project makes use of a custom transformer ts-transformer-keys.

I installed ttypescript compiler to process this transformer, following the instructions on the project page for ts-transformer-keys. I also go it working with ts-jest in the same fashion.

To get it working in the worker thread, I need to specify the custom compiler ttypescript. How do I do that?

my tsconfig looks like this:

{
  "compilerOptions": { 
    "outDir": "dist/bundle",
    "baseUrl": "./src",
    "paths": {
      "@blockchain/*": [ "blockchain/*" ],
      "@hyperledger/*": [ "hyperledger/*" ],
      "@lib/*": [ "lib/*" ]
    },
    "plugins": [
      { "transform": "ts-transformer-keys/transformer" }
    ],
    "module": "CommonJS",
    "moduleResolution": "node",
    "target": "ES2020",
    "lib": [ "ESNext" ],
    "allowJs": false,
    "allowSyntheticDefaultImports": true,
    "allowUnreachableCode": false,
    "allowUnusedLabels": false,
    "alwaysStrict": true,
    "declaration": true,
    "declarationMap": true,
    "emitBOM": false,
    "emitDecoratorMetadata": true,
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "importsNotUsedAsValues": "error",
    "isolatedModules": true,
    "newLine": "LF",
    "noEmitOnError": true,
    "noUncheckedIndexedAccess": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "pretty": true,
    "resolveJsonModule": true,
    "skipLibCheck": true,
    "sourceMap": true,
    "strict": true,
    "stripInternal": true,
    "useDefineForClassFields": true
  },
  "include": [
    "src/**/*",
    "types/*.d.ts"
  ],
  "sourceRoot": "src"
}

[cspotcode]

Check out our compiler option which is documented in the README. Like many of our options, it can be specified via your tsconfig.json for convenience.

For example:

{
  "ts-node": {
    "files": true,
    "compiler": "ttypescript",
  },
  "compilerOptions": {
    "plugins": [
      { "transform": "ts-transformer-keys/transformer" }
    ]
  }
}

[cspotcode]

I updated my comment above to include a sample tsconfig.json

[robbiemu]

I cannot believe how awesome you have been to me today :) thank you man!

[cspotcode]

Excellent, I'm glad everything is working for you! You were kind enough to ask in the right place, and I'm sure your posts will help other users in the future. Cheers!