Ralf Praschak

i am trying to combine a Max patch with NestJS. The first basic steps worked so far. Starting the NestJS Application from Max.

Now i created a Max service for interacting with Max. Running standalone creates an expected error:

But within Max i am getting also an error:

TypeError: Cannot read properties of undefined (reading: post)

import { Injectable, Logger } from "@nestjs/common";
import maxAPI from 'max-api';

@Injectable()
export class MaxService {
  private readonly logger = new Logger(MaxService.name);

  onApplicationBootstrap() {
    this.logger.log('Doing something...');
    maxAPI.post(`Running in MAX_ENV: ${process.env.MAX_ENV as string}`);
  }
}

And is there some kind of workaround to run the NestJS app standalone without max-api?

Hello,

i am trying to combine a Max patch with NestJS. The first basic steps worked so far. Starting the NestJS Application from Max.

Now...

error-cannot-find-module-max-api-using-typescript-and-nestjs

Adding esModuleInterop to the tsconfig.json fixed the TypeError within Max:

glad you got it working. I think your best bet to get to use your NestJS application standalone and with Max via 

 is to encapsulate the part that uses the 

 in a module and then determine at runtime whether to dynamically import it or if you'd like to use other functionality.

As already shown in your code you can rely upon 

) to determine if the script has been started from Max or outside of it.

One way to abstract that is to wrap the logic in your MaxService, maybe similar to this:

import { Injectable, Logger } from "@nestjs/common";

@Injectable()
export class MaxService {
  
  private readonly logger = new Logger(MaxService.name);
  private readonly isInMax = process.env.MAX_ENV !== undefined;

  onApplicationBootstrap() {
    this.logger.log('Doing something...');
    if (this.isInMax) {
      maxAPI.post(`Running in MAX_ENV: ${process.env.MAX_ENV as string}`);
    } else {
      // Do something different!?
    }
  }

}

or alternative you can write a module that implements the API of 

 and at runtime decide whether to load that or the one provided by 

. The API to implement is available as part of the 

Something like the following should work assuming that you provide some sort of 

const modPath = process.env.MAX_ENV !== undefined ? "max-api" : "./max-api.mock.js";
const maxAPI = await import(modPath);

thx alot for your reply and ideas. I guess, i'll try a mock for this - tomorrow. 

import { Injectable, Logger } from '@nestjs/common'
import MaxAPIStatic from 'max-api'

@Injectable()
export class MaxService {
  private readonly logger = new Logger(MaxService.name)
  private readonly isInMax = process.env.MAX_ENV !== undefined

  async onApplicationBootstrap() {
    if (!this.isInMax) {
      this.logger.warn('maxApi missing!')
      return
    }

    const maxAPI = await this.loadMaxModule('max-api')

    maxAPI.post(`Running in MAX_ENV: ${process.env.MAX_ENV}`)

    maxAPI.addHandler('onTest', (event) => {
      this.logger.log('onTest', event)

      maxAPI.outlet('result', Math.random())
    })
  }

  async loadMaxModule(modulePath: string): Promise<typeof MaxAPIStatic> {
    const module = await import(modulePath)
    return module.default as typeof MaxAPIStatic
  }
}

Error: Cannot find module 'max-api' (using Typescript and NestJS)