Is there a limit on the number of watched tasks?

[crystalfp]

Today I added a new directory to watch changing the number of tasks from 10 to 11 and suddenly the following warning appears:

> npm-watch      

No task specified. Will go through all possible tasks
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 unpipe listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(Use `node --trace-warnings ...` to show where the warning was created)
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 close listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 finish listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 unpipe listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 close listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
(node:22572) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 finish listeners added to [Transform]. Use emitter.setMaxListeners() to increase limit
[build:sass] [nodemon] 2.0.7
[build:server] [nodemon] 2.0.7
[build:server] [nodemon] watching path(s): server\**\*
[build:server] [nodemon] watching extensions: ts
[nodemon] starting `npm.cmd run -s build:server`
[build:html] [nodemon] 2.0.7
[build:html] [nodemon] watching path(s): client-widgets\**\*
[build:html] [nodemon] watching extensions: html
[build:html] [nodemon] starting `npm.cmd run -s build:html`
[build:widgets] [nodemon] 2.0.7
[build:widgets] [nodemon] watching path(s): client-widgets\**\*
[build:widgets] [nodemon] watching extensions: ts
[build:widgets] [nodemon] starting `npm.cmd run -s build:widgets`
[build:svg] [nodemon] 2.0.7
[build:svg] [nodemon] watching path(s): client\**\*
[build:svg] [nodemon] watching extensions: svg
[build:svg] [nodemon] starting `npm.cmd run -s build:svg`
[build:plugins] [nodemon] 2.0.7
[build:plugins] [nodemon] watching path(s): plugins\**\*
[build:plugins] [nodemon] watching extensions: ts
[build:plugins] [nodemon] starting `npm.cmd run -s build:plugins`
[build:client] [nodemon] 2.0.7
[build:client] [nodemon] watching path(s): client\**\*
[build:client] [nodemon] watching extensions: ts
[build:png] [nodemon] 2.0.7
[build:prepare] [nodemon] 2.0.7
[build:client] [nodemon] starting `npm.cmd run -s build:client`
[build:png] [nodemon] starting `npm.cmd run -s build:png`
[build:prepare] [nodemon] watching path(s): prepare\**\* common\**\*
[nodemon] watching extensions: ts
[nodemon] starting `npm.cmd run -s build:prepare`
[build:common] [nodemon] 2.0.7
[build:common] [nodemon] watching path(s): common\**\*
[build:common] [nodemon] watching extensions: ts
[build:common] [nodemon] starting `npm.cmd run -s build:common`
[build:ingest] [nodemon] 2.0.7
[build:ingest] [nodemon] watching path(s): ingest\**\*
[build:ingest] [nodemon] watching extensions: ts
[build:ingest] [nodemon] starting `npm.cmd run -s build:ingest`
[build:sass] [nodemon] clean exit - waiting for changes before restart
[build:common] [nodemon] clean exit - waiting for changes before restart
[build:prepare] [nodemon] clean exit - waiting for changes before restart
[build:svg] [nodemon] clean exit - waiting for changes before restart
[build:png] [nodemon] clean exit - waiting for changes before restart
[build:ingest] [nodemon] clean exit - waiting for changes before restart
[build:html] [nodemon] clean exit - waiting for changes before restart
[build:server] [nodemon] clean exit - waiting for changes before restart
[build:plugins] [nodemon] clean exit - waiting for changes before restart
[build:client] [nodemon] clean exit - waiting for changes before restart
[build:widgets] [nodemon] clean exit - waiting for changes before restart

The relevant section of package.json is:

  "watch": {
    "build:sass": {
      "patterns": [
        "client",
        "client-widgets"
      ],
      "extensions": "scss",
      "delay": 500
    },
    "build:svg": {
      "patterns": [
        "client"
      ],
      "extensions": "svg",
      "delay": 500
    },
    "build:png": {
      "patterns": [
        "client"
      ],
      "extensions": "png",
      "delay": 500
    },
    "build:html": {
      "patterns": [
        "client-widgets"
      ],
      "extensions": "html",
      "delay": 500
    },
    "build:widgets": {
      "patterns": [
        "client-widgets"
      ],
      "extensions": "ts",
      "delay": 500
    },
    "build:client": {
      "patterns": [
        "client"
      ],
      "extensions": "ts",
      "delay": 500
    },
    "build:server": {
      "patterns": [
        "server"
      ],
      "extensions": "ts",
      "delay": 500
    },
    "build:plugins": {
      "patterns": [
        "plugins"
      ],
      "extensions": "ts",
      "delay": 500
    },
    "build:common": {
      "patterns": [
        "common"
      ],
      "extensions": "ts",
      "delay": 500
    },
    "build:prepare": {
      "patterns": [
        "prepare",
        "common"
      ],
      "extensions": "ts",
      "delay": 500
    },
    "build:ingest": {
      "patterns": [
        "ingest"
      ],
      "extensions": "ts",
      "delay": 500
    }
  },

The 10 maximum tasks sound suspiciously as an hardcoded limit somewhere. Really don't know if this is a npm-watch or nodemon or node problem. Or do you have any suggestion to organize differently my build process? Thanks! BTW, I'm preparing a small example to reproduce the problem. Thanks! mario

[M-Zuber]

This a node limitation, you can read more here - https://nodejs.org/docs/latest/api/events.html#events_emitter_setmaxlisteners_n

That aside, thank you for bringing this to my attention, there will be a configuration option in the next release