# Problem loading an external module

**URL:** <https://discourse.nodered.org/t/problem-loading-an-external-module/83143>\
**Category:** General\
**Created:** [24 November 2023 06:14 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143 "2023-11-24T06:14:15Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 06:14 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/1 "2023-11-24T06:14:15Z")

</div>

I just tried to install an external module and use it within a function node, following the [docs](https://nodered.org/docs/user-guide/writing-functions#loading-additional-modules):

- within the function editor, I configured the external module (`javascript-interface-library -> JIL`)
- verified that `functionExternalModules` was set to true in my `settings.js` file and
- deployed without errors

The logs said

```auto
24 Nov 06:51:22 - [info] Modul wird installiert: javascript-interface-library, Version: latest
24 Nov 06:51:24 - [info] Installiertes Modul: javascript-interface-library
24 Nov 06:51:24 - [info] Flows werden gestartet
24 Nov 06:51:24 - [info] Flows sind gestartet

```

But, surprisingly, I could not find the folder `~/.node-red/externalModules/` mentioned in the docs - are they wrong here?

In the function node, I tried

```auto
const { ValueIsNonEmptyString } = JIL
return msg;

```

but that crashed with the message

```auto
TypeError: Cannot destructure property 'ValueIsNonEmptyString' of 'JIL' as it is undefined.

```

Does anybody know what is going wrong here?

Thanks in advance for any help!

Amendment:

- I am using the latest Node-RED 3.1 (installed approx. 3 days ago)
- `node --version` says `v21.2.0`
- `externalModules` in my `settings.js` is empty (i.e., set to defaults)

---

<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [24 November 2023 09:01 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/2 "2023-11-24T09:01:35Z")

</div>

> [@rozek](#):
>
> `const { ValueIsNonEmptyString } = JIL`

As the error indicates, you can't deconstruct JIL because it has already been `require`d. You have to do `JIL.ValueIsNonEmptyString( ... )`. Or possibly, you could do `const ValueIsNonEmptyString = JIL.ValueIsNonEmptyString` if you want to use the marginally shorter name.

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 13:11 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/3 "2023-11-24T13:11:01Z")

</div>

Well, since `const { ValueIsNonEmptyString } = JIL` is just another way of writing `const ValueIsNonEmptyString = JIL.ValueIsNonEmptyString` this response should definitely be wrong.

Nevertheless, I tried it and got the error `TypeError: Cannot read properties of undefined (reading 'ValueIsNonEmptyString')` instead

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [24 November 2023 13:46 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/4 "2023-11-24T13:46:46Z")

</div>

Can you select and export the function node and paste it here please, so we can try it.

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 13:52 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/5 "2023-11-24T13:52:20Z")

</div>

Sure, here it is

```auto
[
    {
        "id": "5248a8427f232978",
        "type": "inject",
        "z": "a38a9db5ce759685",
        "name": "",
        "props": [
            {
                "p": "payload"
            },
            {
                "p": "topic",
                "vt": "str"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "payload": "",
        "payloadType": "date",
        "x": 80,
        "y": 560,
        "wires": [
            [
                "ee86e89fa5ccab7b"
            ]
        ]
    },
    {
        "id": "ee86e89fa5ccab7b",
        "type": "function",
        "z": "a38a9db5ce759685",
        "name": "function 1",
        "func": "const { ValueIsNonEmptyString } = JIL\n\nreturn msg;",
        "outputs": 1,
        "timeout": 0,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [
            {
                "var": "JIL",
                "module": "javascript-interface-library"
            }
        ],
        "x": 240,
        "y": 560,
        "wires": [
            [
                "2acc049673067f0e"
            ]
        ]
    },
    {
        "id": "2acc049673067f0e",
        "type": "debug",
        "z": "a38a9db5ce759685",
        "name": "debug 3",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 400,
        "y": 560,
        "wires": []
    }
]

```

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [24 November 2023 14:15 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/6 "2023-11-24T14:15:38Z")

</div>

I see the same problem, I don't know why.

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 14:17 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/7 "2023-11-24T14:17:32Z")

</div>

thanks for testing...

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 20:15 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/8 "2023-11-24T20:15:11Z")

</div>

does anybody have any idea? I'm surprised that such a basic feature fails and nobody ever ran into the same situation...

And, no, I do not want any kind of workaround as I plan to publish the affected flow and do not want my users to start complicated installations...

---

<div class="post-metadata">

**Author:** ![TotallyInformation](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/totallyinformation/32/31_2.png) [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)\
**Post date:** [24 November 2023 20:35 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/9 "2023-11-24T20:35:48Z")

</div>

> [@rozek](#):
>
> I'm surprised that such a basic feature fails and nobody ever ran into the same situation...

It really isn't surprising that, out of 100's of thousands of possible npm libraries, some don't actually work.

Your first task should be to try a short test node.js file to see if the module actually works in Node.js at all. And in fact it doesn't.

```auto
Error [ERR_REQUIRE_ESM]: require() of ES Module D:\src\nr\data\node_modules\javascript-interface-library\dist\javascript-interface-library.js from D:\src\nr\data\settings.js not supported.
javascript-interface-library.js is treated as an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which declares all .js files in that package scope as ES modules.
Instead rename javascript-interface-library.js to end in .cjs, change the requiring code to use dynamic import() which is available in all CommonJS modules, or change "type": "module" to "type": "commonjs" in D:\src\nr\data\node_modules\javascript-interface-library\package.json to treat all .js files as CommonJS (using .mjs for all ES modules instead).

```

Maybe it could be finagled into working but life is too short I'm afraid.

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 20:39 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/10 "2023-11-24T20:39:10Z")

</div>

I just tried to create ~/.node-red/externalModules myself and got the following message

```auto
Node-RED 1.3 Verzeichnis externer Module erkannt:
    /Users/andreas/.node-red/externalModules
Dieses Verzeichnis wird nicht mehr verwendet. Die externen Module werden
in Ihrem Node-RED-Benutzerverzeichnis neu installiert:
   /Users/andreas/.node-red
Löschen Sie das alte externalModules-Verzeichnis, um diese Meldung abzustellen.

```

which basically says that the folder mentioned in the docs is not used any longer

Are there more mistakes in the docs in that area?

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 20:42 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/11 "2023-11-24T20:42:42Z")

</div>

strange...

I can `npm install javascript-interface-library` without any problems.

I do not add it to the `settings.js` file but to the list of modules needed for a function node (`functionExternalModules` is `true` in my `settings.js`)

Additionally, I don't see any error messages in my server log

Amendment: I just tried to analyze the error message given by TotallyInformation to see if there is a solution:

- "dynamic import" does not seem to be a solution as that is, by definition, asynchronous and could cause race conditions...
- changing "package.json" is also not an option as that could cause side-effects for other users of that library

---

<div class="post-metadata">

**Author:** ![ralphwetzel](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ralphwetzel/32/53713_2.png) [@ralphwetzel](https://discourse.nodered.org/u/ralphwetzel)\
**Post date:** [24 November 2023 21:15 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/12 "2023-11-24T21:15:50Z")

</div>

I could have an explanation for what you see:

> <https://github.com/node-red/node-red/blob/a55554193bac2ee4997948c6a15dd752844cace4/packages/node_modules/%40node-red/nodes/core/function/10-function.js#L316-L323>

After the function node imported an _ExternalModule_ as `lib`, it references (line 318) `lib.default` to the variable name defined on the property editor.

`lib.default` yet is only present if the module has defined an `export default` or `export { ..., ... as default, ...}`.

`javascript-interface-library` doesn't define an `export default`, but _only_ `export { ... }`.

Is this a bug of Node-RED? I'm not sure...

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 21:17 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/13 "2023-11-24T21:17:57Z")

</div>

THAT's interesting! So Node-RED requires importable libraries to define a default export!? I never knew that - and it also does not seem to be documented.

Thanks a lot for this detail!

~~Unfortunately, this means a LOT of ugly work for me...~~

Ok, so my current plan is

- create another module
- `import * as JIL from 'javascript-interface-library'`
- `export default JIL`

that should work, shouldn't it?

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 21:56 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/14 "2023-11-24T21:56:23Z")

</div>

will it ever work?

Now I get the following server log message:

```auto
24 Nov 22:54:13 - [error] [function:function 1] Fehler beim Laden des Moduls : TypeError: Cannot add property noConflict, object is not extensible
24 Nov 22:54:13 - [error] [function:function 1] Function node failed to load external modules

```

I do not know who wants to add a property `noConflict` to any object - it's definitely neither me nor the library...

But, according to `~/.node-red/node_modules`, both the auxiliary `node-red-javascript-interface-library` and its dependency, the actual `javascript-interface-library` were successfully installed...

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 22:08 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/15 "2023-11-24T22:08:02Z")

</div>

By the way: dynamic imports do not work in Node-RED

The code

```auto
(async () => {
  node.warn('loading JIL')
  const JIL = await import('javascript-interface-library')
  node.warn('JIL = ' + JIL)
})()

```

crashes the server with the following log output:

```auto
24 Nov 23:05:56 - [error] TypeError [ERR_VM_DYNAMIC_IMPORT_CALLBACK_MISSING]: A dynamic import callback was not specified.
    at importModuleDynamicallyCallback (node:internal/modules/esm/utils:192:9)
    at Function node:ee86e89fa5ccab7b [function 1]:4:15
    at Function node:ee86e89fa5ccab7b [function 1]:6:3
    at Function node:ee86e89fa5ccab7b [function 1]:8:3
    at Script.runInContext (node:vm:133:12)
    at processMessage (/Users/andreas/.nvm/versions/node/v21.2.0/lib/node_modules/node-red/node_modules/@node-red/nodes/core/function/10-function.js:419:33)
    at FunctionNode._inputCallback (/Users/andreas/.nvm/versions/node/v21.2.0/lib/node_modules/node-red/node_modules/@node-red/nodes/core/function/10-function.js:342:17)
    at /Users/andreas/.nvm/versions/node/v21.2.0/lib/node_modules/node-red/node_modules/@node-red/runtime/lib/nodes/Node.js:210:26
    at Object.trigger (/Users/andreas/.nvm/versions/node/v21.2.0/lib/node_modules/node-red/node_modules/@node-red/util/lib/hooks.js:166:13)
    at Node._emitInput (/Users/andreas/.nvm/versions/node/v21.2.0/lib/node_modules/node-red/node_modules/@node-red/runtime/lib/nodes/Node.js:202:11)

```

(and importing `node-red-javascript-interface-library`) doesn't work either

(giving up for today - I really did not expect that a simple module import could cause such a complete full-stop of my development...)

---

<div class="post-metadata">

**Author:** ![ralphwetzel](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ralphwetzel/32/53713_2.png) [@ralphwetzel](https://discourse.nodered.org/u/ralphwetzel)\
**Post date:** [24 November 2023 22:10 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/16 "2023-11-24T22:10:10Z")

</div>

> [@rozek](#):
>
> that should work, shouldn't it?

You could try - but I'm not sure:

The `import()` call to your module returns an empty object - which is significantly different to many other modules (randomly picked) I tested with. That's the true cause for this issue. Reason unclear...

Additionally, we should discuss (ping @Steve-Mcl) to change line 318 to sth like

```auto
sandbox[vname] = lib.default ? lib.default : lib;

```

This yet needs some investigation for side effects...

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 22:12 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/17 "2023-11-24T22:12:34Z")

</div>

no, I simply do not provide a default export from the `javascript-interface-library` - that's why I hacked the ugly `node-red-javascript-interface-library`.

But - as written - now a different error occurs after the successful module installation.

---

<div class="post-metadata">

**Author:** ![ralphwetzel](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ralphwetzel/32/53713_2.png) [@ralphwetzel](https://discourse.nodered.org/u/ralphwetzel)\
**Post date:** [24 November 2023 22:12 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/18 "2023-11-24T22:12:42Z")

</div>

> [@rozek](#):
>
> The code
> 
> ```auto
> (async () => {
> node.warn('loading JIL')
> const JIL = await import('javascript-interface-library')
> node.warn('JIL = ' + JIL)
> })()
> 
> ```
> 
> crashes the server with the following log output:

🤔 Where did you try to run this? In a function node? That's never going to work...

---

<div class="post-metadata">

**Author:** ![rozek](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/rozek/32/48594_2.png) [@rozek](https://discourse.nodered.org/u/rozek)\
**Post date:** [24 November 2023 22:13 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/19 "2023-11-24T22:13:14Z")

</div>

yes, in the function node - why shouldn't that work? it's standard JavaScript

Should I provide a complete URL?

Amendment: no, a complete URL will crash as well...

---

<div class="post-metadata">

**Author:** ![ralphwetzel](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ralphwetzel/32/53713_2.png) [@ralphwetzel](https://discourse.nodered.org/u/ralphwetzel)\
**Post date:** [24 November 2023 22:15 UTC](https://discourse.nodered.org/t/problem-loading-an-external-module/83143/20 "2023-11-24T22:15:41Z")

</div>

> [@rozek](#):
>
> it's standard JavaScript

Might be. But the `function` node code runs in a sandbox.  
If that was possible, why should there be the action with `functionExternalModules` ?

[Next page](https://discourse.nodered.org/t/problem-loading-an-external-module/83143.md?page=2)