Using standard javascript Set in code node not working

Questions
1

Using the javascript standard Set class does not seem to work in code nodes:

This gives an empty result:

1513×1058 69.9 KB

In this fiddle (pure Javascript, no libraries) it is working as expected:

  • n8n version: 1.38.2
  • Database (default: SQLite): sqlite
  • n8n EXECUTIONS_PROCESS setting (default: own, main): ??
  • Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
  • Operating system: Ubuntu 22.04
2

It looks like your topic is missing some important information. Could you provide the following if applicable.

  • n8n version:
  • Database (default: SQLite):
  • n8n EXECUTIONS_PROCESS setting (default: own, main):
  • Running n8n via (Docker, npm, n8n cloud, desktop app):
  • Operating system:
3

@einfachiso , try using this instead

Sets do not integrate with JSON, which is expected to be outputted by n8n node.

1 Like
4

Thank you for your answer, @ihortom.

It does not work either when I return example.values() however which is an array.

Also when I try to log any content of the Set to console the output is always empty as well.

So apparently adding to a Set does not work in n8n for some reason(?).

5

You still can use sets

This produces the same result as in the output of the 1st workaround. You would have to convert sets to arrays as in Array.from(set).

2 Likes
6

Using Array.from(set) is definitely a good solution here.
The underlying issue is that the code node runs JS in a sandbox, and any data that needs to be pulled out of the sandbox has to go through serialization/de-serialization.
The sandbox (just like JSON.stringify) doesn’t know how to serialize Sets and Maps, and converts objects like these to {}.

2 Likes
7

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