feature: JSONata Expression editor enable testing of $flowContext and $globalContext

[yue-wen]

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Proposed changes

Enable JSONata expression editor testing $flowContext and $globalContext with node-red context data.

Test flow:

[{"id":"5567d268351f2b7d","type":"change","z":"f510d69f121b9ae7","name":"","rules":[{"t":"set","p":"flow.string","pt":"msg","to":"$flowContext(\"string\")\t","tot":"jsonata"},{"t":"set","p":"global.string","pt":"msg","to":"$globalContext(\"string\")","tot":"jsonata"},{"t":"set","p":"flow.number","pt":"msg","to":"$flowContext(\"number\")\t","tot":"jsonata"},{"t":"set","p":"global.number","pt":"msg","to":"$globalContext(\"number\")","tot":"jsonata"},{"t":"set","p":"flow.boolean","pt":"msg","to":"$flowContext(\"boolean\")\t","tot":"jsonata"},{"t":"set","p":"global.boolean","pt":"msg","to":"$globalContext(\"boolean\")","tot":"jsonata"},{"t":"set","p":"flow.json","pt":"msg","to":"$flowContext(\"json\")\t","tot":"jsonata"},{"t":"set","p":"global.json","pt":"msg","to":"$globalContext(\"json\")","tot":"jsonata"},{"t":"set","p":"flow.timestemp","pt":"msg","to":"$flowContext(\"timestemp\")\t","tot":"jsonata"},{"t":"set","p":"global.timestemp","pt":"msg","to":"$globalContext(\"timestemp\")","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":310,"y":260,"wires":[["309683aa2f529758"]]},{"id":"ddf8409581203ca3","type":"inject","z":"f510d69f121b9ae7","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":100,"y":260,"wires":[["5567d268351f2b7d"]]},{"id":"309683aa2f529758","type":"debug","z":"f510d69f121b9ae7","name":"debug 1","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":500,"y":260,"wires":[]},{"id":"06ff51c3a7b2c2d7","type":"config","z":"f510d69f121b9ae7","name":"","properties":[{"p":"string","pt":"flow","to":"string","tot":"str"},{"p":"number","pt":"flow","to":"123","tot":"num"},{"p":"boolean","pt":"flow","to":"true","tot":"bool"},{"p":"json","pt":"flow","to":"{\"json\":{\"format\":true}}","tot":"json"},{"p":"timestemp","pt":"flow","to":"","tot":"date"},{"p":"string","pt":"global","to":"string","tot":"str"},{"p":"number","pt":"global","to":"123","tot":"num"},{"p":"boolean","pt":"global","to":"true","tot":"bool"},{"p":"json","pt":"global","to":"{\"json\":{\"format\":true}}","tot":"json"},{"p":"timestemp","pt":"global","to":"","tot":"date"}],"active":true,"x":90,"y":200,"wires":[]}]

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the forum/slack team.
• I have run grunt to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: yue-wen / name: Yuewen Liu (1fa35722f40a98010a8acba5583f5a27184fee4a)

[yue-wen]

I have one failed tests, but I am pretty sure it not casued by my change.

  2422 passing (3m)
  59 pending
  1 failing

  1) file Nodes
       file out Node
         should fail to create a new directory if not asked to do so (overwrite):
     AssertionError: expected Array [] to have property length of 1 (got 0)
      at Assertion.fail (node_modules/should/cjs/should.js:275:17)
      at Assertion.value (node_modules/should/cjs/should.js:356:19)
      at Timeout._onTimeout (test/nodes/core/storage/10-file_spec.js:631:47)
      at listOnTimeout (internal/timers.js:557:17)
      at processTimers (internal/timers.js:500:7)

enviroment:

node: v14.21.2
OS: ubuntu 22.04

[knolleary]

Hi @yue-wen

thank you for this PR. You have linked to a two year old thread on the forum, rather than any active discussion on whether this is something we want to enable in the editor. There are reasons we chose not to support the context functions - mostly due to the overhead of loading context data in the editor.

Your approach appears to get all context data just in case it is needed - that is not very ideal if there is a large amount of data stored.

If we wanted to add support for the flow/globalContext functions, the code would need to be much more selective over what it loads and when. For example, only loading context data if those functions are actually being used.

There is also the matter of how it handles multiple context stores, rather than just the default one. We'd need to look at how that would have to modify the logic around what gets loaded.

Finally, to get the current flow id you should use RED.workspaces.active(), not parsing the url.

And one more thing... as this would be a new feature, it should target the dev branch, not master. This is explained in https://github.com/node-red/node-red/blob/master/CONTRIBUTING.md

[yue-wen]

Hi @knolleary
Thank you for your reply.
sorry about forum link and wrong branch.

I understand your consider about overhead of loading context data.

Because the response schema of context endpoint, I thought context api only return data of default store.
It seems that I misunderstood.

$curl -s 'http://localhost:1880/context/global' | jq

{
  "memory": {
    "string": {
      "msg": "string",
      "format": "string[6]"
    },
    "number": {
      "msg": "123",
      "format": "string[3]"
    },
    "boolean": {
      "msg": "true",
      "format": "boolean"
    },
    "json": {
      "msg": "{\"json\":{\"format\":true}}",
      "format": "Object"
    },
    "timestemp": {
      "msg": "1673608294518",
      "format": "number"
    }
  }
}

I will try refactor my code to loading context data only once when it being used.