feat: add pallets/events endpoint

[marshacb]

Summary: An endpoint that returns the events for a given pallet

/pallets/{palletId}/events

Query Params

• at: Which block to query, it will default to the latest finalized block. Accepts a hash or blocknumber
• onlyIds: boolean to return only the Id of each event instead of the entirety of each event

Sample response for /pallets/democracy/events?onlyIds=true

{
	"at": {
		"hash": "0xc0403e7dcfa588573c4408a0c022c62049acf00d5cae78ef767eddf88d3dbf40",
		"height": "13974876"
	},
	"pallet": "democracy",
	"palletIndex": "14",
	"items": [
		"Proposed",
		"Tabled",
		"ExternalTabled",
		"Started",
		"Passed",
		"NotPassed",
		"Cancelled",
		"Delegated",
		"Undelegated",
		"Vetoed",
		"Blacklisted",
		"Voted",
		"Seconded",
		"ProposalCanceled"
	]
}

/pallets/{palletId}/events/{eventItemId}

Query Params

• at: Which block to query, it will default to the latest finalized block. Accepts a hash or blocknumber
• metadata: boolean to choose whether to include an events' metadata in the response

Sample response for /pallets/democracy/events/ExternalTabled

{
	"at": {
		"hash": "0xbb6693f2307bb78f26189640cc6a8f340a094f291e42435e4e25fb81f73bd874",
		"height": "13974886"
	},
	"pallet": "democracy",
	"palletIndex": "14",
	"eventItem": "externalTabled"
}

[TarikGul]

Overall, really great job just a few nits

[TarikGul]

Awesome, Great Job! 👍

[Imod7]

While connected to Kusama and testing the events endpoint
http://127.0.0.1:8080/pallets/12/events

I get the following result

{
  "code": 400,
  "message": "\"12\" was not recognized as a queryable pallet.",
  "stack": "BadRequestError: \"12\" was not recognized as a queryable pallet.\n    at PalletsEventsService.findPalletMeta (/Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/services/AbstractPalletsService.js:91:19)\n    at PalletsEventsService.fetchEvents (/Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/services/pallets/PalletsEventsService.js:48:50)\n    at PalletsEventsController.getEvents (/Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/controllers/pallets/PalletsEventsController.js:43:75)\n    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)\n    at async /Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/controllers/AbstractController.js:226:9",
  "level": "error"
}

and this means that pallet 12 (AuthorityDiscovery pallet) has no events to query right ?

Isn't the error message

"message": "\"12\" was not recognized as a queryable pallet."

a little bit misleading though ? From this error message I understand that there is no pallet with this index instead of saying that the are no events in this pallet to query.

I believe this error message is triggered here so I was wondering if it is easy to check and add a more explanatory error message in the case of the info missing in the specific pallet. The same happens when I query the errors endpoint also. Just an idea in case it is possible.

[marshacb]

While connected to Kusama and testing the events endpoint http://127.0.0.1:8080/pallets/12/events

I get the following result

{
  "code": 400,
  "message": "\"12\" was not recognized as a queryable pallet.",
  "stack": "BadRequestError: \"12\" was not recognized as a queryable pallet.\n    at PalletsEventsService.findPalletMeta (/Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/services/AbstractPalletsService.js:91:19)\n    at PalletsEventsService.fetchEvents (/Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/services/pallets/PalletsEventsService.js:48:50)\n    at PalletsEventsController.getEvents (/Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/controllers/pallets/PalletsEventsController.js:43:75)\n    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)\n    at async /Users/tiny_imod/Documents/Parity/substrate-api-sidecar/build/src/controllers/AbstractController.js:226:9",
  "level": "error"
}

and this means that pallet 12 (AuthorityDiscovery pallet) has no events to query right ?

Isn't the error message

"message": "\"12\" was not recognized as a queryable pallet."

a little bit misleading though ? From this error message I understand that there is no pallet with this index instead of saying that the are no events in this pallet to query.

I believe this error message is triggered here so I was wondering if it is easy to check and add a more explanatory error message in the case of the info missing in the specific pallet. The same happens when I query the errors endpoint also. Just an idea in case it is possible.

Thats correct. AuthorityDiscovery has no events currently and so we throw an error when querying for them. I've updated the error message to reflect that the items for the specific field of a pallets metadata aren't found rather than reflecting that the pallet id itself is not valid. This will also update the response for errors and other pallets endpoints.

[Imod7]

When I request the events of the utility pallet while connected to Kusama :
✅ I get the response with the events when I query by pallet index
❌ I get an error message when I query by pallet name

From what I have seen this only happens for the Utility pallet.

[Imod7]

Tested again and now it works like a charm! 💯 Awesome !