add eth_subscribe and eth_unsubscribe

[Shiti]

This is implemented and supported by the most execution clients. For example:

• Geth
• Nethermind

I could not find the EIP or other document where this was discussed.

[lightclient]

Hi @Shiti, thank you for this contribution. In addition to the spec update, we also need to generate tests. You can learn how to do this here: https://github.com/ethereum/execution-apis/blob/main/tests/README.md

[Shiti]

@lightclient I'm unable to get the tests to pass.

Here's an example,

>> {"jsonrpc":"2.0","id":1,"method":"eth_subscribe","params":["newHeads"]}
<< {"jsonrpc":"2.0","id":1,"result":"0xcd0c3e8af590364c09d0fa6a1210faf5"}

The errors in the logs from failure are:

>>  {"jsonrpc":"2.0","id":1,"method":"eth_subscribe","params":["newHeads"]}
<<  {"jsonrpc":"2.0","id":1,"error":{"code":-32001,"message":"notifications not supported"}}
response differs from expected:
 {
-  "error": {
-    "code": -32001,
-    "message": "notifications not supported"
-  },
   "id": 1,
   "jsonrpc": "2.0"
+  "result": "0xcd0c3e8af590364c09d0fa6a1210faf5"
 }


>>  {"jsonrpc":"2.0","id":1,"method":"eth_subscribe","params":["newHeads"]}
<<  {"jsonrpc":"2.0","error":{"code":-32600,"message":"eth_subscribe found for the url 'http://0.0.0.0:8545' but is disabled for Https"},"id":1}
response differs from expected:
 {
-  "error": {
-    "code": -32600,
-    "message": "eth_subscribe found for the url 'http://0.0.0.0:8545' but is disabled for Https"
-  },
   "id": 1,
   "jsonrpc": "2.0"
+  "result": "0xcd0c3e8af590364c09d0fa6a1210faf5"
 }

Is it disabled intentionally for testing ?

At this time, this precludes subscription methods from being tested.
https://github.com/ethereum/execution-apis/blob/main/tests/README.md#test-generation

Please guide me on how to proceed.

[shanejonas]

"message": "eth_subscribe found for the url 'http://0.0.0.0:8545' but is disabled for Https"

these methods are only available over websocket

[fjl]

I don't think it will be possible to create example driven tests for this mechanism. For eth_subscribe, the server generates the subscription ID, and it will usually be a large random value. Our testing framework cannot deal with non-deterministic responses.