feat: catch dot port missing early

[j4m1ef0rd]

Pull Request

Closes: PRO-881

Checklist

Please conduct a thorough self-review before opening the PR.

• I am confident that the code works.
• I have updated documentation where appropriate.

Summary

Added a check to the validate settings code for the Dot settings that checks that the port number exist for all endpoints.
This catches the error early and gives a nice error message.

Error: Error reading settings

Caused by:
    Polkadot node endpoints must include a port number: No port found in url: http://loc****

[linear]

PRO-881 Error should notify that only Polkadot requires a port to be specified

From one of the mainnet validators:

—

if I omit port in the setting:

[dot]
ws_node_endpoint = "wss://my-testnet:443"
http_node_endpoint = "https://my-testnet:443"

it gives error: Error: Networking or low-level protocol error: Invalid Url: Port number is missing in the URL

—

Because the other chains don't require the port, only Polkadot does, it is confusing.

[j4m1ef0rd]

I'm getting some unexpected behaviour from the URL crate, it seems to follow this logic. If wss or https is used with a non default port, it will return None as the port number.
This means that the example endpoints we have used in many places are invalid:

• wss://my_fake_polkadot_rpc:443/<secret_key>, should be port 8080.
• https://my_fake_polkadot_rpc:443/<secret_key>, should be port 80.

Can you confirm that we will not support wss or https endpoints on port 443?

[codecov]

Codecov Report

Merging #4082 (3d94e74) into main (73f5d59) will decrease coverage by 0%.
Report is 21 commits behind head on main.
The diff coverage is 98%.

@@          Coverage Diff           @@
##            main   #4082    +/-   ##
======================================
- Coverage     71%     71%    -0%     
======================================
  Files        376     377     +1     
  Lines      59703   60078   +375     
  Branches   59703   60078   +375     
======================================
+ Hits       42599   42804   +205     
- Misses     14961   15025    +64     
- Partials    2143    2249   +106     

Files	Coverage Δ
engine/src/settings.rs	86% <98%> (+1%)	⬆️

... and 42 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[kylezs]

For visibility:
This won't handle the case we're trying to handle - Jamie to look into it tomorrow :)

[kylezs]

this map error should be able to be pulled out too? - thus removing the need for the const too

[kylezs]

let validate_dot_endpoints = |endpoints: &WsHttpEndpoints| -> Result<(), ConfigError> {
			validate_port_exists(&endpoints.ws_endpoint)
				.and_then(|_| validate_port_exists(&endpoints.http_endpoint))
				.map_err(|e| {
					ConfigError::Message(format!(
						"Polkadot node endpoints must include a port number: {e}"
					))
				})
		};