Unhandled AssertionError on the RPC endpoint

[gdassori]

The bcurl API raises an assertion error when an empty method is passed to the RPC execute method (https://github.com/bcoin-org/bcurl/blob/master/lib/client.js#L310).

The way the execute is used in the hsd and hsw client (super().execute) throw this bad exception right as a client response, when passing an empty method to the rpc command:

$ ./bin/hsd-cli rpc
AssertionError [ERR_ASSERTION]: Assertion failed.

This could be both a problem of bcurl, that doesn't throw an RPCError exception, or of the hs-client, that should catch the raw assertion and throw the error.

Knowing nothing, I tend to think that bcurl developers thought the execute method as private.

Intially I thought that a way to fix this could be to call the super().execute() inside a try\catch, and raise an RPCError.. but the RPCError is not exported by the client module, so I went into a loop and back to think as a bcurl "issue" (at least the dependency should be changed to export the class).

What do you think?

[pinheadmz]

Seems like we should be able to catch this mistake further up, maybe throwing an error in hsd-cli itself here if method is null:

hs-client/bin/hsd-cli

Line 179 in 200e906

const method = this.argv.shift();

and in hsw-cli here:

hs-client/bin/hsw-cli

Line 512 in 200e906

const method = this.argv.shift();

[pinheadmz]

Closed by #42