add raises to close functions (#245)

although these functions don't quite follow chronos 4 naming standards
(`closeWait` for `async` waiting close, `close` for sync background
close, `join` for `close` notification), they still shouldn't raise
exceptions, ever, and should not allow themselves to be cancelled (to
simplify reasoning about closing)

Author: arnetheduck

json_rpc/client.nim

@@ -140,7 +140,7 @@ proc call*(client: RpcClient, name: string,
                {.async: (raw: true).} =
   client.call(name, params.paramsTx)
 
-method close*(client: RpcClient): Future[void] {.base, async.} =
+method close*(client: RpcClient): Future[void] {.base, async: (raises: []).} =
   raiseAssert("`RpcClient.close` not implemented")
 
 method callBatch*(client: RpcClient,

json_rpc/clients/httpclient.nim

@@ -220,7 +220,7 @@ proc connect*(client: RpcHttpClient, address: string, port: Port, secure: bool)
   client.httpAddress = getAddress(client.httpSession, uri).valueOr:
     raise newException(RpcAddressUnresolvableError, error)
 
-method close*(client: RpcHttpClient) {.async.} =
+method close*(client: RpcHttpClient) {.async: (raises: []).} =
   if not client.httpSession.isNil:
     await client.httpSession.closeWait()
 

json_rpc/clients/socketclient.nim

@@ -135,7 +135,7 @@ proc connect*(client: RpcSocketClient, address: TransportAddress) {.async.} =
   client.address = address
   client.loop = processData(client)
 
-method close*(client: RpcSocketClient) {.async.} =
+method close*(client: RpcSocketClient) {.async: (raises: []).} =
   await client.loop.cancelAndWait()
   if not client.transport.isNil:
     client.transport.close()

json_rpc/clients/websocketclientimpl.nim

@@ -151,8 +151,12 @@ proc connect*(
   client.uri = uri
   client.loop = processData(client)
 
-method close*(client: RpcWebSocketClient) {.async.} =
+method close*(client: RpcWebSocketClient) {.async: (raises: []).} =
   await client.loop.cancelAndWait()
   if not client.transport.isNil:
-    await client.transport.close()
+    try:
+      # TODO https://github.com/status-im/nim-websock/pull/178
+      await noCancel client.transport.close()
+    except CatchableError as exc:
+      warn "Unexpected exception while closing transport", err = exc.msg
     client.transport = nil

json_rpc/rpcproxy.nim

@@ -120,11 +120,11 @@ proc registerProxyMethod*(proxy: var RpcProxy, methodName: string) =
     # Adding proc type to table gives invalid exception tracking, see Nim bug: https://github.com/nim-lang/Nim/issues/18376
     raiseAssert err.msg
 
-proc stop*(proxy: RpcProxy) {.async.} =
+proc stop*(proxy: RpcProxy) {.async: (raises: []).} =
   await proxy.getClient().close()
   await proxy.rpcHttpServer.stop()
 
-proc closeWait*(proxy: RpcProxy) {.async.} =
+proc closeWait*(proxy: RpcProxy) {.async: (raises: []).} =
   await proxy.rpcHttpServer.closeWait()
 
 func localAddress*(proxy: RpcProxy): seq[TransportAddress] =

json_rpc/servers/httpserver.nim

@@ -258,13 +258,13 @@ proc start*(server: RpcHttpServer) =
     info "Starting JSON-RPC HTTP server", url = item.baseUri
     item.start()
 
-proc stop*(server: RpcHttpServer) {.async.} =
+proc stop*(server: RpcHttpServer) {.async: (raises: []).} =
   ## Stop the RPC server.
   for item in server.httpServers:
     await item.stop()
     info "Stopped JSON-RPC HTTP server", url = item.baseUri
 
-proc closeWait*(server: RpcHttpServer) {.async.} =
+proc closeWait*(server: RpcHttpServer) {.async: (raises: []).} =
   ## Cleanup resources of RPC server.
   for item in server.httpServers:
     await item.closeWait()

json_rpc/servers/socketserver.nim

@@ -127,7 +127,7 @@ proc close*(server: RpcSocketServer) =
   for item in server.servers:
     item.close()
 
-proc closeWait*(server: RpcSocketServer) {.async.} =
+proc closeWait*(server: RpcSocketServer) {.async: (raises: []).} =
   ## Cleanup resources of RPC server.
   for item in server.servers:
     await item.closeWait()

json_rpc/servers/websocketserver.nim

@@ -12,9 +12,7 @@
 import
   chronicles, chronos, websock/[websock, types],
   websock/extensions/compression/deflate,
-  stew/byteutils,
   json_serialization/std/net as jsnet,
-
   ../[errors, server]
 
 export errors, server, jsnet
@@ -246,7 +244,7 @@ proc close*(server: RpcWebSocketServer) =
   ## Cleanup resources of RPC server.
   server.server.close()
 
-proc closeWait*(server: RpcWebSocketServer) {.async.} =
+proc closeWait*(server: RpcWebSocketServer) {.async: (raises: []).} =
   ## Cleanup resources of RPC server.
   await server.server.closeWait()