fix: block filters can be also recreated

Author: AuHau

ethers/providers/jsonrpc/subscriptions.nim

@@ -164,8 +164,14 @@ proc new*(_: type JsonRpcSubscriptions,
       raise e
     except CatchableError as e:
       if "filter not found" in e.msg:
-        let filter = subscriptions.filters[originalId]
-        let newId = await subscriptions.client.eth_newFilter(filter)
+        var newId: JsonNode
+        # If there exists filter for given ID, then the filter was a log filter
+        # otherwise it was a block filter
+        if subscriptions.filters.hasKey(originalId):
+          let filter = subscriptions.filters[originalId]
+          newId = await subscriptions.client.eth_newFilter(filter)
+        else:
+          newId = await subscriptions.client.eth_newBlockFilter()
         subscriptions.subscriptionMapping[originalId] = newId
         return await getChanges(originalId)
       else:

testmodule/providers/jsonrpc/rpc_mock.nim

@@ -25,6 +25,11 @@ proc start*(server: MockRpcHttpServer) =
     server.filters.add filterId
     return filterId
 
+  server.srv.router.rpc("eth_newBlockFilter") do() -> string:
+    let filterId = "0x" & (array[16, byte].example).toHex
+    server.filters.add filterId
+    return filterId
+
   server.srv.router.rpc("eth_getFilterChanges") do(id: string) -> seq[string]:
     if id notin server.filters:
       raise (ref ApplicationError)(code: -32000, msg: "filter not found")

testmodule/providers/jsonrpc/testJsonRpcSubscriptions.nim

@@ -124,7 +124,7 @@ suite "HTTP polling subscriptions - filter not found":
     await client.close()
     await mockServer.stop()
 
-  test "filter not found error recreates filter":
+  test "filter not found error recreates log filter":
     let filter = EventFilter(address: Address.example, topics: @[array[32, byte].example])
     let emptyHandler = proc(log: Log) = discard
 
@@ -142,7 +142,7 @@ suite "HTTP polling subscriptions - filter not found":
 
     check eventually subscriptions.subscriptionMapping[id] != id
 
-  test "recreated filter can be still unsubscribed using the original id":
+  test "recreated log filter can be still unsubscribed using the original id":
     let filter = EventFilter(address: Address.example, topics: @[array[32, byte].example])
     let emptyHandler = proc(log: Log) = discard
     let id = await subscriptions.subscribeLogs(filter, emptyHandler)
@@ -153,3 +153,24 @@ suite "HTTP polling subscriptions - filter not found":
 
     check not subscriptions.filters.hasKey id
     check not subscriptions.subscriptionMapping.hasKey id
+
+  test "filter not found error recreates block filter":
+    let emptyHandler = proc(blck: Block) = discard
+
+    check subscriptions.subscriptionMapping.len == 0
+    let id = await subscriptions.subscribeBlocks(emptyHandler)
+    check subscriptions.subscriptionMapping[id] == id
+
+    mockServer.invalidateFilter(id)
+
+    check eventually subscriptions.subscriptionMapping[id] != id
+
+  test "recreated block filter can be still unsubscribed using the original id":
+    let emptyHandler = proc(blck: Block) = discard
+    let id = await subscriptions.subscribeBlocks(emptyHandler)
+    mockServer.invalidateFilter(id)
+    check eventually subscriptions.subscriptionMapping[id] != id
+
+    await subscriptions.unsubscribe(id)
+
+    check not subscriptions.subscriptionMapping.hasKey id