rpc: add RPCTypeCheck for getblockfrompeer inputs

Author: jonatack

src/rpc/blockchain.cpp

@@ -439,6 +439,11 @@ static RPCHelpMan getblockfrompeer()
         },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
+    RPCTypeCheck(request.params, {
+        UniValue::VSTR, // blockhash
+        UniValue::VNUM, // peer_id
+    });
+
     const NodeContext& node = EnsureAnyNodeContext(request.context);
     ChainstateManager& chainman = EnsureChainman(node);
     PeerManager& peerman = EnsurePeerman(node);

test/functional/rpc_getblockfrompeer.py

@@ -51,8 +51,8 @@ def run_test(self):
 
         self.log.info("Arguments must be valid")
         assert_raises_rpc_error(-8, "hash must be of length 64 (not 4, for '1234')", self.nodes[0].getblockfrompeer, "1234", peer_0_peer_1_id)
-        assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].getblockfrompeer, 1234, peer_0_peer_1_id)
-        assert_raises_rpc_error(-1, "JSON value is not an integer as expected", self.nodes[0].getblockfrompeer, short_tip, "0")
+        assert_raises_rpc_error(-3, "Expected type string, got number", self.nodes[0].getblockfrompeer, 1234, peer_0_peer_1_id)
+        assert_raises_rpc_error(-3, "Expected type number, got string", self.nodes[0].getblockfrompeer, short_tip, "0")
 
         self.log.info("We must already have the header")
         assert_raises_rpc_error(-1, "Block header missing", self.nodes[0].getblockfrompeer, "00" * 32, 0)