Merge bitcoin/bitcoin#24944: rpc: add getblockfrompeer RPCTypeCheck and invalid input test coverage

2ef5294 rpc: add RPCTypeCheck for getblockfrompeer inputs (Jon Atack)
734b966 test: add getblockfrompeer coverage of invalid inputs (Jon Atack)

Pull request description:

  The new getblockfrompeer RPC lacks test coverage for invalid arguments, and its error messages are not harmonized with the existing RPCs.

  Fix all issues.

ACKs for top commit:
  brunoerg:
    ACK 2ef5294

Tree-SHA512: 454782cf6a44fd0e05483bb152153667ef5c8021358385ddcf89724fbbbd35e187362bdff757e00c99319527bc4c0b20c7187f67241d4585d767a29787142f25

Author: MacroFake

src/rpc/blockchain.cpp

@@ -440,6 +440,11 @@ 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

@@ -54,14 +54,17 @@ def run_test(self):
         assert_equal(len(peers), 1)
         peer_0_peer_1_id = peers[0]["id"]
 
-        self.log.info("Arguments must be sensible")
-        assert_raises_rpc_error(-8, "hash must be of length 64 (not 4, for '1234')", self.nodes[0].getblockfrompeer, "1234", 0)
+        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(-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)
 
         self.log.info("Non-existent peer generates error")
-        assert_raises_rpc_error(-1, "Peer does not exist", self.nodes[0].getblockfrompeer, short_tip, peer_0_peer_1_id + 1)
+        for peer_id in [-1, peer_0_peer_1_id + 1]:
+            assert_raises_rpc_error(-1, "Peer does not exist", self.nodes[0].getblockfrompeer, short_tip, peer_id)
 
         self.log.info("Fetching from pre-segwit peer generates error")
         self.nodes[0].add_p2p_connection(P2PInterface(), services=P2P_SERVICES & ~NODE_WITNESS)