Merge #16943: test: Add generatetodescriptor RPC

fa144e6fde1f546a952023af715032cb6789d948 rpc: Add generatetodescriptor (MarcoFalke)

Pull request description:

  The existing `generatetoaddress` RPC can only generate to scriptPubKeys that can be represented by an address. However, raw scripts (such as `OP_TRUE`) or P2PK can not be represented by an address, which complicates testing.

ACKs for top commit:
  laanwj:
    ACK fa144e6fde1f546a952023af715032cb6789d948

Tree-SHA512: aee934ab7e33f07c81f3b4c8ec23e7b6ddf63a1f4b86051af0bd76b75d8da1f51627cc682e5c6e42582340ca576bbf8ff724bdd43f87128ccecfa91e52d30ae7

2 files changed, 46 insertions, 0 deletions

diff --git a/src/rpc/client.cpp b/src/rpc/client.cpp
index 32e18312e1..dfca1697c1 100644
--- a/src/rpc/client.cpp
+++ b/src/rpc/client.cpp
@@ -30,6 +30,8 @@ static const CRPCConvertParam vRPCConvertParams[] =
     { "utxoupdatepsbt", 1, "descriptors" },
     { "generatetoaddress", 0, "nblocks" },
     { "generatetoaddress", 2, "maxtries" },
+    { "generatetodescriptor", 0, "num_blocks" },
+    { "generatetodescriptor", 2, "maxtries" },
     { "getnetworkhashps", 0, "nblocks" },
     { "getnetworkhashps", 1, "height" },
     { "sendtoaddress", 1, "amount" },
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index bfa3e35d96..108ea0dfb8 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -19,7 +19,9 @@
 #include <rpc/blockchain.h>
 #include <rpc/server.h>
 #include <rpc/util.h>
+#include <script/descriptor.h>
 #include <script/script.h>
+#include <script/signingprovider.h>
 #include <shutdown.h>
 #include <txmempool.h>
 #include <univalue.h>
@@ -141,6 +143,47 @@ static UniValue generateBlocks(const CScript& coinbase_script, int nGenerate, ui
     return blockHashes;
 }
 
+static UniValue generatetodescriptor(const JSONRPCRequest& request)
+{
+    RPCHelpMan{
+        "generatetodescriptor",
+        "\nMine blocks immediately to a specified descriptor (before the RPC call returns)\n",
+        {
+            {"num_blocks", RPCArg::Type::NUM, RPCArg::Optional::NO, "How many blocks are generated immediately."},
+            {"descriptor", RPCArg::Type::STR, RPCArg::Optional::NO, "The descriptor to send the newly generated bitcoin to."},
+            {"maxtries", RPCArg::Type::NUM, /* default */ "1000000", "How many iterations to try."},
+        },
+        RPCResult{
+            "[ blockhashes ]     (array) hashes of blocks generated\n"},
+        RPCExamples{
+            "\nGenerate 11 blocks to mydesc\n" + HelpExampleCli("generatetodescriptor", "11 \"mydesc\"")},
+    }
+        .Check(request);
+
+    const int num_blocks{request.params[0].get_int()};
+    const int64_t max_tries{request.params[2].isNull() ? 1000000 : request.params[2].get_int()};
+
+    FlatSigningProvider key_provider;
+    std::string error;
+    const auto desc = Parse(request.params[1].get_str(), key_provider, error, /* require_checksum = */ false);
+    if (!desc) {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
+    }
+    if (desc->IsRange()) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Ranged descriptor not accepted. Maybe pass through deriveaddresses first?");
+    }
+
+    FlatSigningProvider provider;
+    std::vector<CScript> coinbase_script;
+    if (!desc->Expand(0, key_provider, coinbase_script, provider)) {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Cannot derive script without private keys"));
+    }
+
+    CHECK_NONFATAL(coinbase_script.size() == 1);
+
+    return generateBlocks(coinbase_script.at(0), num_blocks, max_tries);
+}
+
 static UniValue generatetoaddress(const JSONRPCRequest& request)
 {
             RPCHelpMan{"generatetoaddress",
@@ -962,6 +1005,7 @@ static const CRPCCommand commands[] =
 
 
     { "generating",         "generatetoaddress",      &generatetoaddress,      {"nblocks","address","maxtries"} },
+    { "generating",         "generatetodescriptor",   &generatetodescriptor,   {"num_blocks","descriptor","maxtries"} },
 
     { "util",               "estimatesmartfee",       &estimatesmartfee,       {"conf_target", "estimate_mode"} },