Merge #20556: rpc: Properly document return values (submitblock, gettxout, getblocktemplate, scantxoutset)

fa7ff07 rpc: Properly document submitblock return value (MarcoFalke)
fae542c rpc: Properly document getblocktemplate return value (MarcoFalke)
fabaccf rpc: Properly document scantxoutset return value (MarcoFalke)
faa2059 rpc: Properly document gettxout return value (MarcoFalke)

Pull request description:

  Currently a few return values are undocumented. This is causing confusion at the least. See for example #18476

ACKs for top commit:
  fjahr:
    utACK fa7ff07
  amitiuttarwar:
    tACK fa7ff07

Tree-SHA512: 933cb8f003163d93dbedb302d4c162514c2698ec6d58dbb9a053da8b8b9a4459b0701a3d9e830ecdabd7f278a46b7a07a3af49ec60703a80fcd75390877294ea

Author: fanquake

src/rpc/blockchain.cpp

@@ -1100,30 +1100,29 @@ static RPCHelpMan gettxoutsetinfo()
 static RPCHelpMan gettxout()
 {
     return RPCHelpMan{"gettxout",
-                "\nReturns details about an unspent transaction output.\n",
-                {
-                    {"txid", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction id"},
-                    {"n", RPCArg::Type::NUM, RPCArg::Optional::NO, "vout number"},
-                    {"include_mempool", RPCArg::Type::BOOL, /* default */ "true", "Whether to include the mempool. Note that an unspent output that is spent in the mempool won't appear."},
-                },
-                RPCResult{
-                    RPCResult::Type::OBJ, "", "",
-                    {
-                        {RPCResult::Type::STR_HEX, "bestblock", "The hash of the block at the tip of the chain"},
-                        {RPCResult::Type::NUM, "confirmations", "The number of confirmations"},
-                        {RPCResult::Type::STR_AMOUNT, "value", "The transaction value in " + CURRENCY_UNIT},
-                        {RPCResult::Type::OBJ, "scriptPubKey", "",
-                            {
-                                {RPCResult::Type::STR_HEX, "asm", ""},
-                                {RPCResult::Type::STR_HEX, "hex", ""},
-                                {RPCResult::Type::NUM, "reqSigs", "Number of required signatures"},
-                                {RPCResult::Type::STR_HEX, "type", "The type, eg pubkeyhash"},
-                                {RPCResult::Type::ARR, "addresses", "array of bitcoin addresses",
-                                    {{RPCResult::Type::STR, "address", "bitcoin address"}}},
-                            }},
-                        {RPCResult::Type::BOOL, "coinbase", "Coinbase or not"},
-                    }},
-                RPCExamples{
+        "\nReturns details about an unspent transaction output.\n",
+        {
+            {"txid", RPCArg::Type::STR, RPCArg::Optional::NO, "The transaction id"},
+            {"n", RPCArg::Type::NUM, RPCArg::Optional::NO, "vout number"},
+            {"include_mempool", RPCArg::Type::BOOL, /* default */ "true", "Whether to include the mempool. Note that an unspent output that is spent in the mempool won't appear."},
+        },
+        {
+            RPCResult{"If the UTXO was not found", RPCResult::Type::NONE, "", ""},
+            RPCResult{"Otherwise", RPCResult::Type::OBJ, "", "", {
+                {RPCResult::Type::STR_HEX, "bestblock", "The hash of the block at the tip of the chain"},
+                {RPCResult::Type::NUM, "confirmations", "The number of confirmations"},
+                {RPCResult::Type::STR_AMOUNT, "value", "The transaction value in " + CURRENCY_UNIT},
+                {RPCResult::Type::OBJ, "scriptPubKey", "", {
+                    {RPCResult::Type::STR_HEX, "asm", ""},
+                    {RPCResult::Type::STR_HEX, "hex", ""},
+                    {RPCResult::Type::NUM, "reqSigs", "Number of required signatures"},
+                    {RPCResult::Type::STR_HEX, "type", "The type, eg pubkeyhash"},
+                    {RPCResult::Type::ARR, "addresses", "array of bitcoin addresses", {{RPCResult::Type::STR, "address", "bitcoin address"}}},
+                }},
+                {RPCResult::Type::BOOL, "coinbase", "Coinbase or not"},
+            }},
+        },
+        RPCExamples{
             "\nGet unspent transactions\n"
             + HelpExampleCli("listunspent", "") +
             "\nView the details\n"
@@ -2137,59 +2136,64 @@ class CoinsViewScanReserver
 static RPCHelpMan scantxoutset()
 {
     return RPCHelpMan{"scantxoutset",
-                "\nEXPERIMENTAL warning: this call may be removed or changed in future releases.\n"
-                "\nScans the unspent transaction output set for entries that match certain output descriptors.\n"
-                "Examples of output descriptors are:\n"
-                "    addr(<address>)                      Outputs whose scriptPubKey corresponds to the specified address (does not include P2PK)\n"
-                "    raw(<hex script>)                    Outputs whose scriptPubKey equals the specified hex scripts\n"
-                "    combo(<pubkey>)                      P2PK, P2PKH, P2WPKH, and P2SH-P2WPKH outputs for the given pubkey\n"
-                "    pkh(<pubkey>)                        P2PKH outputs for the given pubkey\n"
-                "    sh(multi(<n>,<pubkey>,<pubkey>,...)) P2SH-multisig outputs for the given threshold and pubkeys\n"
-                "\nIn the above, <pubkey> either refers to a fixed public key in hexadecimal notation, or to an xpub/xprv optionally followed by one\n"
-                "or more path elements separated by \"/\", and optionally ending in \"/*\" (unhardened), or \"/*'\" or \"/*h\" (hardened) to specify all\n"
-                "unhardened or hardened child keys.\n"
-                "In the latter case, a range needs to be specified by below if different from 1000.\n"
-                "For more information on output descriptors, see the documentation in the doc/descriptors.md file.\n",
+        "\nEXPERIMENTAL warning: this call may be removed or changed in future releases.\n"
+        "\nScans the unspent transaction output set for entries that match certain output descriptors.\n"
+        "Examples of output descriptors are:\n"
+        "    addr(<address>)                      Outputs whose scriptPubKey corresponds to the specified address (does not include P2PK)\n"
+        "    raw(<hex script>)                    Outputs whose scriptPubKey equals the specified hex scripts\n"
+        "    combo(<pubkey>)                      P2PK, P2PKH, P2WPKH, and P2SH-P2WPKH outputs for the given pubkey\n"
+        "    pkh(<pubkey>)                        P2PKH outputs for the given pubkey\n"
+        "    sh(multi(<n>,<pubkey>,<pubkey>,...)) P2SH-multisig outputs for the given threshold and pubkeys\n"
+        "\nIn the above, <pubkey> either refers to a fixed public key in hexadecimal notation, or to an xpub/xprv optionally followed by one\n"
+        "or more path elements separated by \"/\", and optionally ending in \"/*\" (unhardened), or \"/*'\" or \"/*h\" (hardened) to specify all\n"
+        "unhardened or hardened child keys.\n"
+        "In the latter case, a range needs to be specified by below if different from 1000.\n"
+        "For more information on output descriptors, see the documentation in the doc/descriptors.md file.\n",
+        {
+            {"action", RPCArg::Type::STR, RPCArg::Optional::NO, "The action to execute\n"
+                "\"start\" for starting a scan\n"
+                "\"abort\" for aborting the current scan (returns true when abort was successful)\n"
+                "\"status\" for progress report (in %) of the current scan"},
+            {"scanobjects", RPCArg::Type::ARR, RPCArg::Optional::OMITTED, "Array of scan objects. Required for \"start\" action\n"
+                "Every scan object is either a string descriptor or an object:",
+            {
+                {"descriptor", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "An output descriptor"},
+                {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "An object with output descriptor and metadata",
                 {
-                    {"action", RPCArg::Type::STR, RPCArg::Optional::NO, "The action to execute\n"
-            "                                      \"start\" for starting a scan\n"
-            "                                      \"abort\" for aborting the current scan (returns true when abort was successful)\n"
-            "                                      \"status\" for progress report (in %) of the current scan"},
-                    {"scanobjects", RPCArg::Type::ARR, RPCArg::Optional::OMITTED, "Array of scan objects. Required for \"start\" action\n"
-            "                                  Every scan object is either a string descriptor or an object:",
-                        {
-                            {"descriptor", RPCArg::Type::STR, RPCArg::Optional::OMITTED, "An output descriptor"},
-                            {"", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED, "An object with output descriptor and metadata",
-                                {
-                                    {"desc", RPCArg::Type::STR, RPCArg::Optional::NO, "An output descriptor"},
-                                    {"range", RPCArg::Type::RANGE, /* default */ "1000", "The range of HD chain indexes to explore (either end or [begin,end])"},
-                                },
-                            },
-                        },
+                    {"desc", RPCArg::Type::STR, RPCArg::Optional::NO, "An output descriptor"},
+                    {"range", RPCArg::Type::RANGE, /* default */ "1000", "The range of HD chain indexes to explore (either end or [begin,end])"},
+                }},
+            },
                         "[scanobjects,...]"},
-                },
-                RPCResult{
-                    RPCResult::Type::OBJ, "", "",
+        },
+        {
+            RPCResult{"When action=='abort'", RPCResult::Type::BOOL, "", ""},
+            RPCResult{"When action=='status' and no scan is in progress", RPCResult::Type::NONE, "", ""},
+            RPCResult{"When action=='status' and scan is in progress", RPCResult::Type::OBJ, "", "",
+            {
+                {RPCResult::Type::NUM, "progress", "The scan progress"},
+            }},
+            RPCResult{"When action=='start'", RPCResult::Type::OBJ, "", "", {
+                {RPCResult::Type::BOOL, "success", "Whether the scan was completed"},
+                {RPCResult::Type::NUM, "txouts", "The number of unspent transaction outputs scanned"},
+                {RPCResult::Type::NUM, "height", "The current block height (index)"},
+                {RPCResult::Type::STR_HEX, "bestblock", "The hash of the block at the tip of the chain"},
+                {RPCResult::Type::ARR, "unspents", "",
+                {
+                    {RPCResult::Type::OBJ, "", "",
                     {
-                        {RPCResult::Type::BOOL, "success", "Whether the scan was completed"},
-                        {RPCResult::Type::NUM, "txouts", "The number of unspent transaction outputs scanned"},
-                        {RPCResult::Type::NUM, "height", "The current block height (index)"},
-                        {RPCResult::Type::STR_HEX, "bestblock", "The hash of the block at the tip of the chain"},
-                        {RPCResult::Type::ARR, "unspents", "",
-                            {
-                                {RPCResult::Type::OBJ, "", "",
-                                    {
-                                        {RPCResult::Type::STR_HEX, "txid", "The transaction id"},
-                                        {RPCResult::Type::NUM, "vout", "The vout value"},
-                                        {RPCResult::Type::STR_HEX, "scriptPubKey", "The script key"},
-                                        {RPCResult::Type::STR, "desc", "A specialized descriptor for the matched scriptPubKey"},
-                                        {RPCResult::Type::STR_AMOUNT, "amount", "The total amount in " + CURRENCY_UNIT + " of the unspent output"},
-                                        {RPCResult::Type::NUM, "height", "Height of the unspent transaction output"},
-                                    }},
-                            }},
-                        {RPCResult::Type::STR_AMOUNT, "total_amount", "The total amount of all found unspent outputs in " + CURRENCY_UNIT},
+                        {RPCResult::Type::STR_HEX, "txid", "The transaction id"},
+                        {RPCResult::Type::NUM, "vout", "The vout value"},
+                        {RPCResult::Type::STR_HEX, "scriptPubKey", "The script key"},
+                        {RPCResult::Type::STR, "desc", "A specialized descriptor for the matched scriptPubKey"},
+                        {RPCResult::Type::STR_AMOUNT, "amount", "The total amount in " + CURRENCY_UNIT + " of the unspent output"},
+                        {RPCResult::Type::NUM, "height", "Height of the unspent transaction output"},
                     }},
-                RPCExamples{""},
+                }},
+                {RPCResult::Type::STR_AMOUNT, "total_amount", "The total amount of all found unspent outputs in " + CURRENCY_UNIT},
+            }},
+        },
+        RPCExamples{""},
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VARR});