doc: improve rawtransaction code/test docs

Author: jonatack

src/rpc/rawtransaction.cpp

@@ -39,9 +39,9 @@
 
 #include <univalue.h>
 
-/** High fee rate for sendrawtransaction and testmempoolaccept.
- * By default, transaction with a fee rate higher than this will be rejected by
- * the RPCs. This can be overridden with the maxfeerate argument.
+/** Maximum fee rate for sendrawtransaction and testmempoolaccept.
+ * By default, a transaction with a fee rate higher than this will be rejected
+ * by the RPCs. This can be overridden with the maxfeerate argument.
  */
 static const CFeeRate DEFAULT_MAX_RAW_TX_FEE_RATE{COIN / 10};
 

test/functional/rpc_rawtransaction.py

@@ -438,48 +438,50 @@ def run_test(self):
 
         self.log.info('sendrawtransaction/testmempoolaccept with maxfeerate')
 
-        # Test a transaction with small fee
+        # Test a transaction with a small fee.
         txId = self.nodes[0].sendtoaddress(self.nodes[2].getnewaddress(), 1.0)
         rawTx = self.nodes[0].getrawtransaction(txId, True)
         vout = next(o for o in rawTx['vout'] if o['value'] == Decimal('1.00000000'))
 
         self.sync_all()
         inputs = [{ "txid" : txId, "vout" : vout['n'] }]
-        outputs = { self.nodes[0].getnewaddress() : Decimal("0.99990000") } # 10000 sat fee
+        # Fee 10,000 satoshis, (1 - (10000 sat * 0.00000001 BTC/sat)) = 0.9999
+        outputs = { self.nodes[0].getnewaddress() : Decimal("0.99990000") }
         rawTx = self.nodes[2].createrawtransaction(inputs, outputs)
         rawTxSigned = self.nodes[2].signrawtransactionwithwallet(rawTx)
         assert_equal(rawTxSigned['complete'], True)
-        # 10000 sat fee, ~100 b transaction, fee rate should land around 100 sat/b = 0.00100000 BTC/kB
+        # Fee 10,000 satoshis, ~100 b transaction, fee rate should land around 100 sat/byte = 0.00100000 BTC/kB
         # Thus, testmempoolaccept should reject
         testres = self.nodes[2].testmempoolaccept([rawTxSigned['hex']], 0.00001000)[0]
         assert_equal(testres['allowed'], False)
         assert_equal(testres['reject-reason'], '256: absurdly-high-fee')
         # and sendrawtransaction should throw
         assert_raises_rpc_error(-26, "absurdly-high-fee", self.nodes[2].sendrawtransaction, rawTxSigned['hex'], 0.00001000)
-        # And below calls should both succeed
+        # and the following calls should both succeed
         testres = self.nodes[2].testmempoolaccept(rawtxs=[rawTxSigned['hex']])[0]
         assert_equal(testres['allowed'], True)
         self.nodes[2].sendrawtransaction(hexstring=rawTxSigned['hex'])
 
-        # Test a transaction with large fee
+        # Test a transaction with a large fee.
         txId = self.nodes[0].sendtoaddress(self.nodes[2].getnewaddress(), 1.0)
         rawTx = self.nodes[0].getrawtransaction(txId, True)
         vout = next(o for o in rawTx['vout'] if o['value'] == Decimal('1.00000000'))
 
         self.sync_all()
         inputs = [{ "txid" : txId, "vout" : vout['n'] }]
-        outputs = { self.nodes[0].getnewaddress() : Decimal("0.98000000") } # 2000000 sat fee
+        # Fee 2,000,000 satoshis, (1 - (2000000 sat * 0.00000001 BTC/sat)) = 0.98
+        outputs = { self.nodes[0].getnewaddress() : Decimal("0.98000000") }
         rawTx = self.nodes[2].createrawtransaction(inputs, outputs)
         rawTxSigned = self.nodes[2].signrawtransactionwithwallet(rawTx)
         assert_equal(rawTxSigned['complete'], True)
-        # 2000000 sat fee, ~100 b transaction, fee rate should land around 20000 sat/b = 0.20000000 BTC/kB
+        # Fee 2,000,000 satoshis, ~100 b transaction, fee rate should land around 20,000 sat/byte = 0.20000000 BTC/kB
         # Thus, testmempoolaccept should reject
         testres = self.nodes[2].testmempoolaccept([rawTxSigned['hex']])[0]
         assert_equal(testres['allowed'], False)
         assert_equal(testres['reject-reason'], '256: absurdly-high-fee')
         # and sendrawtransaction should throw
         assert_raises_rpc_error(-26, "absurdly-high-fee", self.nodes[2].sendrawtransaction, rawTxSigned['hex'])
-        # And below calls should both succeed
+        # and the following calls should both succeed
         testres = self.nodes[2].testmempoolaccept(rawtxs=[rawTxSigned['hex']], maxfeerate='0.20000000')[0]
         assert_equal(testres['allowed'], True)
         self.nodes[2].sendrawtransaction(hexstring=rawTxSigned['hex'], maxfeerate='0.20000000')