Integration tests via RPC calls

qa/rpc-tests/wallet.sh runs a three-node -regtest network,
generates a fresh blockchain, and then exercises basic wallet
sending/receiving functionality using command-line RPC.

qa/rpc-tests/util.sh

@@ -0,0 +1,84 @@
+#!/usr/bin/env bash
+
+# Functions used by more than one test
+
+function echoerr {
+  echo "$@" 1>&2;
+}
+
+# Usage: ExtractKey <key> "<json_object_string>"
+# Warning: this will only work for the very-well-behaved
+# JSON produced by bitcoind, do NOT use it to try to
+# parse arbitrary/nested/etc JSON.
+function ExtractKey {
+    echo $2 | tr -d ' "{}\n' | awk -v RS=',' -F: "\$1 ~ /$1/ { print \$2}"
+}
+
+function CreateDataDir {
+  DIR=$1
+  mkdir -p $DIR
+  CONF=$DIR/bitcoin.conf
+  echo "regtest=1" >> $CONF
+  echo "keypool=2" >> $CONF
+  echo "rpcuser=rt" >> $CONF
+  echo "rpcpassword=rt" >> $CONF
+  echo "rpcwait=1" >> $CONF
+  shift
+  while (( "$#" )); do
+      echo $1 >> $CONF
+      shift
+  done
+}
+
+function AssertEqual {
+  if (( $( echo "$1 == $2" | bc ) == 0 ))
+  then
+    echoerr "AssertEqual: $1 != $2"
+    exit 1
+  fi
+}
+
+# CheckBalance -datadir=... amount account minconf
+function CheckBalance {
+  B=$( $CLI $1 getbalance $3 $4 )
+  if (( $( echo "$B == $2" | bc ) == 0 ))
+  then
+    echoerr "bad balance: $B (expected $2)"
+    exit 1
+  fi
+}
+
+# Use: Address <datadir> [account]
+function Address {
+  $CLI $1 getnewaddress $2
+}
+
+# Send from to amount
+function Send {
+  from=$1
+  to=$2
+  amount=$3
+  address=$(Address $to)
+  txid=$( $CLI $from sendtoaddress $address $amount )
+}
+
+# Use: Unspent <datadir> <n'th-last-unspent> <var>
+function Unspent {
+  local r=$( $CLI $1 listunspent | awk -F'[ |:,"]+' "\$2 ~ /$3/ { print \$3 }" | tail -n $2 | head -n 1)
+  echo $r
+}
+
+# Use: CreateTxn1 <datadir> <n'th-last-unspent> <destaddress>
+# produces hex from signrawtransaction
+function CreateTxn1 {
+  TXID=$(Unspent $1 $2 txid)
+  AMOUNT=$(Unspent $1 $2 amount)
+  VOUT=$(Unspent $1 $2 vout)
+  RAWTXN=$( $CLI $1 createrawtransaction "[{\"txid\":\"$TXID\",\"vout\":$VOUT}]" "{\"$3\":$AMOUNT}")
+  ExtractKey hex "$( $CLI $1 signrawtransaction $RAWTXN )"
+}
+
+# Use: SendRawTxn <datadir> <hex_txn_data>
+function SendRawTxn {
+  $CLI $1 sendrawtransaction $2
+}