[TASK] Add Transaction.getBalanceChanges, computed from metadata

2025-11-20 12:15:51 +00:00 · 2014-12-05 18:00:10 -08:00
parent 59017bc0bd
commit 72387873b4
15 changed files with 1267 additions and 20 deletions
--- a/docs/GUIDES.md
+++ b/docs/GUIDES.md
@@ -250,3 +250,11 @@ remote.connect(function() {
  });
 });
 ```
+
+##Transaction Metadata##
+
+The following is a supplement to https://wiki.ripple.com/Ledger_Format#RippleState
+
+The HighNode/LowNode fields in the transaction metadata are deletion hints to allow trustline deletion in constant time. Trustlines for a node are stored in a linked list of pages containing at most 32 trustlines each. A node may have a very large number of trustlines, so if you had to delete a trustline with only the addresses of the two nodes, you would have to iterate through all the pages in each node looking for the trustline that links to the other node. The HighNode/LowNode fields contain pointers to the relevant page so that rippled does not have to iterate through all the pages. If there is only one page, then HighNode/LowNode will be set to a string of zeros.
+
+For more information about what a HighNode and LowNode are, see the Trust Line section in rippled/app/ledger/README.md
--- a/npm-shrinkwrap.json
+++ b/npm-shrinkwrap.json
@@ -4,15 +4,23 @@
  "dependencies": {
    "async": {
      "version": "0.8.0",
-      "from": "async@>=0.8.0 <0.9.0"
+      "from": "async@~0.8.0",
+      "resolved": "https://registry.npmjs.org/async/-/async-0.8.0.tgz"
    },
    "extend": {
      "version": "1.2.1",
-      "from": "extend@>=1.2.1 <1.3.0"
+      "from": "extend@~1.2.1",
+      "resolved": "https://registry.npmjs.org/extend/-/extend-1.2.1.tgz"
+    },
+    "lodash": {
+      "version": "2.4.1",
+      "from": "lodash@~2.4.1",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-2.4.1.tgz"
    },
    "lru-cache": {
      "version": "2.5.0",
-      "from": "lru-cache@>=2.5.0 <2.6.0"
+      "from": "lru-cache@~2.5.0",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-2.5.0.tgz"
    },
    "ripple-wallet-generator": {
      "version": "1.0.1",
@@ -21,7 +29,8 @@
    },
    "superagent": {
      "version": "0.18.2",
-      "from": "superagent@>=0.18.0 <0.19.0",
+      "from": "superagent@^0.18.0",
+      "resolved": "https://registry.npmjs.org/superagent/-/superagent-0.18.2.tgz",
      "dependencies": {
        "qs": {
          "version": "0.6.6",
@@ -55,7 +64,8 @@
        },
        "debug": {
          "version": "1.0.4",
-          "from": "debug@>=1.0.1 <1.1.0",
+          "from": "debug@~1.0.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-1.0.4.tgz",
          "dependencies": {
            "ms": {
              "version": "0.6.2",
@@ -75,8 +85,9 @@
          "resolved": "https://registry.npmjs.org/form-data/-/form-data-0.1.3.tgz",
          "dependencies": {
            "combined-stream": {
-              "version": "0.0.5",
-              "from": "combined-stream@>=0.0.4 <0.1.0",
+              "version": "0.0.7",
+              "from": "combined-stream@~0.0.4",
+              "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-0.0.7.tgz",
              "dependencies": {
                "delayed-stream": {
                  "version": "0.0.5",
@@ -87,17 +98,20 @@
            },
            "async": {
              "version": "0.9.0",
-              "from": "async@>=0.9.0 <0.10.0"
+              "from": "async@~0.9.0",
+              "resolved": "https://registry.npmjs.org/async/-/async-0.9.0.tgz"
            }
          }
        },
        "readable-stream": {
          "version": "1.0.27-1",
          "from": "readable-stream@1.0.27-1",
+          "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-1.0.27-1.tgz",
          "dependencies": {
            "core-util-is": {
              "version": "1.0.1",
-              "from": "core-util-is@>=1.0.0 <1.1.0"
+              "from": "core-util-is@~1.0.0",
+              "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.1.tgz"
            },
            "isarray": {
              "version": "0.0.1",
@@ -106,11 +120,13 @@
            },
            "string_decoder": {
              "version": "0.10.31",
-              "from": "string_decoder@>=0.10.0 <0.11.0"
+              "from": "string_decoder@~0.10.x",
+              "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-0.10.31.tgz"
            },
            "inherits": {
              "version": "2.0.1",
-              "from": "inherits@>=2.0.1 <2.1.0"
+              "from": "inherits@~2.0.1",
+              "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz"
            }
          }
        }
@@ -118,23 +134,28 @@
    },
    "ws": {
      "version": "0.4.32",
-      "from": "ws@>=0.4.31 <0.5.0",
+      "from": "ws@~0.4.31",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-0.4.32.tgz",
      "dependencies": {
        "commander": {
          "version": "2.1.0",
-          "from": "commander@>=2.1.0 <2.2.0"
+          "from": "commander@~2.1.0",
+          "resolved": "https://registry.npmjs.org/commander/-/commander-2.1.0.tgz"
        },
        "nan": {
          "version": "1.0.0",
-          "from": "nan@>=1.0.0 <1.1.0"
+          "from": "nan@~1.0.0",
+          "resolved": "https://registry.npmjs.org/nan/-/nan-1.0.0.tgz"
        },
        "tinycolor": {
          "version": "0.0.1",
-          "from": "tinycolor@>=0.0.0 <1.0.0"
+          "from": "tinycolor@0.x",
+          "resolved": "https://registry.npmjs.org/tinycolor/-/tinycolor-0.0.1.tgz"
        },
        "options": {
          "version": "0.0.6",
-          "from": "options@>=0.0.5"
+          "from": "options@>=0.0.5",
+          "resolved": "https://registry.npmjs.org/options/-/options-0.0.6.tgz"
        }
      }
    }
--- a/package.json
+++ b/package.json
@@ -15,6 +15,7 @@
    "test": "test"
  },
  "dependencies": {
+    "lodash": "~2.4.1",
    "async": "~0.8.0",
    "ws": "~0.4.31",
    "extend": "~1.2.1",
--- a/src/js/ripple/amount.js
+++ b/src/js/ripple/amount.js
@@ -17,6 +17,14 @@ var Currency = require('./currency').Currency;
 // http://docs.oracle.com/javase/1.3/docs/api/java/math/BigInteger.html
 //

+function bignum(x) {
+  return Amount.from_json({value: x.toString()});
+};
+
+function dropsToXrp(drops) {
+  return bignum(drops).divide(1000000).to_text();
+};
+
 function Amount() {
  // Json format:
  //  integer : XRP
@@ -1249,6 +1257,23 @@ Amount.prototype.to_json = function() {
  return result;
 };

+Amount.prototype.toJSON = function() {
+  if (this._is_native) {
+    return {
+      issuer: '',
+      currency: 'XRP',
+      value: dropsToXrp(this.to_text())
+    };
+  } else {
+    return {
+      issuer: this._issuer.to_json(),
+      currency: this._currency.has_interest() ?
+        this._currency.to_hex() : this._currency.to_json().toString(),
+      value: this.to_text()
+    };
+  }
+};
+
 Amount.prototype.to_text_full = function(opts) {
  return this._value instanceof BigInteger
    ? this._is_native
--- a/src/js/ripple/meta.js
+++ b/src/js/ripple/meta.js
@@ -1,3 +1,4 @@
+var _ = require('lodash');
 var extend  = require('extend');
 var utils   = require('./utils');
 var UInt160 = require('./uint160').UInt160;
@@ -11,8 +12,6 @@ var Amount  = require('./amount').Amount;
 */

 function Meta(data) {
-  var self = this;
-
  this.nodes = [ ];

  if (typeof data !== 'object') {
@@ -238,4 +237,136 @@ Meta.prototype.getAffectedBooks = function() {
  return this._affectedBooks;
 };

+
+// TODO: migrate to external bignum library
+function bignum(x) {
+  return Amount.from_json({value: x.toString()});
+};
+
+// Merge balance changes that have the same account, issuer, and currency
+// by summing them together
+function mergeBalanceChanges(balanceChanges) {
+  var grouped = _.groupBy(balanceChanges, function(change) {
+    return (change.address + '-' +
+            change.balance_change.issuer().to_json().toString() + '-' +
+            change.balance_change.currency().to_json().toString());
+  });
+  return _.compact(Object.keys(grouped).map(function(key) {
+    var group = grouped[key];
+    var valueSum = bignum(0);
+    group.forEach(function(change) {
+      valueSum = valueSum.add(bignum(change.balance_change.to_text()));
+    });
+    if (valueSum.is_zero()) {
+      return null;      // do not report balance change if there was no change
+    }
+    var currency = group[0].balance_change.currency().to_json();
+    var balanceChange = currency === 'XRP' ?
+      Amount.from_json(valueSum.to_text()) :
+      Amount.from_json({
+        issuer:  group[0].balance_change.issuer().to_json(),
+        currency: currency,
+        value: valueSum.to_text()
+      });
+    return {
+      address: group[0].address,
+      balance_change: balanceChange
+    };
+  }));
+};
+
+function parseAccountRootBalanceChange(node, address) {
+  if (!_.isEmpty(node.fieldsNew)) {
+    return {
+      address: node.fieldsNew.Account,
+      balance_change: Amount.from_json(node.fieldsNew.Balance)
+    };
+  } else if (!_.isEmpty(node.fieldsFinal)) {
+    var finalBal = bignum(node.fieldsFinal.Balance);
+    var prevBal = (typeof node.fieldsPrev.Balance === 'string') ?
+      bignum(node.fieldsPrev.Balance) : bignum(0);
+
+    return {
+      address: node.fieldsFinal.Account,
+      balance_change: Amount.from_json(finalBal.subtract(prevBal).to_text())
+    };
+  }
+
+  return null;
+};
+
+function isHighNodeIssuer(trustBalFinal, trustBalPrev, trustHigh, trustLow) {
+  if (trustBalFinal.is_positive()) {
+    return true;
+  } else if (trustBalFinal.is_negative()) {
+    return false;
+  } else if (trustBalPrev.is_positive()) {
+    return true;
+  } else if (trustBalPrev.is_negative()) {
+    return false;
+  } else if (trustLow.is_zero() && trustHigh.is_positive()) {
+    return false;    // high node cannot issue
+  } else if (trustHigh.is_zero() && trustLow.is_positive()) {
+    return true;     // low node cannot issue
+  } else {
+    return false;    // totally arbitrary
+  }
+};
+
+function parseTrustlineBalanceChange(node, address) {
+  if (!_.isEmpty(node.fieldsFinal)) {
+    if (!(node.fieldsPrev.Balance)) {
+      return null;    // setting a trustline limit, no balance change
+    }
+  }
+  var finalFields = _.isEmpty(node.fieldsNew) ?
+    node.fieldsFinal : node.fieldsNew;
+  var trustHighIssuer = finalFields.HighLimit.issuer;
+  var trustLowIssuer = finalFields.LowLimit.issuer;
+  if (address !== trustLowIssuer && address !== trustHighIssuer) {
+    return null;
+  }
+  var trustHigh = bignum(finalFields.HighLimit.value);
+  var trustLow = bignum(finalFields.LowLimit.value);
+  var trustBalFinal = bignum(finalFields.Balance.value);
+  var trustBalPrev = node.fieldsPrev.Balance ?
+    bignum(node.fieldsPrev.Balance.value) : bignum(0);
+  var trustBalChange = trustBalFinal.subtract(trustBalPrev);
+  var issuer = isHighNodeIssuer(trustBalFinal, trustBalPrev, trustHigh,
+    trustLow) ? trustHighIssuer : trustLowIssuer;
+  var balanceChange = (address === trustHighIssuer) ?
+    trustBalChange.negate() : trustBalChange;
+
+  return {
+    address: address,
+    balance_change: Amount.from_json({
+      value: balanceChange.to_text(),
+      currency: finalFields.Balance.currency,
+      issuer: issuer
+    })
+  };
+};
+
+function parseTrustlineBalanceChanges(node) {
+  var fields = _.isEmpty(node.fieldsNew) ? node.fieldsFinal : node.fieldsNew;
+  return [parseTrustlineBalanceChange(node, fields.HighLimit.issuer),
+          parseTrustlineBalanceChange(node, fields.LowLimit.issuer)];
+};
+
+Meta.prototype.parseBalanceChanges = function() {
+  var balanceChanges = this.nodes.map(function(node) {
+    if (node.entryType === 'AccountRoot') {
+      // Look for XRP balance change in AccountRoot node
+      return [parseAccountRootBalanceChange(node)];
+    } else if (node.entryType === 'RippleState') {
+      // Look for trustline balance change in RippleState node
+      return parseTrustlineBalanceChanges(node);
+    } else {
+      return [ ];
+    }
+  });
+
+  return mergeBalanceChanges(_.compact(_.flatten(balanceChanges)));
+};
+
 exports.Meta = Meta;
--- a/src/js/ripple/transaction.js
+++ b/src/js/ripple/transaction.js
@@ -1,5 +1,4 @@
 var util             = require('util');
-var assert           = require('assert');
 var EventEmitter     = require('events').EventEmitter;
 var utils            = require('./utils');
 var sjcl             = require('./utils').sjcl;
@@ -12,6 +11,7 @@ var RippleError      = require('./rippleerror').RippleError;
 var hashprefixes     = require('./hashprefixes');
 var config           = require('./config');
 var log              = require('./log').internal.sub('transaction');
+var Meta             = require('./meta').Meta;

 /**
 * @constructor Transaction
@@ -48,6 +48,7 @@ function Transaction(remote) {
  this.attempts = 0;
  this.submissions = 0;
  this.responses = 0;
+  this.mmeta = void(0);

  this.once('success', function(message) {
    // Transaction definitively succeeded
@@ -214,6 +215,10 @@ Transaction.prototype.setState = function(state) {
 Transaction.prototype.finalize = function(message) {
  this.finalized = true;

+  if (typeof message.metadata === 'object') {
+    this.mmeta = new Meta(message.metadata);
+  }
+
  if (this.result) {
    this.result.ledger_index = message.ledger_index;
    this.result.ledger_hash  = message.ledger_hash;
@@ -909,7 +914,7 @@ Transaction.prototype.accountSet = function(src, set_flag, clear_flag) {
    return (typeof flag === 'number')
    ?  flag
    : (SetClearFlags[flag] || SetClearFlags['asf' + flag]);
-  };
+  }

  if (set_flag && (set_flag = prepareFlag(set_flag))) {
    this.tx_json.SetFlag = set_flag;
@@ -1198,6 +1203,13 @@ Transaction.prototype.summary = function() {
  return result;
 };

+Transaction.prototype.getBalanceChanges = function() {
+  if (!this.finalized || this.mmeta === void(0)) {
+    return [ ];
+  }
+  return this.mmeta.parseBalanceChanges();
+};
+
 exports.Transaction = Transaction;

 // vim:sw=2:sts=2:ts=8:et
--- a/test/fixtures/payment-iou-destination-no-balance.json
+++ b/test/fixtures/payment-iou-destination-no-balance.json
@@ -0,0 +1,123 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "1B549453005A924A4EEF6DA9E1BA7D8D1E51D7B685CE8DE072667321FBA792C8",
+  "ledger_index": 10425094,
+  "status": "closed",
+  "type": "transaction",
+  "validated": true,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.535330905250352"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+              "value": "1000000000"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "2F323020B4288ACD4066CC64C89DAD2E4D5DFC2D44571942A51C005BF79D6E25",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.545330905250352"
+            }
+          },
+          "PreviousTxnID": "CEB7B6040C2989B9849C8D7E49F710457EDDE1D95ECDF1E298FD30CF2AC5BE11",
+          "PreviousTxnLgrSeq": 10424776
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0.01"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "1000000000"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "AAE13AF5192EFBFD49A8EEE5869595563FEB73228C0B38FED9CC3D20EE74F399",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0"
+            }
+          },
+          "PreviousTxnID": "A788447CF5FD7108CBF49416E2335F95ED3F5A9FC016686C8F9EFB34BBEA613A",
+          "PreviousTxnLgrSeq": 10425088
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+            "Balance": "239807992",
+            "Flags": 0,
+            "OwnerCount": 1,
+            "Sequence": 17
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "E9A39B0BA8703D5FFD05D9EAD01EE6C0E7A15CF33C2C6B7269107BD2BD535818",
+          "PreviousFields": {
+            "Balance": "239819992",
+            "Sequence": 16
+          },
+          "PreviousTxnID": "3109F5A0F891CCA20B4D891EB7437973F40A7664C5176092EB2E5C0A949992AD",
+          "PreviousTxnLgrSeq": 10424942
+        }
+      }
+    ],
+    "TransactionIndex": 3,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "tx_json": {
+    "Account": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+    "Amount": {
+      "currency": "USD",
+      "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+      "value": "0.01"
+    },
+    "Destination": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10425102,
+    "Sequence": 16,
+    "SigningPubKey": "03F16A52EBDCA6EBF5D99828E1E6918C64D45E6F136476A8F4757512FE553D18F0",
+    "TransactionType": "Payment",
+    "TxnSignature": "3044022017DC45606103FF2CCE5D63E340D1E2B302BE16C206673B99712058CA0DBD2CC5022074A19CF5AF9CDFCEC821650A4C22E83E49E14956E1F2A094181E8E14F6881200",
+    "date": 471494760,
+    "hash": "D038C9D95926EACAA9FBDF3E6CA0675ACF1700B3CE13FF4CA52B463B58860BBA"
+  }
+}
--- a/test/fixtures/payment-iou-spend-full-balance.json
+++ b/test/fixtures/payment-iou-spend-full-balance.json
@@ -0,0 +1,124 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "605F02CC71269E0C3253FC582503D0A69533DF9E744F1613CB132A67261527F2",
+  "ledger_index": 10458307,
+  "status": "closed",
+  "type": "transaction",
+  "validated": true,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.545330905250352"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+              "value": "1000000000"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "2F323020B4288ACD4066CC64C89DAD2E4D5DFC2D44571942A51C005BF79D6E25",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.345330905250352"
+            }
+          },
+          "PreviousTxnID": "24525F80080EAC8857F1A29A47AEF23FD2B0A52DAF7DC3900A4E31831187FCB1",
+          "PreviousTxnLgrSeq": 10443886
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "1000000000"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "AAE13AF5192EFBFD49A8EEE5869595563FEB73228C0B38FED9CC3D20EE74F399",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0.2"
+            }
+          },
+          "PreviousTxnID": "24525F80080EAC8857F1A29A47AEF23FD2B0A52DAF7DC3900A4E31831187FCB1",
+          "PreviousTxnLgrSeq": 10443886
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "Balance": "99976002",
+            "Flags": 0,
+            "OwnerCount": 1,
+            "Sequence": 3
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "C24354B286600B8F28E51233B4AC41A3B4DDD0FDC9BCF96BB171573F6B40A4AE",
+          "PreviousFields": {
+            "Balance": "99988002",
+            "Sequence": 2
+          },
+          "PreviousTxnID": "A788447CF5FD7108CBF49416E2335F95ED3F5A9FC016686C8F9EFB34BBEA613A",
+          "PreviousTxnLgrSeq": 10425088
+        }
+      }
+    ],
+    "TransactionIndex": 3,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "tx_json": {
+    "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Amount": {
+      "currency": "USD",
+      "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+      "value": "0.2"
+    },
+    "Destination": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10458314,
+    "Sequence": 2,
+    "SigningPubKey": "039371D0465097AC8F9C02EB60D5599AAD08AADBD623D6D40D642CF2D7C0481B83",
+    "TransactionType": "Payment",
+    "TxnSignature": "304502210097A62D87FF08A050F1832B974F06FB4F0C83F6661CC916AE190A439C8DB3863202204CD27C5C6A9067BA5A1DA9BB940FDF3F7C6B073225911E567B1E37E9C29E99D4",
+    "date": 471639670,
+    "hash": "5AC7632779C3AE649236F728C2C6811D7ADDE6CCC5018B8754C6EB953FCB1BC5"
+  }
+}
+
--- a/test/fixtures/payment-iou.json
+++ b/test/fixtures/payment-iou.json
@@ -0,0 +1,123 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "F3F1416BF2E813396AB01FAA38E9F1023AC4D2368D94B0D52B2BC603CEEC01C3",
+  "ledger_index": 10459371,
+  "status": "closed",
+  "type": "transaction",
+  "validated": true,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.525330905250352"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+              "value": "1000000000"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "2F323020B4288ACD4066CC64C89DAD2E4D5DFC2D44571942A51C005BF79D6E25",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.535330905250352"
+            }
+          },
+          "PreviousTxnID": "DC061E6F47B1B6E9A496A31B1AF87194B4CB24B2EBF8A59F35E31E12509238BD",
+          "PreviousTxnLgrSeq": 10459364
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0.02"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "1000000000"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "AAE13AF5192EFBFD49A8EEE5869595563FEB73228C0B38FED9CC3D20EE74F399",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0.01"
+            }
+          },
+          "PreviousTxnID": "DC061E6F47B1B6E9A496A31B1AF87194B4CB24B2EBF8A59F35E31E12509238BD",
+          "PreviousTxnLgrSeq": 10459364
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+            "Balance": "239555992",
+            "Flags": 0,
+            "OwnerCount": 1,
+            "Sequence": 38
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "E9A39B0BA8703D5FFD05D9EAD01EE6C0E7A15CF33C2C6B7269107BD2BD535818",
+          "PreviousFields": {
+            "Balance": "239567992",
+            "Sequence": 37
+          },
+          "PreviousTxnID": "DC061E6F47B1B6E9A496A31B1AF87194B4CB24B2EBF8A59F35E31E12509238BD",
+          "PreviousTxnLgrSeq": 10459364
+        }
+      }
+    ],
+    "TransactionIndex": 2,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "tx_json": {
+    "Account": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+    "Amount": {
+      "currency": "USD",
+      "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+      "value": "0.01"
+    },
+    "Destination": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10459379,
+    "Sequence": 37,
+    "SigningPubKey": "03F16A52EBDCA6EBF5D99828E1E6918C64D45E6F136476A8F4757512FE553D18F0",
+    "TransactionType": "Payment",
+    "TxnSignature": "3044022031D6AB55CDFD17E06DA0BAD6D6B7DC9B5CA8FFF50405F2FCD3ED8D3893B1835E02200524CC1E7D70AE3F00C9F94405C55EE179C363F534905168AE8B5BA01CF568A0",
+    "date": 471644150,
+    "hash": "34671C179737CC89E0F8BBAA83C313885ED1733488FC0F3088BAE16A3D9A5B1B"
+  }
+}
--- a/test/fixtures/payment-xrp-create-account.json
+++ b/test/fixtures/payment-xrp-create-account.json
@@ -0,0 +1,60 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "5FA9BBBE9EF6CE4BF9BB56CC3A70106C1475EA4C02EDE26651710FAA46E81F60",
+  "ledger_index": 10424084,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "CreatedNode": {
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "C24354B286600B8F28E51233B4AC41A3B4DDD0FDC9BCF96BB171573F6B40A4AE",
+          "NewFields": {
+            "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "Balance": "100000000",
+            "Sequence": 1
+          }
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+            "Balance": "339903994",
+            "Flags": 0,
+            "OwnerCount": 0,
+            "Sequence": 9
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "E9A39B0BA8703D5FFD05D9EAD01EE6C0E7A15CF33C2C6B7269107BD2BD535818",
+          "PreviousFields": {
+            "Balance": "439915994",
+            "Sequence": 8
+          },
+          "PreviousTxnID": "0E6CF1A13C6A804BE50B08C1D0446C7405D8461254CC6B62337CA9FEA4DF13EC",
+          "PreviousTxnLgrSeq": 10424064
+        }
+      }
+    ],
+    "TransactionIndex": 3,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "status": "closed",
+  "transaction": {
+    "Account": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+    "Amount": "100000000",
+    "Destination": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10424091,
+    "Sequence": 8,
+    "SigningPubKey": "03F16A52EBDCA6EBF5D99828E1E6918C64D45E6F136476A8F4757512FE553D18F0",
+    "TransactionType": "Payment",
+    "TxnSignature": "304402207676FE35FF0D01E01F13531760658ADECC493181A4EF618A970E4C209FC989C102206660147F17B46469864E9E10152844C4DA62363DB70B5F610E6DAEA87A6781A9",
+    "date": 471490400,
+    "hash": "43CAAC76C95358CA2F84EA8BF5BFC327B90B21039A3C69EC4EAC7FEDC54CDB9F"
+  },
+  "type": "transaction",
+  "validated": true
+}
--- a/test/fixtures/trustline-create.json
+++ b/test/fixtures/trustline-create.json
@@ -0,0 +1,109 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "CA4C25E271FDB00836A091E8073F6692784BEB116B33675533F9511B17FC2B72",
+  "ledger_index": 10483144,
+  "status": "closed",
+  "type": "transaction",
+  "validated": true,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Flags": 0,
+            "IndexPrevious": "00000000000001F1",
+            "Owner": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+            "RootIndex": "6319526CE8F9A8A44D7A870A89DC1B4AD848AA4F066FCB5390A9A268F6E16AEA"
+          },
+          "LedgerEntryType": "DirectoryNode",
+          "LedgerIndex": "58E06162628C5E2292DA172A97573FA5613C4A223810686428BF8431B3D67C58"
+        }
+      },
+      {
+        "CreatedNode": {
+          "LedgerEntryType": "DirectoryNode",
+          "LedgerIndex": "84C8F98961F2F10CB1B5C4FB649C18B05A9D3FC20C3A78B75C86CD30D7EAC39C",
+          "NewFields": {
+            "Owner": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "RootIndex": "84C8F98961F2F10CB1B5C4FB649C18B05A9D3FC20C3A78B75C86CD30D7EAC39C"
+          }
+        }
+      },
+      {
+        "ModifiedNode": {
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "A3C1529122C3DBD6C96B9DF009FF4896023FE6B4E05A508B1E81F3DCD9A6274B",
+          "PreviousTxnID": "CA4BD65D1E29552B17041B219105E1BC0FE00837C798DE9F9E2EA670097ACE33",
+          "PreviousTxnLgrSeq": 10483128
+        }
+      },
+      {
+        "CreatedNode": {
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "AAE13AF5192EFBFD49A8EEE5869595563FEB73228C0B38FED9CC3D20EE74F399",
+          "NewFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0"
+            },
+            "Flags": 65536,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001F2",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "100"
+            }
+          }
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "Balance": "99740302",
+            "Flags": 0,
+            "OwnerCount": 1,
+            "Sequence": 23
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "C24354B286600B8F28E51233B4AC41A3B4DDD0FDC9BCF96BB171573F6B40A4AE",
+          "PreviousFields": {
+            "Balance": "99752302",
+            "OwnerCount": 0,
+            "Sequence": 22
+          },
+          "PreviousTxnID": "8A3F4CA1D349B4BE896DFDED6B6D0F0DCA4FCA75E082C30A4175813DDB9BCDA6",
+          "PreviousTxnLgrSeq": 10482869
+        }
+      }
+    ],
+    "TransactionIndex": 10,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "tx_json": {
+    "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10483152,
+    "LimitAmount": {
+      "currency": "USD",
+      "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+      "value": "100"
+    },
+    "Sequence": 22,
+    "SigningPubKey": "039371D0465097AC8F9C02EB60D5599AAD08AADBD623D6D40D642CF2D7C0481B83",
+    "TransactionType": "TrustSet",
+    "TxnSignature": "3044022048862FBF688AFFA81E8A08DB08C2559BB5D7E935B5E4597EE6ADF2E901BC9A6402200B7CDBAD2001CB9797AD56E22D9DA1C23F7F5DC1BB8DB22F013DEE78EAC46BE4",
+    "date": 471748760,
+    "hash": "8375C1ED96BB4DD66FD697F34755F9B03DB62CD098627B834028728670CF93EF"
+  }
+}
+
--- a/test/fixtures/trustline-delete.json
+++ b/test/fixtures/trustline-delete.json
@@ -0,0 +1,157 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "BFD12A293442E8C083A98092C7A8A199A3732B2360643E40BB8704DE3DF8EA5E",
+  "ledger_index": 10482869,
+  "status": "closed",
+  "type": "transaction",
+  "validated": true,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.545330905250352"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+              "value": "1000000000"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "2F323020B4288ACD4066CC64C89DAD2E4D5DFC2D44571942A51C005BF79D6E25",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "1.525330905250352"
+            }
+          },
+          "PreviousTxnID": "D1B2B5508585E1BB48E1D76629C59F6368AAB9568457D058486DCC4DCAECCE30",
+          "PreviousTxnLgrSeq": 10482855
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Flags": 0,
+            "IndexPrevious": "00000000000001F1",
+            "Owner": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+            "RootIndex": "6319526CE8F9A8A44D7A870A89DC1B4AD848AA4F066FCB5390A9A268F6E16AEA"
+          },
+          "LedgerEntryType": "DirectoryNode",
+          "LedgerIndex": "58E06162628C5E2292DA172A97573FA5613C4A223810686428BF8431B3D67C58"
+        }
+      },
+      {
+        "DeletedNode": {
+          "FinalFields": {
+            "Flags": 0,
+            "Owner": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "RootIndex": "84C8F98961F2F10CB1B5C4FB649C18B05A9D3FC20C3A78B75C86CD30D7EAC39C"
+          },
+          "LedgerEntryType": "DirectoryNode",
+          "LedgerIndex": "84C8F98961F2F10CB1B5C4FB649C18B05A9D3FC20C3A78B75C86CD30D7EAC39C"
+        }
+      },
+      {
+        "ModifiedNode": {
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "A3C1529122C3DBD6C96B9DF009FF4896023FE6B4E05A508B1E81F3DCD9A6274B",
+          "PreviousTxnID": "758E69A2A2F5E7713ACCA70DC82DD89D7B45B9E020A7E19B9312F0C49A8834BA",
+          "PreviousTxnLgrSeq": 10482869
+        }
+      },
+      {
+        "DeletedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0"
+            },
+            "Flags": 0,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001F2",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "0"
+            },
+            "LowNode": "0000000000000000",
+            "PreviousTxnID": "CA491349DAF4D4EB1E5D2EF1DD4BBC84640C22B4C94C3C9AD40B190151A7878B",
+            "PreviousTxnLgrSeq": 10482862
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "AAE13AF5192EFBFD49A8EEE5869595563FEB73228C0B38FED9CC3D20EE74F399",
+          "PreviousFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0.02"
+            },
+            "Flags": 65536
+          }
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "Balance": "99752302",
+            "Flags": 0,
+            "OwnerCount": 0,
+            "Sequence": 22
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "C24354B286600B8F28E51233B4AC41A3B4DDD0FDC9BCF96BB171573F6B40A4AE",
+          "PreviousFields": {
+            "Balance": "99764302",
+            "OwnerCount": 1,
+            "Sequence": 21
+          },
+          "PreviousTxnID": "CA491349DAF4D4EB1E5D2EF1DD4BBC84640C22B4C94C3C9AD40B190151A7878B",
+          "PreviousTxnLgrSeq": 10482862
+        }
+      }
+    ],
+    "TransactionIndex": 9,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "tx_json": {
+    "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Amount": {
+      "currency": "USD",
+      "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+      "value": "0.02"
+    },
+    "Destination": "rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10482877,
+    "Sequence": 21,
+    "SigningPubKey": "039371D0465097AC8F9C02EB60D5599AAD08AADBD623D6D40D642CF2D7C0481B83",
+    "TransactionType": "Payment",
+    "TxnSignature": "3045022100E718DDE0149F89CF58FAD1847ED7AD9D61D833E07969A71FA7918D2F6D414AAE022041226ADCB68C2B64CA37AAB4C268922F2EE09DFBF8B234B282E9104643C6351D",
+    "date": 471747550,
+    "hash": "8A3F4CA1D349B4BE896DFDED6B6D0F0DCA4FCA75E082C30A4175813DDB9BCDA6"
+  }
+}
+
--- a/test/fixtures/trustline-set-limit-to-zero.json
+++ b/test/fixtures/trustline-set-limit-to-zero.json
@@ -0,0 +1,87 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "BCA3403873155ECFEB616ED9923D94430CB26EA7206CBCC4F86EACE47B33F950",
+  "ledger_index": 10460919,
+  "status": "closed",
+  "type": "transaction",
+  "validated": true,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0.02"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "0"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "AAE13AF5192EFBFD49A8EEE5869595563FEB73228C0B38FED9CC3D20EE74F399",
+          "PreviousFields": {
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "100"
+            }
+          },
+          "PreviousTxnID": "1BBAC938211E7C2B5A0DD00153557E0A47B38F93AF0F1831C4ECE0E6387B8B96",
+          "PreviousTxnLgrSeq": 10460914
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "Balance": "99940002",
+            "Flags": 0,
+            "OwnerCount": 1,
+            "Sequence": 6
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "C24354B286600B8F28E51233B4AC41A3B4DDD0FDC9BCF96BB171573F6B40A4AE",
+          "PreviousFields": {
+            "Balance": "99952002",
+            "Sequence": 5
+          },
+          "PreviousTxnID": "1BBAC938211E7C2B5A0DD00153557E0A47B38F93AF0F1831C4ECE0E6387B8B96",
+          "PreviousTxnLgrSeq": 10460914
+        }
+      }
+    ],
+    "TransactionIndex": 8,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "tx_json": {
+    "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10460926,
+    "LimitAmount": {
+      "currency": "USD",
+      "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+      "value": "0"
+    },
+    "Sequence": 5,
+    "SigningPubKey": "039371D0465097AC8F9C02EB60D5599AAD08AADBD623D6D40D642CF2D7C0481B83",
+    "TransactionType": "TrustSet",
+    "TxnSignature": "3045022100CAF0DD8A64B68CC9CD44166A381FE07B69AAC5219BB3E90D5A2BD73FB9919DBA022071BE14E0E8ABB0B1841A7A4D1A983C8AC32CFA0E7C9A45FA3565AE5477C076A8",
+    "date": 471650760,
+    "hash": "B836ADBA4D77638C5F8C99B5FC0FC6A92D5F82FF3C90759F44773835BAD2AB86"
+  }
+}
--- a/test/fixtures/trustline-set-limit.json
+++ b/test/fixtures/trustline-set-limit.json
@@ -0,0 +1,88 @@
+{
+  "engine_result": "tesSUCCESS",
+  "engine_result_code": 0,
+  "engine_result_message": "The transaction was applied.",
+  "ledger_hash": "BB1814E087367EB56D7EBF0DB99481291894A53FF8B155511C6CC45D57F42E27",
+  "ledger_index": 10479523,
+  "status": "closed",
+  "type": "transaction",
+  "validated": true,
+  "metadata": {
+    "AffectedNodes": [
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Balance": {
+              "currency": "USD",
+              "issuer": "rrrrrrrrrrrrrrrrrrrrBZbvji",
+              "value": "0.02"
+            },
+            "Flags": 1114112,
+            "HighLimit": {
+              "currency": "USD",
+              "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+              "value": "0"
+            },
+            "HighNode": "00000000000001E8",
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "200"
+            },
+            "LowNode": "0000000000000000"
+          },
+          "LedgerEntryType": "RippleState",
+          "LedgerIndex": "AAE13AF5192EFBFD49A8EEE5869595563FEB73228C0B38FED9CC3D20EE74F399",
+          "PreviousFields": {
+            "LowLimit": {
+              "currency": "USD",
+              "issuer": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+              "value": "100"
+            }
+          },
+          "PreviousTxnID": "A9A654F03855FEBD714E49B2C190A62C310081339AA0AA49C38F0B734E81C173",
+          "PreviousTxnLgrSeq": 10479514
+        }
+      },
+      {
+        "ModifiedNode": {
+          "FinalFields": {
+            "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+            "Balance": "99884302",
+            "Flags": 0,
+            "OwnerCount": 1,
+            "Sequence": 11
+          },
+          "LedgerEntryType": "AccountRoot",
+          "LedgerIndex": "C24354B286600B8F28E51233B4AC41A3B4DDD0FDC9BCF96BB171573F6B40A4AE",
+          "PreviousFields": {
+            "Balance": "99896302",
+            "Sequence": 10
+          },
+          "PreviousTxnID": "BD850F01540CE35B68C1125E2055BBFEEF961D65AEFBC0CE39CF814685144117",
+          "PreviousTxnLgrSeq": 10479508
+        }
+      }
+    ],
+    "TransactionIndex": 10,
+    "TransactionResult": "tesSUCCESS"
+  },
+  "tx_json": {
+    "Account": "rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K",
+    "Fee": "12000",
+    "Flags": 2147483648,
+    "LastLedgerSequence": 10479530,
+    "LimitAmount": {
+      "currency": "USD",
+      "issuer": "rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q",
+      "value": "200"
+    },
+    "Sequence": 10,
+    "SigningPubKey": "039371D0465097AC8F9C02EB60D5599AAD08AADBD623D6D40D642CF2D7C0481B83",
+    "TransactionType": "TrustSet",
+    "TxnSignature": "304502210088A7B69070516F1456AE93CC7189C213E60F1E5276F0FFEB64419CFD3A75FDBA02202E852593523240D5BD59B4DF3FAC97E112F75DF712B07E9C9FC64D824E2E0CB2",
+    "date": 471732720,
+    "hash": "9F54793122AD0CF1552A4E76991CB481E6FAD467176976500E11EA76CAC9D9EA"
+  }
+}
+
--- a/test/metadata-test.js
+++ b/test/metadata-test.js
@@ -0,0 +1,178 @@
+var assert = require('assert');
+var fs = require('fs');
+var utils  = require('./testutils');
+var Meta = utils.load_module('meta').Meta;
+
+// Pay 100 XRP from rKmB to rLDY to create rLDY account
+var createAccountBalanceChanges = [
+  { address: 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K',
+    balance_change: {
+      value: '100',
+      currency: 'XRP',
+      issuer: ''
+    }
+  },
+  { address: 'rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc',
+    balance_change: {
+      value: '-100.012',
+      currency: 'XRP',
+      issuer: ''
+    },
+  }
+];
+
+// Pay 0.01 USD from rKmB to rLDY where rLDY starts with no USD
+var usdFirstPaymentBalanceChanges = [
+  { address: 'rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc',
+    balance_change: {
+      value: '-0.01',
+      currency: 'USD',
+      issuer: 'rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q'
+    }
+  },
+  { address: 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K',
+    balance_change: {
+      value: '0.01',
+      currency: 'USD',
+      issuer: 'rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q'
+    }
+  },
+  { address: 'rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc',
+    balance_change: {
+      value: '-0.012',
+      currency: 'XRP',
+      issuer: ''
+    }
+  }
+];
+
+// Pay 0.2 USD from rLDY to rKmB where rLDY starts with 0.2 USD
+var usdFullPaymentBalanceChanges = [
+  { address: 'rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc',
+    balance_change: {
+      value: '0.2',
+      currency: 'USD',
+      issuer: 'rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q'
+    }
+  },
+  { address: 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K',
+    balance_change: {
+      value: '-0.2',
+      currency: 'USD',
+      issuer: 'rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q'
+    }
+  },
+  { address: 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K',
+    balance_change: {
+      value: '-0.012',
+      currency: 'XRP',
+      issuer: ''
+    }
+  }
+];
+
+// Pay 0.01 USD from rKmB to rLDY where rLDY starts with 0.01 USD
+var usdPaymentBalanceChanges = usdFirstPaymentBalanceChanges;
+
+// Set trust limit to 200 USD on rLDY when it has a trust limit of 100 USD
+// and has a balance of 0.02 USD
+var setTrustlineBalanceChanges = [
+  {
+    address: 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K',
+    balance_change: {
+      value: '-0.012',
+      currency: 'XRP',
+      issuer: ''
+    }
+  }
+];
+
+// Set trust limit to 100 USD on rLDY when it has no trustline
+var createTrustlineBalanceChanges = setTrustlineBalanceChanges;
+
+// Pay 0.02 USD from rLDY to rKmB when rLDY has a trust limit of 0
+// for USD, but still has a balance of 0.02 USD; which closes the trustline
+var deleteTrustlineBalanceChanges = [
+    {
+      address: 'rKmBGxocj9Abgy25J51Mk1iqFzW9aVF9Tc',
+      balance_change: {
+        value: '0.02',
+        currency: 'USD',
+        issuer: 'rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q'
+      }
+    },
+    {
+      address: 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K',
+      balance_change: {
+        value: '-0.02',
+        currency: 'USD',
+        issuer: 'rMwjYedjc7qqtKYVLiAccJSmCwih4LnE2q'
+      }
+    },
+    {
+      address: 'rLDYrujdKUfVx28T9vRDAbyJ7G2WVXKo4K',
+      balance_change: {
+        value: '-0.012',
+        currency: 'XRP',
+        issuer: ''
+      }
+    }
+];
+
+// Set trust limit to zero on rLDY when it has a balance of 0.02 USD
+var removeTrustBalanceChanges = setTrustlineBalanceChanges;
+
+
+function loadFixture(filename) {
+  var path = __dirname + '/fixtures/' + filename;
+  return JSON.parse(fs.readFileSync(path));
+}
+
+function parseBalanceChanges(metadata) {
+  var meta = new Meta(metadata);
+  return JSON.parse(JSON.stringify(meta.parseBalanceChanges()));
+}
+
+describe('parseBalanceChanges', function() {
+  it('XRP create account', function() {
+    var paymentResponse = loadFixture('payment-xrp-create-account.json');
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, createAccountBalanceChanges);
+  });
+  it('USD payment to account with no USD', function() {
+    var filename = 'payment-iou-destination-no-balance.json';
+    var paymentResponse = loadFixture(filename);
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, usdFirstPaymentBalanceChanges);
+  });
+  it('USD payment of all USD in source account', function() {
+    var paymentResponse = loadFixture('payment-iou-spend-full-balance.json');
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, usdFullPaymentBalanceChanges);
+  });
+  it('USD payment to account with USD', function() {
+    var paymentResponse = loadFixture('payment-iou.json');
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, usdPaymentBalanceChanges);
+  });
+  it('Set trust limit to 0 with balance remaining', function() {
+    var paymentResponse = loadFixture('trustline-set-limit-to-zero.json');
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, removeTrustBalanceChanges);
+  });
+  it('Create trustline', function() {
+    var paymentResponse = loadFixture('trustline-create.json');
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, createTrustlineBalanceChanges);
+  });
+  it('Set trustline', function() {
+    var paymentResponse = loadFixture('trustline-set-limit.json');
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, setTrustlineBalanceChanges);
+  });
+  it('Delete trustline', function() {
+    var paymentResponse = loadFixture('trustline-delete.json');
+    var result = parseBalanceChanges(paymentResponse.metadata);
+    assert.deepEqual(result, deleteTrustlineBalanceChanges);
+  });
+});