From d5591189eb04b91a7642f72034b2751a071baae5 Mon Sep 17 00:00:00 2001
From: michielmulders <michielmulders1@gmail.com>
Date: Thu, 2 Nov 2017 19:46:47 +0100
Subject: [PATCH 1/3] Added Utility method for topological sort

---
 package.json                             |  1 +
 src/transaction/utils/topologySorting.js | 26 ++++++++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 src/transaction/utils/topologySorting.js

diff --git a/package.json b/package.json
index 20dfb87a..4bd1a804 100644
--- a/package.json
+++ b/package.json
@@ -75,6 +75,7 @@
     "json-stable-stringify": "^1.0.1",
     "query-string": "^5.0.0",
     "sprintf-js": "^1.0.3",
+    "toposort": "^1.0.6",
     "tweetnacl": "^1.0.0"
   },
   "keywords": [
diff --git a/src/transaction/utils/topologySorting.js b/src/transaction/utils/topologySorting.js
new file mode 100644
index 00000000..b65b37aa
--- /dev/null
+++ b/src/transaction/utils/topologySorting.js
@@ -0,0 +1,26 @@
+import toposort from 'toposort'
+
+function generateGraph(txs) {
+    const graph = []
+    for (var tx of txs) {
+        for (var input of tx.inputs) {
+            if (!!input.fulfills) {
+                graph.push([tx.id, input.fulfills.transaction_id])
+            }
+        }
+    }
+    return graph
+}
+
+
+/**
+ * @public
+ * Topological sort algorithm for transactions
+ * Used for endpoint: /transactions?assetId
+ * @param {object} txs Array of transactions
+ * @returns {object} Returns transactions in order of dependency
+ */
+export default function topsortTransactions(txs) {
+    const graph = generateGraph(txs)
+    return toposort(graph).reverse()
+}

From 7878c02e970c17d590d578d63aeb9562f40a9c88 Mon Sep 17 00:00:00 2001
From: michielmulders <michielmulders1@gmail.com>
Date: Thu, 2 Nov 2017 19:57:29 +0100
Subject: [PATCH 2/3] small fix

---
 src/transaction/utils/topologySorting.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/transaction/utils/topologySorting.js b/src/transaction/utils/topologySorting.js
index b65b37aa..c8f45153 100644
--- a/src/transaction/utils/topologySorting.js
+++ b/src/transaction/utils/topologySorting.js
@@ -2,8 +2,8 @@ import toposort from 'toposort'
 
 function generateGraph(txs) {
     const graph = []
-    for (var tx of txs) {
-        for (var input of tx.inputs) {
+    for (const tx of txs) {
+        for (const input of tx.inputs) {
             if (!!input.fulfills) {
                 graph.push([tx.id, input.fulfills.transaction_id])
             }

From c6cb3e82834e32a84526b7e11dd627d1ece1f44c Mon Sep 17 00:00:00 2001
From: michielmulders <michielmulders1@gmail.com>
Date: Thu, 2 Nov 2017 20:09:33 +0100
Subject: [PATCH 3/3] ESLint fixes

---
 src/transaction/utils/topologySorting.js | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/transaction/utils/topologySorting.js b/src/transaction/utils/topologySorting.js
index c8f45153..54085e97 100644
--- a/src/transaction/utils/topologySorting.js
+++ b/src/transaction/utils/topologySorting.js
@@ -2,13 +2,14 @@ import toposort from 'toposort'
 
 function generateGraph(txs) {
     const graph = []
-    for (const tx of txs) {
-        for (const input of tx.inputs) {
-            if (!!input.fulfills) {
+    txs.forEach(tx => {
+        tx.inputs.forEach(input => {
+            if (input.fulfills) {
                 graph.push([tx.id, input.fulfills.transaction_id])
             }
-        }
-    }
+        })
+    })
+
     return graph
 }