From 4730ac916782c03cde9cdc529a19569e0000ebc8 Mon Sep 17 00:00:00 2001
From: tintinthong <justinthong93@gmail.com>
Date: Fri, 3 Apr 2020 22:07:05 +0800
Subject: [PATCH 1/2] Add numberOfLevel function

---
 lib/dep_graph.js | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/lib/dep_graph.js b/lib/dep_graph.js
index 1954a62..15aa8de 100644
--- a/lib/dep_graph.js
+++ b/lib/dep_graph.js
@@ -177,6 +177,34 @@ DepGraph.prototype = {
         this.incomingEdges[to].splice(idx, 1);
       }
     }
+  },
+    /**
+    * Get the height of a tree 
+    * https://en.wikipedia.org/wiki/Tree_(graph_theory) 
+   */
+  numberOfLevel: function() {
+    var source = this
+    var outgoingEdges = this.outgoingEdges
+    if(this.circular){
+      console.log("numberOfLevel only works on trees")
+      return
+    }
+    var keys = Object.keys(source.nodes)
+    var out = 0
+    keys.forEach(function(n){
+      var result = [];
+      var DFS = createDFS(
+        outgoingEdges,
+        false,
+        result,
+        false
+      );
+      DFS(n);
+      if(result.length > out) {
+        out = result.length
+      }
+    })
+    return out
   },
   /**
    * Return a clone of the dependency graph. If any custom data is attached

From a65af80ef84be5ea905f0f697e10029c320f1133 Mon Sep 17 00:00:00 2001
From: tintinthong <justinthong93@gmail.com>
Date: Sat, 4 Apr 2020 03:23:30 +0800
Subject: [PATCH 2/2] Add getNodesEachLevel

---
 lib/dep_graph.js | 55 +++++++++++++++++++++++++++---------------------
 1 file changed, 31 insertions(+), 24 deletions(-)

diff --git a/lib/dep_graph.js b/lib/dep_graph.js
index 15aa8de..8ffe7ef 100644
--- a/lib/dep_graph.js
+++ b/lib/dep_graph.js
@@ -178,33 +178,40 @@ DepGraph.prototype = {
       }
     }
   },
-    /**
-    * Get the height of a tree 
-    * https://en.wikipedia.org/wiki/Tree_(graph_theory) 
+  /**
+   * Combines all outgoingEdges of list of nodes 
    */
-  numberOfLevel: function() {
-    var source = this
-    var outgoingEdges = this.outgoingEdges
+  getNodesNextLevel: function(nodes) {
+    var source = this;
+    var nodesInLevel = []
+    for (i = 0; i < nodes.length; i++) {
+      nodesInLevel = nodesInLevel.concat(source.outgoingEdges[nodes[i]])
+    }
+    return [...new Set(nodesInLevel)]
+  },
+  /**
+   * Get nodes at each level 
+   * .e.g getNodesEachLevel() 
+   */
+  getNodesEachLevel: function(nodes, out, level) {
     if(this.circular){
-      console.log("numberOfLevel only works on trees")
-      return
+      throw new Error("getNodesEachLevel only works for trees")
     }
-    var keys = Object.keys(source.nodes)
-    var out = 0
-    keys.forEach(function(n){
-      var result = [];
-      var DFS = createDFS(
-        outgoingEdges,
-        false,
-        result,
-        false
-      );
-      DFS(n);
-      if(result.length > out) {
-        out = result.length
-      }
-    })
-    return out
+    if(out == undefined){
+      out = []
+    }
+    if(nodes == undefined){
+      nodes = [Object.keys(this.nodes)[0]] //set root
+      out.push(nodes)
+      level = 0
+    }
+    if(this.getNodesNextLevel(nodes).length == 0){
+      return out
+    }else{
+      out.push(this.getNodesNextLevel(nodes))
+    }
+    level++
+    return this.getNodesEachLevel(out[level], out, level)
   },
   /**
    * Return a clone of the dependency graph. If any custom data is attached