Add a path creation function

kkowar · Sep 24, 2014 · 14c5bce · 14c5bce
1 parent 722e6dd
commit 14c5bce
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Showing 3 changed files with 29 additions and 1 deletion.
diff --git a/lib/graph.js b/lib/graph.js
@@ -119,6 +119,16 @@ Graph.prototype.allEdges = function() {
   return _.keys(this._edges);
 };
 
+Graph.prototype.path = function() {
+  var self = this,
+      segments = new Array(arguments.length - 1);
+  _.reduce(arguments, function(v, w, i) {
+    segments[i - 1] = self.edge(v, w);
+    return w;
+  });
+  return segments;
+};
+
 Graph.prototype.edge = function(v, w, name) {
   var e = arguments.length === 1 ? v : this.edgeKey(v, w, name),
       edge;

diff --git a/src/bench.js b/src/bench.js
@@ -104,6 +104,10 @@ NODE_SIZES.forEach(function(size) {
     g.allEdges();
   });
 
+  runBenchmark("path" + nameSuffix, function() {
+    g.path("a", "b", "c", "d", "e");
+  });
+
   runBenchmark("edge" + nameSuffix, function() {
     g.edge("from", "to");
   });

diff --git a/test/graph-test.js b/test/graph-test.js
@@ -104,7 +104,6 @@ describe("Graph", function() {
     });
   });
 
-
   describe("successors", function() {
     it("returns undefined for a node that is not in the graph", function() {
       expect(g.successors("a")).to.be.undefined;
@@ -148,6 +147,21 @@ describe("Graph", function() {
     });
   });
 
+  describe("path", function() {
+    it("creates a path of mutiple edges", function() {
+      g.path("a", "b", "c");
+      expect(g.hasEdge("a", "b")).to.be.true;
+      expect(g.hasEdge("b", "c")).to.be.true;
+    });
+
+    it("returns the segments of the path", function() {
+      var segments = g.path("a", "b", "c");
+      expect(segments).to.have.length(2);
+      expect(segments[0]).to.equal(g.edge("a", "b"));
+      expect(segments[1]).to.equal(g.edge("b", "c"));
+    });
+  });
+
   describe("edge", function() {
     it("creates the edge if it isn't part of the graph", function() {
       g.node("a");