diff --git a/src/chapter4/ch4-q01.spec.js b/src/chapter4/ch4-q01.spec.js
index 1371004..57e05dc 100644
--- a/src/chapter4/ch4-q01.spec.js
+++ b/src/chapter4/ch4-q01.spec.js
@@ -1,12 +1,44 @@
-//import { expect } from 'chai';
-//import * as helpers from './helpers';
+import { expect } from 'chai';
 import * as funcs from './ch4-q01';
 
 for (let key in funcs) {
-//  let func = funcs[key];
+  let func = funcs[key];
 
   describe('ch4-q01: ' + key, function() {
-    // TODO
+    const graph = {
+      'a': ['a', 'c', 'd'],
+      'b': ['e'],
+      'c': ['c', 'd', 'f'],
+      'd': ['f', 'd'],
+      'e': ['b', 'g'],
+      'f': ['e'],
+      'g': ['i'],
+      'h': ['b', 'c'],
+      'i': ['i', 'e']
+    };
+    const testCases = [
+      { init: 'a', finish: 'b' },
+      { init: 'a', finish: 'f' },
+      { init: 'a', finish: 'a' },
+      { init: 'h', finish: 'i' },
+      { init: 'i', finish: 'i' }
+    ];
+    it('returns true if nodes are connected', function() {
+      testCases.forEach((test) => {
+        expect(func(graph, test.init, test.finish)).to.be.true;
+      });
+    });
+    const testCases2 = [
+      { init: 'i', finish: 'h' },
+      { init: 'c', finish: 'a' },
+      { init: 'a', finish: 'h' },
+      { init: 'f', finish: 'd' },
+      { init: 'g', finish: 'f' }
+    ];
+    it('returns false if nodes are not connected', function() {
+      testCases2.forEach((test) => {
+        expect(func(graph, test.init, test.finish)).to.be.false;
+      });
+    });
   });
-
 }