Adding tests for the TextHelper

Author: andrerpena

package.json

@@ -4,6 +4,7 @@
   "description": "A react markdown-editor like Stackoverflow and Github",
   "main": "index.js",
   "scripts": {
+    "test": "mocha --timeout 15000 --compilers js:babel-register ./test/*Spec.js",
     "start": "cross-env NODE_ENV=development babel-node ./demo/server.js",
     "build": "cross-env NODE_ENV=production gulp build"
   },
@@ -30,6 +31,7 @@
     "babel-preset-react-hmre": "^1.1.1",
     "babel-preset-stage-0": "^6.16.0",
     "bootstrap": "^4.0.0-alpha.5",
+    "chai": "^3.5.0",
     "colors": "^1.1.2",
     "cross-env": "^3.1.3",
     "css-loader": "^0.26.0",
@@ -41,6 +43,7 @@
     "gulp-cli": "^1.2.2",
     "less": "^2.7.1",
     "less-loader": "^2.2.3",
+    "mocha": "^3.2.0",
     "node-sass": "^3.13.0",
     "react-hot-loader": "^3.0.0-beta.6",
     "react-redux": "^4.4.6",

test/TextHelperSpec.js

@@ -0,0 +1,24 @@
+import { assert } from 'chai';
+import { insertText } from '../src/TextHelper';
+
+describe("TextHelperSpec.js", function () {
+    describe('insertText', function () {
+        it('should work mid-string', function () {
+            var text = insertText('bob school', 'went to ', 4);
+            assert.strictEqual(text, 'bob went to school');
+        });
+        it('should work in the start', function () {
+            var text = insertText('went to school', 'bob ', 0);
+            assert.strictEqual(text, 'bob went to school');
+        });
+        it('should work in the end', function () {
+            var text = insertText('bob went to', ' school', 11);
+            assert.strictEqual(text, 'bob went to school');
+        });
+
+        it('should work with a position greater than the max', function () {
+            var text = insertText('bob went to', ' school', 20);
+            assert.strictEqual(text, 'bob went to school');
+        });
+    })
+});