Add ugly error handler

Author: beautifulcoder

ProperErrorHandlingJavaScript.njsproj

@@ -41,6 +41,9 @@
     <Compile Include="engines\render.js" />
     <Compile Include="routes\index.js" />
     <Compile Include="routes\route.js" />
+    <Compile Include="tests\engines\httpHandler.test.js">
+      <Publish>False</Publish>
+    </Compile>
     <Compile Include="tests\routes\index.request.js">
       <Publish>False</Publish>
     </Compile>
@@ -50,8 +53,12 @@
     <Compile Include="tests\scripts\error.test.js">
       <Publish>False</Publish>
     </Compile>
+    <Compile Include="tests\scripts\uglyHandler.test.js">
+      <Publish>False</Publish>
+    </Compile>
     <Content Include="scripts\badHandler.js" />
     <Content Include="scripts\error.js" />
+    <Content Include="scripts\uglyHandler.js" />
     <Content Include="package.json" />
     <Content Include="README.md" />
     <Content Include="views\index.html" />
@@ -62,6 +69,7 @@
     <Folder Include="scripts\" />
     <Folder Include="tests\" />
     <Folder Include="routes\" />
+    <Folder Include="tests\engines\" />
     <Folder Include="tests\scripts\" />
     <Folder Include="tests\routes\" />
     <Folder Include="views\" />

engines/httpHandler.js

@@ -1,7 +1,7 @@
-function httpHandler (err, res, content) {
+function httpHandler(err, res, content) {
     if (err) {
         res.writeHead(500, { 'Content-Type': 'text/plain' });
-        res.end('An error has occured: ' + err.message);
+        res.end('Error: ' + err.message);
     } else {
         res.writeHead(200, { 'Content-Type': content.type });
         res.end(content.response);

scripts/uglyHandler.js

@@ -0,0 +1,11 @@
+function uglyHandler(fn) {
+    try {
+        return fn();
+    } catch (e) {
+        throw Error('a new error');
+    }
+}
+
+if (typeof module === 'object') {
+    module.exports = uglyHandler;
+}

tests/engines/httpHandler.test.js

@@ -0,0 +1,39 @@
+var target = require('../../engines/httpHandler');
+var should = require('should');
+
+describe('An HTTP engine', function () {
+    it('handles errors', function () {
+        var res = responseMock();
+        target({ message: 'error' }, res);
+        res.getResult().should.equal('500text/plainError: error');
+    });
+
+    it('handles responses', function () {
+        var res = responseMock();
+        var content = { type: 'type', response: 'message' };
+        target(null, res, content);
+        res.getResult().should.equal('200typemessage');
+    });
+
+    function responseMock() {
+        var result = '';
+
+        return {
+            writeHead: writeHead,
+            end: end,
+            getResult: getResult
+        };
+
+        function writeHead(returnCode, header) {
+            result += returnCode + header['Content-Type'];
+        }
+
+        function end(body) {
+            result += body;
+        }
+
+        function getResult() {
+            return result;
+        }
+    }
+});

tests/scripts/badHandler.test.js

@@ -1,7 +1,7 @@
 var target = require('../../scripts/badHandler');
 var should = require('should');
 
-describe('A bad handler', function() {
+describe('A bad error handler', function() {
     it('returns a value without errors', function() {
         var fn = function() {
             return 1;

tests/scripts/uglyHandler.test.js

@@ -0,0 +1,21 @@
+var target = require('../../scripts/uglyHandler');
+var should = require('should');
+
+describe('An ugly error handler', function () {
+    it('returns a value without errors', function () {
+        var fn = function () {
+            return 1;
+        };
+        var result = target(fn);
+        result.should.equal(1);
+    });
+
+    it('returns a new error with errors', function () {
+        var fn = function () {
+            throw new TypeError('type error');
+        };
+        should.throws(function () {
+            target(fn);
+        }, Error);
+    });
+});