initial commit

README.md

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+# Debugging Tips
+
+A large part of a software developers job is to find problems. To find problems in existing applications and to minimize problems in applications.
+
+In this session we will look at tips, tricks and techniques for tracking down problems in our applications.
+
+## We will look at:
+* How to track down errors
+* Analyzing stack traces
+* Isolating an issue
+* Debugging tools
+
+## How to track down errors:
+* Understanding the big picture
+* What areas in the application are error prone
+* What clues do we have?
+* How to read error messages
+
+## Analyzing stack traces:
+* Which code is yours?
+* At which line is the error?
+* Why could things go wrong at that line?
+* Silent failure?
+
+## Isolating an issue:
+* Remove code - check if it still fails
+* Put code back until the error happens again
+* Look at lines before & after the problem
+
+## Debugging tools
+* Chrome developer tools - break points
+* print things to the console.
+* break problem down into components
+* use log files - with various log levels
+
+#Setup
+
+## Create a database
+
+```sql
+CREATE DATABASE debugging_tips;
+CREATE USER debugger@localhost IDENTIFIED BY 'password';
+GRANT ALL PRIVILEGES ON debugging_tips.* TO debugger@localhost;
+FLUSH PRIVILEGES;
+```
+
+## Create tables
+
+```sql
+create table issues (
+  id int not null auto_increment,
+  heading char(100) not null,
+  description text,
+  primary key(id)
+);
+```
+
+## Install the dependencies
+
+Using: `npm install`
+
+## Tools for break points
+
+  [Node Inspector](https://github.com/node-inspector/node-inspector)
+
+  [Using MS Visual Code](http://stackoverflow.com/questions/30023736/mocha-breakpoints-using-visual-studio-code)

errors.txt

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+Errors
+======
+* remove a callback from the module
+* using an undefined route
+* using an undefined method on a route that exists
+* invalid database credentials
+* can not get post
+* redirect invalid
+* unexpected token - no comma where there should be one
+* edit the text area for the edit
+* uninstall module

index.js

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+'use strict';
+
+var express = require('express'),
+    exphbs  = require('express-handlebars'),
+    mysql = require('mysql'),
+    myConnection = require('express-myconnection'),
+    bodyParser = require('body-parser'),
+    issues = require('./issues');
+
+var app = express();
+
+var dbOptions = {
+      host: 'localhost',
+      user: 'debugger',
+      password: 'passworddd',
+      port: 3306,
+      database: 'debugging_tips'
+};
+
+//setup template handlebars as the template engine
+app.engine('handlebars', exphbs({defaultLayout: 'main'}));
+app.set('view engine', 'handlebars');
+
+app.use(express.static(__dirname + '/public'));
+
+//setup middleware
+app.use(myConnection(mysql, dbOptions, 'single'));
+// parse application/x-www-form-urlencoded
+app.use(bodyParser.urlencoded({ extended: false }))
+// parse application/json
+app.use(bodyParser.json())
+
+function errorHandler(err, req, res, next) {
+  res.status(500);
+  res.render('error', { error: err });
+}
+
+//setup the handlers
+app.get('/', issues.all);
+app.get('/issues', issues.all);
+app.get('/issues/add' issues.showAdd);
+app.get('/issues/:id', issues.get);
+app.post('/issues/update/:id', issues.update);
+app.post('/issuesss', issues.add);
+app.get('/issues/delete/:id', issues.delete);
+
+//this should be a post but this is only an illustration of CRUD - not on good practices
+app.delete('/issues/:id', issues.delete);
+
+app.use(errorHandler);
+
+//configure the port number using and environment number
+var portNumber = process.env.CRUD_PORT_NR || 3000;
+
+//start everything up
+app.listen(portNumber, function () {
+    console.log('Debugging Tips app running at port # :', portNumber);
+});

issues.js

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+var logger = require('./log');
+
+exports.all = function (req, res) {
+    req.getConnection(function(err, connection){
+        connection.query("select * from issues", function(err, results){
+            res.render('issues', {issues : results})
+        });
+    });
+}
+
+exports.get = function (req, res) {
+    req.getConnection(function(err, connection){
+        connection.query("select * from issues where id = ?", req.params.id, function(err, results){
+            console.log(results);
+            return res.render('issue_edit', {issue : results[0]})
+        });
+    });
+
+}
+
+exports.update = function (req, res) {
+    req.getConnection(function(err, connection){
+        var data = {
+            heading : req.body.heading,
+            description : req.body.description
+        };
+
+        connection.query("update issues set ? where id = ?", [data, req.params.id], function(err, results){
+            // what will happen here?
+            return res.redirect("/issues");
+        });
+    });
+}
+
+exports.showAdd = function (req, res) {
+    res.render('isue')
+}
+
+exports.add = function (req, res) {
+
+    var data = {
+        heading : req.body.heading,
+        description : req.body.description
+    }
+    req.getConnection(function(err, connection){
+        // what can I do better here?
+        connection.query("insert into issues set ?", data, function(err, results){
+            // what can I do better here?
+            res.redirect('/issues')
+        });
+    });
+}
+
+exports.delete = function (req, res, next) {
+    req.getConnection(function(err, connection){
+        connection.query("delete from isues where id = ?", req.params.id, function(err, results){
+            //if (err) return next(err);
+            res.redirect('/issues')
+        });
+    });
+
+}

log.js

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+var winston = require('winston');
+
+winston.add(winston.transports.File, { filename: "./logs/logger.log" });
+winston.info('Chill Winston, the logs are being captured...');
+
+module.exports=winston;

package.json

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+{
+  "name": "debugging-tips",
+  "version": "1.0.0",
+  "description": "A large part of a software developers job is to find problems. To find problems in existing applications and to minimize problems in applications.",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/codex-academy/DebuggingTips.git"
+  },
+  "author": "",
+  "license": "ISC",
+  "bugs": {
+    "url": "https://github.com/codex-academy/DebuggingTips/issues"
+  },
+  "homepage": "https://github.com/codex-academy/DebuggingTips#readme",
+  "dependencies": {
+    "body-parser": "^1.9.2",
+    "express": "^4.10.2",
+    "express-handlebars": "^1.1.0",
+    "express-myconnection": "^1.0.4",
+    "mysql": "^2.5.3",
+    "winston": "^2.0.1"
+  }
+}