14-debug.md

id	title
14-debug	Debugging & Troubleshooting

• Copy and paste the error into Google.

Build Errors

• Ensure that you have the correct dependencies in your package.json and run a npm install

Exercises

• Exercise 1
• Exercise 2

Debugging

Express Application

• Use VS Code's Debug tools
• Select the node file you want to run. ie. index.js
• Add a configuration for the application, by clicking the dropdown next to the play Debug and select Add Configuration and select Node
• It should autofill with the details of the project and look like the following:

  {
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
      {
        "type": "node",
        "request": "launch",
        "name": "Express App",
        "skipFiles": ["<node_internals>/**"],
        "program": "${workspaceFolder}/index.js"
      }
    ]
  }

• Hit the play debug button to run the application
• Place breakpoint in the application to stop the application to view the line.

Exercises

• Exercise 3

Using Breakpoints In Chrome DevTools

• Click the Sources tab.
• Open the file containing the line of code you want to break on.
• Go the line of code.
• To the left of the line of code is the line number column. Click on it. A blue icon appears on top of the line number column.

Exercises

• Exercise 4
• Exercise 5

Resources

• Node.js debugging in VS Code
• How To Pause Your Code With Breakpoints In Chrome DevTools