How to display and debug NodeJS errors using Llama Logs?

This article introduces you to the Node development artifact-Llama Logs. Use Llama Logs to visualize Node errors in real time. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

Related recommendations: "nodejs Tutorial"

Do you want to know what happens inside the program? Want to visually inspect its inner workings?

The above animation shows an example of Llama Logs. It's a new tool I created that lets you see the inner workings of your application in real time. It's ready and you can start using it in your applications for free.

Below, I will demonstrate through an example how to use Llama Logs to display and debug errors that occur in a basic Express application.

Start

I will write a basic quick app that receives the user's email via a url parameter and if the email is llamalogs .com domain, save it to the database.

The basic logic will be as follows

app.get('/', (req, res) => {
  let customerEmail = req.query.email
  let isDomainOk = domainCheck(customerEmail)

  if (isDomainOk) {
      saveEmail(customerEmail)
  }

  res.send('We received your email')
})

Now the problem is that I have to write some code that checks if the user forgets to include the @domain part in the email. Something will go wrong.

const domainCheck = (customerEmail) => {
  // toLowerCase will fail if the [1] value is undefined!
  const domain = customerEmail.split("@")[1].toLowerCase()
  const domainIsOk = domain === "llamalogs.com"
  return domainIsOk
}

Visualization with Llama Logs

Llama Logs is very easy to set up. Once you've signed up for llamalogs.com, all you need to do is install the client via npm and start logging, and Llama Logs will automatically convert your logs into interactive graphs.

So, for example, let's update the domainCheck method to the following

const domainCheck = (customerEmail) => {
  try {
    const domain = customerEmail.split("@")[1].toLowerCase()
    const domainIsOk = domain === "llamalogs.com"

    LlamaLogs.log({ sender: 'Server', receiver: 'Domain Check' })

    return domainIsOk

  } catch (e) {
    LlamaLogs.log({ 
      sender: 'Server', 
      receiver: 'Domain Check', 
      message: `input: ${customerEmail}; Error: ${e}`,
      isError: true
    })
  }
}

We add a log case for both successful and failed results. Llama Logs will then automatically visualize the activity in the application as a series of events between components using the names provided in the sender, receiver and isError properties. Moving points.

In the graphic below we can see the results of running several calls to the server with valid emails and the call that caused the error.

Debugging

Better than visualizing activity in charts, Llama Logs lets you get data from errors in real time.

Remember in the domainCheck method we attached this property to Llama Log?

message: `input: ${customerEmail}; Error: ${e}`,

By using this message attribute, it means that when we hover the mouse over the red error point, it will display the message. The image below shows the error I'm stuck on, it says the request has the email parameter == "jd", and the email domain is missing.

By visualizing errors in your system with Llama Logs, you can discover the source of errors faster and easier than ever!

More information

Interested friends please visit https://llamalogs.com/ for more information. The app is free and available today. If you have any questions, please feel free to contact me at andrew@llamalogs.com.

Full Code

I think this is a small Express application and the easiest way is to include all the code in this blog post.

const express = require('express')
const { LlamaLogs } = require('llamalogs');

LlamaLogs.init({
  accountKey: 'YOUR_ACCOUNT_KEY',
  graphName: 'YOUR_GRAPH_NAME'
});

const app = express()
const port = 3000

app.get('/', (req, res) => {
  LlamaLogs.log({ sender: 'User', receiver: 'Server' })

  let customerEmail = req.query.email
  let isDomainOk = domainCheck(customerEmail)

  if (isDomainOk) {
      saveEmail(customerEmail)
  }

  res.send('We received your email')
})

app.listen(port, () => {
  console.log(`Example app listening at http://localhost:${port}`)
})


const domainCheck = (customerEmail) => {
  try {
    const domain = customerEmail.split("@")[1].toLowerCase()
    const domainIsOk = domain === "llamalogs.com"

    LlamaLogs.log({ sender: 'Server', receiver: 'Domain Check' })

    return domainIsOk

  } catch (e) {
    LlamaLogs.log({ 
      sender: 'Server', 
      receiver: 'Domain Check', 
      message: `input: ${customerEmail}; Error: ${e}`,
      isError: true
    })
  }
}

const saveEmail = (customerEmail) => {
  // pretend we are saving to a database here
  LlamaLogs.log({ sender: 'Domain Check', receiver: 'Database' })
}

Original text: https://dev.to/bakenator/visualize-nodejs-errors-in-real-time-with-llama-logs-3c18

Author: bakenator

Translation address: https://segmentfault.com/a/1190000025186252

For more programming-related knowledge, please visit: Programming Video! !

The above is the detailed content of How to display and debug NodeJS errors using Llama Logs?. For more information, please follow other related articles on the PHP Chinese website!