TILs - Fueling Curiosity, One Insight at a Time

At Codemancers, we believe every day is an opportunity to grow. This section is where our team shares bite-sized discoveries, technical breakthroughs and fascinating nuggets of wisdom we've stumbled upon in our work.

Published: Jun 25, 2024
Author: Adithya Hebbar
System Analyst

In JavaScript, console.time is a method that helps you measure the time it takes for a specific block of code to execute. It's like a stopwatch for your code.

Code

// Start the timer 
console.time('myTimer');
for (let i = 0; i < 1000000; i++) { 
 // Some code here 
}
// Stop the timer 
console.timeEnd('myTimer');

So, when you run this code, you'll see something like: "myTimer: 1.358ms"

#javascript

Published: Jun 25, 2024
Author: Ashwani Kumar Jha
Senior System Analyst

Performance API

Seems super useful for tracking web performance, it let us measure various performance metrics of web pages, like how long specific operations take.

1. performance.now()
◦ Provides the current time in milliseconds with high precision, can be useful for measuring how long specific tasks take.
2. PerformanceEntry
◦ Object representing a metric. It includes:
▪︎ navigation: Information about page loads.
▪︎ resource: Data on loaded resources like scripts and images.
▪︎ mark: User-defined timestamps.
▪︎ measure: Duration between two marks.
3. PerformanceNavigationTiming
◦ Specific type of PerformanceEntry for page navigation metrics.
◦ Tells us if a page load is due to a navigation, reload, or history action.
◦ eg properties: domComplete, domContentLoadedEventEnd, type.
Probable use Cases:
• Can help us analyze how long different parts of the page load take.
• Can help us check how long it takes to load each resource.
• Can help us determine if a page is reloaded or newly navigated.
#performance #browser

Published: Jun 20, 2024
Author: Ashwani Kumar Jha
Senior System Analyst

EJS, the templating engine for JavaScript, allows us to generate HTML markup with plain JavaScript.

By default, EJS escapes any HTML entities in the output to prevent issues such as cross-site scripting. This is done by replacing characters like <, >, &, and " with their respective HTML entity codes.

For example:

Code

- `&` is replaced with `&`
- `<` is replaced with `<`
- `>` is replaced with `>`
- `"` or `'` (double or single quote) is replaced with `&quot;` or `&#39;` respectively.

Unescape HTML entities with <%- %>

If we want EJS to output our data without escaping HTML entities, replace <%= %> with <%- %>. This instructs EJS to render the data as unescaped.

Published: Jun 20, 2024
Author: Giritharan
System Analyst

My Rails application is named xyz. When I tried to create a scaffold with the same name as the application, it caused a below error.

Code

The name 'Xyz' is either already used in your application or reserved by Ruby on Rails. Please choose an alternative or use --skip-collision-check or --force to skip this check and run this generator again.

To fix this, I changed the module name in application.rb to abc. After making this change, everything worked. It's always best to avoid using the same name for both the model and the application.

#rails-naming-convention #rails

Published: Jun 19, 2024
Author: Giritharan
System Analyst

After pushing my changes to the Fly, I noticed that my Application JS controller wasn't being found. The problem was due to an incorrect line in app/javascript/controllers/application.js. It originally had:

Code

import { application } from "./application";

To fix it, I changed it to:

Code

import { application } from "controllers/application";

These changes ensured that the request was directed to the correct location, and the Stimulus JS controller started working.

#stimulus #assert-not-loading #rails

Published: Jun 19, 2024
Author: Ayush Srivastava
System Analyst

Common procedure to monitor data in Devops Environment

First we need a source of metrics that can be Applications, Databases, Containers etc

After that we need Exporters

Exporters are components that collect and export metrics from various systems, applications, and services, making them available to monitoring tools

Then we need Datasource

Datasource aggregates, stores, and allows querying of the metrics collected from Exporters, making it the data source for visualization tools and alerting mechanisms.

Collected data is stored in Time Series database

A time series database (TSDB) is a special type of database designed to store and manage data that is recorded over time. Each piece of data has a timestamp, which helps keep track of when it was collected.

Then comes the visualisation part

We can use tools like Grafana that make use of the data that is stored in Time Series Database like prometheus to visualise data

#monitoring #devops

Published: Jun 18, 2024
Author: Adithya Hebbar
System Analyst

util.inspect use-case:

• Without util.inspect

Code

const obj = {
  name: "Adi",
  age: 24,
  details: { details1: { details2: { hobbies: "travelling" } } },
};
console.log(obj);
//Output: { name: 'Alice', age: 30, details: { details1: { details2: [Object] } } }

• With util.inspect

Code

import util from "util";

const obj = {
  name: "Adi",
  age: 24,
  details: { details1: { details2: { hobbies: "travelling" } } },
};

console.log(util.inspect(obj, { depth: null, colors: true }));

//Output: { name: 'Adi', age: 24, details: { details1: { details2: { hobbies: 'travelling' } } } }

console.log doesn't show all details of complex objects, especially nested ones or hidden properties. util.inspect gives a complete and customizable view for better debugging and understanding.

#javascript

Published: Jun 18, 2024
Author: Adithya Hebbar
System Analyst

To kill a process running on a specific port in mac:
1. lsof -i :<port_number>
2. Note the PID of the process from the output.
3. kill -9 <pid>
#killprocess

Published: Jun 17, 2024
Author: Ayush Srivastava
System Analyst

Password recovery command for Influxdb when running in local as the UI does not provide any other way to set a new password if you have forgotten

Code

influxd recovery user update \
  --username example-username \
  --password ExAmPL3-paS5W0rD

#influxdb

Published: Jun 17, 2024
Author: Ayush Srivastava
System Analyst

Uninstall / remove a Homebrew package including all its dependencies

Code

brew tap ggpeti/rmrec
brew rmrec pkgname

#homebrew

Showing 21 to 23 of 82 results

Ready to Build Something Amazing?

Codemancers can bring your vision to life and help you achieve your goals

Let's Talk

Address
2nd Floor, Zee Plaza,
No. 1678, 27th Main Rd,
Sector 2, HSR Layout,
Bengaluru, Karnataka 560102
Contact
hello@codemancers.com
+91-9731601276