Snippets

Like most programmers, I keep going to some projects to copy some bits of code. From now on, I'm going to list them in one place.

Bash

Gource

Make a video of the evolution of a git repo

gource \
  --hide dirnames,filenames \
  --seconds-per-day 0.1 \
  --auto-skip-seconds 1 -1280x720 -o - |
  ffmpeg \
    -y -r 60 -f image2pipe\
    -vcodec ppm -i -\
    -vcodec libx264 \
    -preset ultrafast \
    -pix_fmt yuv420p \
    -crf 1 \
    -threads 0 \
    -bf 0 \
    gource.mp4

Python

Custom Errors

To create custom errors

class AgeNotInRangeError(Exception):
    """
      Exception raised for errors in the input age.

        - age     - age which caused the error
        - message - explanation of the error
    """

    def __init__(self, age, message="Age is not in range"):
        self.age = age
        self.message = message
        super().__init__(self.message)

    def __str__(self):
        return f'{self.age} -> {self.message}'


age = int(input("Enter age amount: "))
if age <= 18:
    raise AgeNotInRangeError(age)

Tests

To do some test-driven development, create a file at tests/test_{name}.py with some tests:

import unittest

class TestEvents(unittest.TestCase):
    def test_{name}(self):
        self.assertEqual(1, 1)

To run the tests, use python -m unittest discover -s tests/

Django

Create a model with a created_at and udpated_at:

class MyModel(models.Model):
    # ...
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

Typescript and/or javascript

Custom Errors

To create custom errors

class HttpStatusError extends Error {
  private data: Errors
  private status: number

  constructor(status: number, data: Errors) {
    const message = `Got status ${status} for request`
    super(message)
    this.name = 'HttpStatusError'
    this.data = data
    this.status = status
  }
}

To use and throw them

throw new HttpStatusError(500, { error: 'Try again later' })

Later, to catch and use them

if (err instanceof HttpStatusError) {
  // ...
}

if (err.name == 'HttpStatusError') {
  // ...
}

React

Dump some variable so we can visually inspect it:

<pre>{JSON.stringify(variable, null, 4)}</pre>

Tailwind

Rows and columns

<div class="container mx-auto max-w-6xl mt-8">
  <div class="flex border border-blue-600 -mx-4">
    <div class="w-1/4 border border-red-600 mx-4">1</div>
    <div class="w-1/4 border border-red-600 mx-4">2</div>
    <div class="w-1/4 border border-red-600 mx-4">3</div>
    <div class="w-1/4 border border-red-600 mx-4">4</div>
  </div>
</div>