Javascript Snippets

console-tricks.js

/************************************************************************
* CLIENT ONE-LINERS
*************************************************************************/

// Set top level domain cookie.
document.cookie = "token=12345; Max-Age=120; Secure; Domain=mozilla.org; Path=/;"

// Set a subdomain cookie.
document.cookie = "name=hello world; Max-Age=120; Secure; Domain=developer.mozilla.org; Path=/;"

// You can have cookies with the same name but with different paths and domains.
document.cookie = "name=1; Max-Age=60; Secure; Domain=mozilla.org;"
document.cookie = "name=2; Max-Age=60; Secure; Domain=mozilla.org; Path=/"
document.cookie = "name=3; Max-Age=60; Secure; Domain=developer.mozilla.org; Path=/;"

// Copies variable.
copy(temp1)
copy(JSON.stringify(temp1))

// Capture regex groups with variable
const string = 'ayyyy lmao'
const rgx    = /(?<firstVowel>[aeiou])/
string.match(rgx).groups.firstVowel

// Copies current selection to clipboard.
// https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand
// https://hackernoon.com/copying-text-to-clipboard-with-javascript-df4d4988697f
document.execCommand('copy')

// Copies text content of click to clipboard.
navigator.clipboard && navigator.clipboard.writeText(event.target.textContent);

// Makes page text editable.
document.designMode = 'on'

// Access third party frames on window.
window.frames

// Create bookmark and set this to URL to skip ads.
javascript:void(document.querySelector('video').currentTime = document.querySelector('video').duration)

// See all event listeners. Remember to remove listener when unmounting.
getEventListeners(document)

// See Slack Emoji authors.
Array.from(document.querySelectorAll('.author_cell > a')).map((a) => a.text.trim()).sort()

// Use this to click all links. 
Array.from(document.querySelectorAll('a.block')).forEach(a => a.click())

// Grab all the images from a page (namely instagram)
Array.from(document.images).forEach(img => console.log(img.getAttribute('src')))

// Like all facebook posts.
Array.from(document.body.querySelectorAll('.UFILikeLink')).forEach((a) => a.click())

// Selecting wildcard classes.
Array.from(document.querySelectorAll('div[class^="ManageSection__column-left"] .dp-checkbox')).forEach((a) => a.click())

/************************************************************************
* SERVER ONE-LINERS
*************************************************************************/

// Use Now to deploying static app serving a single page app.
ns ./build --cmd 'list ./content -s'

mongo.js

// Checks if nested property exists.
db.drafts.find({"collection_type": "web_advertising", "email": "jorge@email.com", "rows.222": { $exists: true } });

// Grabs the count.
db.drafts.find({"email": "jorge@email.com"}).count();

special-utils.js

/********************************************************************
* UTILS
*********************************************************************/
// https://stackoverflow.com/q/779379
setTimeout(function (callback) {
  // Offload Heavy computation. 
}, 0);

/********************************************************************
* JQUERY serializeArray
*********************************************************************/

// Converts form into Array of Objects.
// https://plainjs.com/javascript/ajax/serialize-form-data-into-an-array-46/
function serializeArray(form) {
  var field, l, s = [];
  if (typeof form == 'object' && form.nodeName == "FORM") {
    var len = form.elements.length;
    for (var i = 0; i < len; i++) {
      field = form.elements[i];
      if (field.name && !field.disabled && field.type != 'file' && field.type != 'reset' && field.type != 'submit' && field.type != 'button') {
        if (field.type == 'select-multiple') {
          l = form.elements[i].options.length;
          for (j = 0; j < l; j++) {
            if (field.options[j].selected)
              s[s.length] = {
                name: field.name,
                value: field.options[j].value
              };
          }
        } else if ((field.type != 'checkbox' && field.type != 'radio') || field.checked) {
          s[s.length] = {
            name: field.name,
            value: field.value
          };
        }
      }
    }
  }
  return s;
}


// Nodejs check if module is called directly
const CALLED_DIRECTLY = require.main === module;

function splitTextarea(text) {
  return text.trim().replace(/\s+/, '\n').replace(/\n{2,}/, '').split('\n');
}

// Download using fetch API..
import download from 'downloadjs';
const handleBufferDownload = (filename) => {
  res.arrayBuffer()
    .then((buffer) => {
      download(buffer, filename, contentType);
      stopLoading();
    });
};

// http://stackoverflow.com/a/23842171
encodeURIComparison = function() {
  var arr = [];
  for(var i=0; i<256; i++) {
    var char=String.fromCharCode(i);
    if(encodeURI(char) !== encodeURIComponent(char)) {
      arr.push({
        character: char,
        encodeURI: encodeURI(char),
        encodeURIComponent: encodeURIComponent(char)
      });
    }
  }
  console.table(arr);  
};

function encodeQueryParams (url, queryParams) {
  return Object.keys(queryParams).reduce((a, key) => {
    a.push(key + '=' + encodeURIComponent(queryParams[key]));
    return a;
  }, []).join('&');
}

let queryString = encodeQueryParams(queryParams);
url += url.indexOf('?') > -1 ? '&' : '?' + queryString;

/********************************************************************
* JQUERY COLOR CONTRAST 
*********************************************************************/
jQuery.Color.fn.contrastColor = function() {
    var r = this._rgba[0], g = this._rgba[1], b = this._rgba[2];
    return (((r*299)+(g*587)+(b*144))/1000) >= 131.5 ? "black" : "white";
};

// usage examples:
jQuery.Color("#bada55").contrastColor(); // "black"
element.css( "color", jQuery.Color( element, "backgroundColor" ).contrastColor() );

VSCode debugger with CRA tests

Sell bots
https://botbroker.io/bots

{
  // 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": [
    {
      "name": "Debug CRA Tests",
      "type": "node",
      "request": "launch",
      "runtimeExecutable": "${workspaceRoot}/node_modules/.bin/react-scripts",
      "args": ["test", "${relativeFile}", "--no-cache", "--modulePaths=src"],
      "env": { "CI": "true" },
      "cwd": "${workspaceRoot}",
      "protocol": "inspector",
      "console": "integratedTerminal",
      "internalConsoleOptions": "neverOpen"
  }
  ]
}

Mocking modules

jest.mock('stash/utils/experiments.js', function() {
  return {
    startExperiment: jest.fn(res => {
      return 0;
    }),
  };
});

import * as utils from 'stash/utils';
utils.isMobile = jest.fn().mockReturnValue(true);

Opening chrome with CORS disabled

open -n -a /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --args --user-data-dir="/tmp/chrome_dev_test" --disable-web-security

Mongo DB data migration

Binary

# Import database
mongorestore -h ds141168.mlab.com:41168 -d heroku_nl79h610 -u <user> -p <password> <input db directory>

# Export database
mongodump -h ds141168.mlab.com:41168 -d heroku_nl79h610 -u <user> -p <password> -o <output directory>

# Import collection
mongorestore -h ds141168.mlab.com:41168 -d heroku_nl79h610 -u <user> -p <password> <input .bson file>
# Export collection
mongodump -h ds141168.mlab.com:41168 -d heroku_nl79h610 -c <collection> -u <user> -p <password> -o <output directory>

JSON

# Import collection
mongoimport -h ds141168.mlab.com:41168 -d heroku_nl79h610 -c <collection> -u <user> -p <password> --file <input file>

# Export collection
mongoexport -h ds141168.mlab.com:41168 -d heroku_nl79h610 -c <collection> -u <user> -p <password> -o <output file>

CSV

# Import collection
mongoimport -h ds141168.mlab.com:41168 -d heroku_nl79h610 -c <collection> -u <user> -p <password> --file <input .csv file> --type csv --headerline

# Export collection
mongoexport -h ds141168.mlab.com:41168 -d heroku_nl79h610 -c <collection> -u <user> -p <password> -o <output .csv file> --csv -f <comma-separated list of field names>