...match a certain criteria or not, Enumerable#partition can come in handy. # Enumerable#partition returns two arrays, # the first containing the elements of enum # for which the block evaluates to...

JavaScript Create an object with no properties with Object.create(null) => {} The comma operator returns its last expression

...simply mock time using Timecop.travel or its respective Spreewald steps and the browser will return the same time in new Date(). If you would like to stop the time from...

...document.body.append(overlay);function getElement(event){overlay.style.pointerEvents='none';var element=document.elementFromPoint(event.clientX,event.clientY);overlay.style.pointerEvents='auto';return element};document.addEventListener('mousemove',function(event){var element=getElement(event);if(!element)return;var position=element.getBoundingClientRect...

...document.body.append(overlay); function getElement(event) { overlay.style.pointerEvents = 'none'; var element = document.elementFromPoint(event.clientX, event.clientY); overlay.style.pointerEvents = 'auto'; return element; } document.addEventListener('mousemove', function(event) { var element = getElement(event); if (!element) return; var position = element.getBoundingClientRect...

...developer who just wrote it. To check its readability, a good strategy is to return after a few months. You will have forgotten the direct context, but will still be...

...achieve this by using a callback. before_initialize :set_newsletter private def set_newsletter return unless [nil, ''].include?(receive_newsletter) self.receive_newsletter = (user.role == 'customer') end Note: When using active_type...

...Our assumption is that the element is considered visible (i.e. Capybara::Selenium::ChromeNode#visible? returns true for such elements) but the Selenium driver wants to actually click the center of...

...and .then() do not behave the same. In particular, if a standard promise callback returns another promise, this will delay the resolution of all later promises. jQuery's then behaves...

...the response, make a second request to /bar: var promise = $.ajax('/foo').done(function() { return $.ajax('/bar'); }); Quiz: When does promise resolve? Well, if you use done, it will resolve...

...a?(String) && value.blank? - nil - else - value - end activerecord/lib/active_record/connection_adapters/column.rb + def type_cast_for_write(value) + return value unless number? + + if value == false + 0 + elsif value == true + 1 + elsif value.is_a?(String...

...call Nokogiri::HTML to be more liberal about accepting invalid XML. xml / 'list item' returns all matching nodes; list item is used like a CSS selector xml / './/list/item' also returns...

...an XPath selector XPath seems to be triggered by a leading . or / xml % 'item' returns the first matching node node.attribute('foo') returns the attribute named foo node.attribute('foo').value returns...

git name-rev --tags Note The more commonly used git describe command will return the last tag before a commit, git name-rev the next tag after the commit...

...jQuery (but before jquery-ujs): whitelisted = (url) -> for domain in ["http://trusted.host/", "https://another.trusted.host/"] return true if url.indexOf(domain) == 0 false $.ajaxPrefilter (options) -> if whitelisted(options.url) options.crossDomain = false

The attached download_helpers.rb provides a download_link method for your Capybara tests. It returns a hash describing the download's response: details = download_link('Download report') details[:disposition] # => 'attachment...

foo bar baz Hello Universe without :scope A simple document.body.querySelectorAll('div') will return a NodeList with 5 items, i.e. all 5 divs from above. with :scope Using document.body.querySelectorAll...

...secret folder with its contents. def migrate! correct_store_path = Pathname.new(new_store_dir) return if correct_store_path.directory? # already moved if the directory exists, nothing to do parent_path = correct_store_path.parent # this...

...path like "./foo.coffee". // The call to "substring" removes the "./" prefix. let preparePath = function(filePath) { return filePath.substring(2); }; modelFiles = require.context('js/models', true, /\.(js|coffee)$/); for(let filePath of modelFiles.keys()) { import(`js/models...

...callback this list might help you to fix your code afterwards: attribute_changed? will return true in the after_save callback and false in the after_commit callback. Use something...

...write something similar using jQuery.grep. let classes = Array.from($element.prop('classList')) let existingModifiers = classes.filter(className => { return className.match(/^is-/) }) $layout.removeClass(existingModifiers.join(' ')) Note that classList is native DOM API and returns a DOMTokenList...

...read: forever) you may pass a function that disects an element's class, and returns a string that will then be removed through the "classic" string approach. It's a...

...Summary ---------------------------- So, what's the final verdict on those 7 closure-like entities? "return" returns from closure True closure? or declaring context...? Arity check? --------------- ----------------------------- ------------------- 1. block (called with yield) N...

...block (&b => f(&b) => yield) N declaring no 3. block (&b => b.call) Y except return declaring warn on too few 4. Proc.new Y except return declaring warn on too few...

...into your ~/.config/awesome/rc.lua. It supplies two methods: execute_command will run a command and return its output. Multiple lines will be joined into one line. The code is from the...

...method that takes a command to run and a timeout in seconds. It'll return an object which contains a widget that you can put into your panel. ^

If you do not provide a block to find_each, it will return an Enumerator for chaining with other methods: Person.find_each.with_index do |person, index| person.award_trophy(index...

...in mind that their syntax is a bit different. UnderscoreJS In UnderscoreJS, methods always return a value: x = [1, 2, 2] _.uniq(x) // => [1, 2] _(x).uniq() // => [1, 2]

...chain, and call value() to terminate the chain. _.chain(x).uniq().map(function(i) { return i + 10 }).reverse().value() // => [12, 11] LoDash In LoDash, methods called from _ (like _.uniq) will...

var languageString = navigator.language || navigator.userLanguage || ''; var language = languageString.split(/[_-]/)[0]).toLowerCase(); switch (language) { case 'de': return "/de/"; case 'en': return "/en/"; default: return "/en/"; } })(); Note that old IEs support only navigator.userLanguage...

...which returns the regional setting of the operating system. Fallback For users without JavaScript, you may want to redirect them to your default locale. Do that by adding a meta...

...called an “inversion of control”. A function that accepts a callback instead of a return value is saying, “Don’t call me, I’ll call you.”. Promises un-invert the...

...Edge, there are polyfills for Internet Explorer. Usage: Usage Assume this piece of code returns a promise: api.get('pages') // => Promise You may now chain function calls to the promise using...