dsherret

/**
 * Ensure Public API Has Tests
 * ---------------------------
 * This demonstrates analyzing code to find methods and properties from the public
 * api that don't appear in the tests.
 * 
 * This is a very basic implementation... a better implementation would examine more
 * aspects of the code (ex. are the return values properly checked?) and report
 * statistics about the tests that possibly indicate how they could be improved (ex.
 * "this test has a lot of overlap with these other tests"). The goal would be to

bvaughn

const createLogger = (backgroundColor, color) => {
  const logger = (message, ...args) => {
    if (logger.enabled === false) {
      return;
    }

    console.groupCollapsed(
      `%c${message}`,
      `background-color: ${backgroundColor}; color: ${color}; padding: 2px 4px;`,
      ...args

aphyr

#!/bin/bash

# Args: input video file, start time in HH:MM:SS, duration in seconds, output
# gif file.

# Tmpdir
rm -rf /tmp/video2gif
mkdir /tmp/video2gif

mplayer -nosub -ao null -ss "$2" -endpos "$3" "$1" -vo jpeg:outdir=/tmp/video2gif:quality=100

shrunyan

const puppeteer = require('puppeteer')
const express = require('express')
const querystring = require('querystring')
const server = express()

/**
 * Screenshot a url
 * e.g. /screenshot?url=https://www.npmjs.com&width=800&height=600
 */
server.get('/screenshot', async (req, res) => {

pnc

#!/bin/bash

set -e

CONTENTS=$(tesseract -c language_model_penalty_non_dict_word=0.8 --tessdata-dir /usr/local/share/tessdata/ "$1" stdout -l eng | xml esc)

hex=$((cat <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">

drakeguan

#!/bin/bash

ffmpeg -y -i "$f" -vn -c:a libfdk_aac -b:a 128k "audio/$(basename $f .mp4).m4a"
afconvert -f caff -d opus -b 8000 "audio/$(basename $f .mp4).m4a" "opus/$(basename $f .mp4).caf"

max-mapper

{"help": "https://catalog.data.gov/api/3/action/help_show?name=package_search", "success": true, "result": {"count": 48, "sort": "views_recent desc", "facets": {}, "results": [{"license_title": "License not specified", "maintainer": "New Media", "relationships_as_object": [], "private": false, "maintainer_email": "newmedia@whitehouse.gov", "num_tags": 5, "id": "59694770-b6b6-4ae0-a4b9-4ae69c0be2f6", "metadata_created": "2016-07-02T10:06:26.199575", "metadata_modified": "2016-07-02T10:06:26.199575", "author": null, "author_email": null, "state": "active", "version": null, "creator_user_id": "47303a9e-1187-4290-85a3-1fc02dc49e4a", "type": "dataset", "resources": [{"cache_last_updated": null, "package_id": "59694770-b6b6-4ae0-a4b9-4ae69c0be2f6", "webstore_last_updated": null, "id": "3a8a0ad1-19e7-4153-bb2f-d70cf88aaaf8", "size": null, "state": "active", "hash": "", "description": "", "format": "CSV", "tracking_summary": {"total": 32, "recent": 1}, "last_modified": null, "url_type": null, "no_real_name": "True", 

garybernhardt

#!/usr/bin/env ruby

require 'base64'
require 'nokogiri'
require 'uri'

def main
  html = Nokogiri::HTML($stdin.read)
  inline_all_images(html)
  inline_all_css(html)

garybernhardt

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

andymatuschak

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,