Code files

Chapter01/debugging-with-devtools/app/future.js

@@ -0,0 +1,3 @@
+module.exports = (age, gap) => {
+  return `In ${gap} years you will be ${Number(age) + gap}<br>`
+}

Chapter01/debugging-with-devtools/app/index.js

@@ -0,0 +1,10 @@
+const express = require('express')
+const app = express()
+const past = require('./past')
+const future = require('./future')
+
+app.get('/:age', (req, res) => {
+  res.send(past(req.params.age, 10) + future(req.params.future, 10))
+})
+
+app.listen(3000)

Chapter01/debugging-with-devtools/app/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.2"
+  }
+}

Chapter01/debugging-with-devtools/app/past.js

@@ -0,0 +1,3 @@
+module.exports = (age, gap) => {
+  return `${gap} years ago you were ${Number(age) - gap}<br>`
+}

Chapter01/enabling-core-debug-logs/app/index.js

@@ -0,0 +1,11 @@
+const express = require('express')
+const app = express()
+
+app.get('/', (req, res) => res.send('hey'))
+
+
+setTimeout(function myTimeout() { 
+   console.log('I waited for you.')
+}, 100)
+
+app.listen(3000)

Chapter01/enabling-core-debug-logs/app/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.0"
+  }
+}

Chapter01/enabling-core-debug-logs/instrumented-app/index.js

@@ -0,0 +1,16 @@
+const util = require('util')
+const express = require('express')
+const debug = util.debuglog('my-app')
+const app = express()
+
+app.get('/', (req, res) => {
+  debug('incoming request on /', req.route)
+  res.send('hey')
+})
+
+setTimeout(function myTimeout() { 
+   debug('timeout complete')
+   console.log('I waited for you.')
+}, 100)
+
+app.listen(3000)

Chapter01/enabling-core-debug-logs/instrumented-app/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.0"
+  }
+}

Chapter01/enabling-debug-logs/app/index.js

@@ -0,0 +1,13 @@
+const express = require('express')
+const app = express()
+const stylus = require('stylus')
+
+app.get('/some.css', (req, res) => {
+  const css = stylus(`
+    body
+      color:black
+  `).render()
+  res.send(css)
+})
+
+app.listen(3000)

Chapter01/enabling-debug-logs/app/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.0",
+    "stylus": "^0.54.5"
+  }
+}

Chapter01/enabling-debug-logs/instrumented-app/index.js

@@ -0,0 +1,15 @@
+const express = require('express')
+const app = express()
+const stylus = require('stylus')
+const debug = require('debug')('my-app')
+
+app.get('/some.css', (req, res) => {
+  debug('css requested')
+  const css = stylus(`
+    body
+      color:black
+  `).render()
+  res.send(css)
+})
+
+app.listen(3000)

Chapter01/enabling-debug-logs/instrumented-app/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "debug": "^2.6.2",
+    "express": "^4.15.0",
+    "stylus": "^0.54.5"
+  }
+}

Chapter01/enabling-debug-logs/logging-app/index.js

@@ -0,0 +1,13 @@
+const express = require('express')
+const app = express()
+const stylus = require('stylus')
+
+app.get('/some.css', (req, res) => {
+  const css = stylus(`
+    body
+      color:black
+  `).render()
+  res.send(css)
+})
+
+app.listen(3000)

Chapter01/enabling-debug-logs/logging-app/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "dev": "node index.js",
+    "prod": "node -r pino-debug index.js"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.0",
+    "pino-debug": "^1.0.3",
+    "stylus": "^0.54.5"
+  }
+}

Chapter01/enabling-debug-logs/logging-app/package.json.save

@@ -0,0 +1,18 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "start": "node 
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.0",
+    "pino-debug": "^1.0.2",
+    "stylus": "^0.54.5"
+  }
+}

Chapter01/enhancing-stack-traces/app/content.js

@@ -0,0 +1,5 @@
+function content (opts, c = 20) {
+  return --c ? content(opts, c) : opts.ohoh
+}
+
+module.exports = content

Chapter01/enhancing-stack-traces/app/index.js

@@ -0,0 +1,7 @@
+const express = require('express')
+const routes = require('./routes')
+const app = express()
+
+app.use(routes)
+
+app.listen(3000)

Chapter01/enhancing-stack-traces/app/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.2"
+  }
+}

Chapter01/enhancing-stack-traces/app/routes.js

@@ -0,0 +1,9 @@
+const content = require('./content')
+const {Router} = require('express')
+const router = new Router()
+
+router.get('/', (req, res) => {
+  res.send(content())
+})
+
+module.exports = router

Chapter01/enhancing-stack-traces/async-stack-app/content.js

@@ -0,0 +1,9 @@
+function content (opts, c = 20) {
+  function produce (cb) {
+    if (--c) setTimeout(produce, 10, cb)
+    cb(null, opts.ohoh)
+  }
+  return produce
+}
+
+module.exports = content

Chapter01/enhancing-stack-traces/async-stack-app/index.js

@@ -0,0 +1,10 @@
+if (process.env.NODE_ENV !== 'production') {
+  require('longjohn')
+}
+const express = require('express')
+const routes = require('./routes')
+const app = express()
+
+app.use(routes)
+
+app.listen(3000)

Chapter01/enhancing-stack-traces/async-stack-app/package.json

@@ -0,0 +1,18 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.2"
+  },
+  "devDependencies": {
+    "longjohn": "^0.2.12"
+  }
+}

Chapter01/enhancing-stack-traces/async-stack-app/routes.js

@@ -0,0 +1,15 @@
+const content = require('./content')
+const {Router} = require('express')
+const router = new Router()
+
+router.get('/', (req, res) => {
+  content()((err, html) => { 
+    if (err) {
+      res.send(500)
+      return
+    } 
+    res.send(html)
+  })
+})
+
+module.exports = router

Chapter01/enhancing-stack-traces/infinite-stack-in-dev-app/content.js

@@ -0,0 +1,5 @@
+function content (opts, c = 20) {
+  return --c ? content(opts, c) : opts.ohoh
+}
+
+module.exports = content

Chapter01/enhancing-stack-traces/infinite-stack-in-dev-app/index.js

@@ -0,0 +1,10 @@
+if (process.env.NODE_ENV !== 'production') {
+  Error.stackTraceLimit = Infinity
+}
+const express = require('express')
+const routes = require('./routes')
+const app = express()
+
+app.use(routes)
+
+app.listen(3000)

Chapter01/enhancing-stack-traces/infinite-stack-in-dev-app/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "express": "^4.15.2"
+  }
+}

Chapter01/enhancing-stack-traces/infinite-stack-in-dev-app/routes.js

@@ -0,0 +1,9 @@
+const content = require('./content')
+const {Router} = require('express')
+const router = new Router()
+
+router.get('/', (req, res) => {
+  res.send(content())
+})
+
+module.exports = router

Chapter01/enhancing-stack-traces/pretty-stack-app/content.js

@@ -0,0 +1,5 @@
+function content (opts, c = 20) {
+  return --c ? content(opts, c) : opts.ohoh
+}
+
+module.exports = content

Chapter01/enhancing-stack-traces/pretty-stack-app/index.js

@@ -0,0 +1,8 @@
+require('cute-stack')()
+const express = require('express')
+const routes = require('./routes')
+const app = express()
+
+app.use(routes)
+
+app.listen(3000)

Chapter01/enhancing-stack-traces/pretty-stack-app/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "app",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "cute-stack": "^1.4.3",
+    "express": "^4.15.2"
+  },
+  "devDependencies": {}
+}

Chapter01/enhancing-stack-traces/pretty-stack-app/routes.js

@@ -0,0 +1,9 @@
+const content = require('./content')
+const {Router} = require('express')
+const router = new Router()
+
+router.get('/', (req, res) => {
+  res.send(content())
+})
+
+module.exports = router

Chapter02/installing-dependencies/hsl-to-hex/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  }
+}

Chapter02/installing-dependencies/installing-development-dependencies/hsl-to-hex/package.json

@@ -0,0 +1,25 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8"
+  }
+}

Chapter02/installing-dependencies/using-npm-run-scripts/hsl-to-hex/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "npm run lint",
+    "lint": "standard"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8"
+  }
+}

Chapter02/publishing-a-module/decentralized-publishing/hsl-to-hex/.gitignore

@@ -0,0 +1,2 @@
+node_modules
+*.log

Chapter02/publishing-a-module/decentralized-publishing/hsl-to-hex/example.js

@@ -0,0 +1,6 @@
+var hsl = require('./')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282

Chapter02/publishing-a-module/decentralized-publishing/hsl-to-hex/index.js

@@ -0,0 +1,66 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+var debug = require('debug')('hsl-to-hex')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  debug('ensuring ' + val + ' is no more than ' + n)
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  debug('ensuring ' + val + ' is no less than ' + n)
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  debug('resolving ' + val + ' within the 0-359 range')
+
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  debug('calculating hex for hue: ' + hue + ' saturation: ' + saturation + ' luminosity: ' + luminosity)
+
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/publishing-a-module/decentralized-publishing/hsl-to-hex/package.json

@@ -0,0 +1,33 @@
+{
+  "name": "@davidmarkclements/hsl-to-hex",
+  "version": "1.0.1",
+  "main": "index.js",
+  "scripts": {
+    "check": "npm ls && npm test",
+    "test": "npm run lint && tap --cov test",
+    "lint": "standard",
+    "prepublish": "npm run check && ./publish-dep.sh"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "Convert HSL colors to RGB colors in hex format.",
+  "dependencies": {
+    "debug": "^2.2.0",
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8",
+    "tap": "^5.7.0"
+  },
+  "directories": {
+    "test": "test"
+  }
+}

Chapter02/publishing-a-module/decentralized-publishing/hsl-to-hex/publish-dep.sh

@@ -0,0 +1,50 @@
+#! /bin/sh
+
+# 400 - Missing hash and/or peer_id
+# 403 - Not allowed
+# 413 - Too big
+# 200 - Ok!
+
+
+if echo $npm_config_argv | grep -q "install"; then
+  echo "Running at install step, skipping"
+else
+  if ipfs &>/dev/null; then
+    echo "## Publishing dependency"
+
+    mv node_modules .node_modules 2>/dev/null
+
+    HASH=$(ipfs add . -r | tail -n 1 | cut -d ' ' -f 2)
+
+    mv .node_modules node_modules 2>/dev/null
+
+    echo "Published as $HASH"
+
+    PEER=$(ipfs id --format '<id>')
+
+    if [ -f ~/.stay/nodes.json ]; then
+      cat ~/.stay/nodes.json | jq -rc '.[]' | while read host; do
+        address="$host/api/pin/add/$HASH/$PEER"
+        status=$(curl -X POST --silent $address)
+        case "$status" in
+          "400")  echo "$host - Application Error: Missing the hash and/or peer_id"
+            ;;
+          "403")  echo  "$host - You do not have access to pinning at this node"
+            ;;
+          "413")  echo  "$host - The module was too big to pin!"
+            ;;
+          "200") echo  "$host - Pinned!"
+            ;;
+          *) echo "Weird status code $status for $host"
+            ;;
+        esac
+      done
+    else
+      echo "You don't have any saved nodes in ~/.stay/nodes.json, skip pinning"
+    fi
+  else
+    echo "## Could not publish dependency to IPFS, doing the good'ol 'fetch from npm registry' way"
+    echo "Either 'ipfs' doesn't exists in PATH or you haven't run 'ipfs daemon' before running the command"
+    exit 0
+  fi
+fi

Chapter02/publishing-a-module/decentralized-publishing/hsl-to-hex/readme.md

@@ -0,0 +1,31 @@
+# hsl-to-hex
+
+Convert HSL colors to RGB colors in hex format.
+
+## Install 
+
+```sh
+npm install --save @davidmarkclements/hsl-to-hex
+```
+ 
+## API
+
+```
+require('hsl-to-hex') => Function
+hsl(hue, saturation, luminosity)` => String
+```
+
+## Example
+
+```js
+var hsl = require('hsl-to-hex')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282
+```
+
+## License
+
+ISC

Chapter02/publishing-a-module/decentralized-publishing/hsl-to-hex/test/index.js

@@ -0,0 +1,74 @@
+var hsl = require('../')
+var test = require('tap').test
+
+test('pure white', function (assert) {
+  var expected = '#ffffff'
+  var actual = hsl(0, 100, 100)
+  var it = 'max saturation and luminosity should return pure white'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('medium gray', function (assert) {
+  var expected = '#808080'
+  var actual = hsl(0, 0, 50)
+  var it = '0% saturation, 50% luminosity should be medium gray'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - red', function (assert) {
+  var expected = '#ff0000'
+  var actual = hsl(0, 100, 50)
+  var it = '0deg should be red'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - blue', function (assert) {
+  var expected = '#0000ff'
+  var actual = hsl(240, 100, 50)
+  var it = '240deg should be blue'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - cyan', function (assert) {
+  var expected = '#00ffff'
+  var actual = hsl(180, 100, 50)
+  var it = '180deg should be cyan'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree overflow', function (assert) {
+  var expected = hsl(1, 100, 50)
+  var actual = hsl(361, 100, 50)
+  var it = '361deg should be the same as 1deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree underflow', function (assert) {
+  var expected = hsl(-1, 100, 50)
+  var actual = hsl(359, 100, 50)
+  var it = '-1deg should be the same as 359deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('max constraint', function (assert) {
+  var expected = hsl(0, 101, 50)
+  var actual = hsl(0, 100, 50)
+  var it = '101% should be the same as 100%'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('min constraint', function (assert) {
+  var expected = hsl(0, -1, 50)
+  var actual = hsl(0, 0, 50)
+  var it = '-1% should be the same as 0%'
+  assert.is(actual, expected, it)
+  assert.end()
+})

Chapter02/publishing-a-module/decentralized-publishing/stay-play/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "stay-play",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "David Mark Clements",
+  "license": "MIT"
+}

Chapter02/publishing-a-module/hsl-to-hex/.gitignore

@@ -0,0 +1,2 @@
+node_modules
+*.log

Chapter02/publishing-a-module/hsl-to-hex/example.js

@@ -0,0 +1,6 @@
+var hsl = require('./')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282

Chapter02/publishing-a-module/hsl-to-hex/index.js

@@ -0,0 +1,59 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/publishing-a-module/hsl-to-hex/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "@davidmarkclements/hsl-to-hex",
+  "version": "1.0.1",
+  "main": "index.js",
+  "scripts": {
+    "test": "npm run lint && tap --cov test",
+    "lint": "standard"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "Convert HSL colors to RGB colors in hex format.",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8",
+    "tap": "^5.7.0"
+  },
+  "directories": {
+    "test": "test"
+  }
+}

Chapter02/publishing-a-module/hsl-to-hex/readme.md

@@ -0,0 +1,32 @@
+# hsl-to-hex
+
+Convert HSL colors to RGB colors in hex format.
+
+## Install 
+
+```sh
+npm install --save @davidmarkclements/hsl-to-hex
+```
+ 
+## API
+
+```
+require('hsl-to-hex') => Function
+hsl(hue, saturation, luminosity)` => String
+```
+
+## Example
+
+```js
+var hsl = require('hsl-to-hex')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282
+
+```
+
+## License
+
+ISC

Chapter02/publishing-a-module/hsl-to-hex/test/index.js

@@ -0,0 +1,74 @@
+var hsl = require('../')
+var test = require('tap').test
+
+test('pure white', function (assert) {
+  var expected = '#ffffff'
+  var actual = hsl(0, 100, 100)
+  var it = 'max saturation and luminosity should return pure white'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('medium gray', function (assert) {
+  var expected = '#808080'
+  var actual = hsl(0, 0, 50)
+  var it = '0% saturation, 50% luminosity should be medium gray'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - red', function (assert) {
+  var expected = '#ff0000'
+  var actual = hsl(0, 100, 50)
+  var it = '0deg should be red'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - blue', function (assert) {
+  var expected = '#0000ff'
+  var actual = hsl(240, 100, 50)
+  var it = '240deg should be blue'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - cyan', function (assert) {
+  var expected = '#00ffff'
+  var actual = hsl(180, 100, 50)
+  var it = '180deg should be cyan'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree overflow', function (assert) {
+  var expected = hsl(1, 100, 50)
+  var actual = hsl(361, 100, 50)
+  var it = '361deg should be the same as 1deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree underflow', function (assert) {
+  var expected = hsl(-1, 100, 50)
+  var actual = hsl(359, 100, 50)
+  var it = '-1deg should be the same as 359deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('max constraint', function (assert) {
+  var expected = hsl(0, 101, 50)
+  var actual = hsl(0, 100, 50)
+  var it = '101% should be the same as 100%'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('min constraint', function (assert) {
+  var expected = hsl(0, -1, 50)
+  var actual = hsl(0, 0, 50)
+  var it = '-1% should be the same as 0%'
+  assert.is(actual, expected, it)
+  assert.end()
+})

Chapter02/publishing-a-module/listing-installed-modules/hsl-to-hex/.gitignore

@@ -0,0 +1,2 @@
+node_modules
+*.log

Chapter02/publishing-a-module/listing-installed-modules/hsl-to-hex/example.js

@@ -0,0 +1,6 @@
+var hsl = require('./')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282

Chapter02/publishing-a-module/listing-installed-modules/hsl-to-hex/index.js

@@ -0,0 +1,66 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+var debug = require('debug')('hsl-to-hex')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  debug('ensuring ' + val + ' is no more than ' + n)
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  debug('ensuring ' + val + ' is no less than ' + n)
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  debug('resolving ' + val + ' within the 0-359 range')
+
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  debug('calculating hex for hue: ' + hue + ' saturation: ' + saturation + ' luminosity: ' + luminosity)
+
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/publishing-a-module/listing-installed-modules/hsl-to-hex/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "@davidmarkclements/hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "npm run lint && tap --cov test",
+    "lint": "standard"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "Convert HSL colors to RGB colors in hex format.",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8",
+    "tap": "^5.7.0"
+  },
+  "directories": {
+    "test": "test"
+  }
+}

Chapter02/publishing-a-module/listing-installed-modules/hsl-to-hex/readme.md

@@ -0,0 +1,31 @@
+# hsl-to-hex
+
+Convert HSL colors to RGB colors in hex format.
+
+## Install 
+
+```sh
+npm install --save @davidmarkclements/hsl-to-hex
+```
+ 
+## API
+
+```
+require('hsl-to-hex') => Function
+hsl(hue, saturation, luminosity)` => String
+```
+
+## Example
+
+```js
+var hsl = require('hsl-to-hex')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282
+```
+
+## License
+
+ISC

Chapter02/publishing-a-module/listing-installed-modules/hsl-to-hex/test/index.js

@@ -0,0 +1,74 @@
+var hsl = require('../')
+var test = require('tap').test
+
+test('pure white', function (assert) {
+  var expected = '#ffffff'
+  var actual = hsl(0, 100, 100)
+  var it = 'max saturation and luminosity should return pure white'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('medium gray', function (assert) {
+  var expected = '#808080'
+  var actual = hsl(0, 0, 50)
+  var it = '0% saturation, 50% luminosity should be medium gray'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - red', function (assert) {
+  var expected = '#ff0000'
+  var actual = hsl(0, 100, 50)
+  var it = '0deg should be red'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - blue', function (assert) {
+  var expected = '#0000ff'
+  var actual = hsl(240, 100, 50)
+  var it = '240deg should be blue'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - cyan', function (assert) {
+  var expected = '#00ffff'
+  var actual = hsl(180, 100, 50)
+  var it = '180deg should be cyan'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree overflow', function (assert) {
+  var expected = hsl(1, 100, 50)
+  var actual = hsl(361, 100, 50)
+  var it = '361deg should be the same as 1deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree underflow', function (assert) {
+  var expected = hsl(-1, 100, 50)
+  var actual = hsl(359, 100, 50)
+  var it = '-1deg should be the same as 359deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('max constraint', function (assert) {
+  var expected = hsl(0, 101, 50)
+  var actual = hsl(0, 100, 50)
+  var it = '101% should be the same as 100%'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('min constraint', function (assert) {
+  var expected = hsl(0, -1, 50)
+  var actual = hsl(0, 0, 50)
+  var it = '-1% should be the same as 0%'
+  assert.is(actual, expected, it)
+  assert.end()
+})

Chapter02/publishing-a-module/prepublish/hsl-to-hex/.gitignore

@@ -0,0 +1,2 @@
+node_modules
+*.log

Chapter02/publishing-a-module/prepublish/hsl-to-hex/example.js

@@ -0,0 +1,6 @@
+var hsl = require('./')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282

Chapter02/publishing-a-module/prepublish/hsl-to-hex/index.js

@@ -0,0 +1,66 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+var debug = require('debug')('hsl-to-hex')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  debug('ensuring ' + val + ' is no more than ' + n)
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  debug('ensuring ' + val + ' is no less than ' + n)
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  debug('resolving ' + val + ' within the 0-359 range')
+
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  debug('calculating hex for hue: ' + hue + ' saturation: ' + saturation + ' luminosity: ' + luminosity)
+
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/publishing-a-module/prepublish/hsl-to-hex/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "@davidmarkclements/hsl-to-hex",
+  "version": "1.0.1",
+  "main": "index.js",
+  "scripts": {
+    "prepublish": "npm ls && npm test",
+    "test": "npm run lint && tap --cov test",
+    "lint": "standard"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "Convert HSL colors to RGB colors in hex format.",
+  "dependencies": {
+    "debug": "^2.2.0",
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8",
+    "tap": "^5.7.0"
+  },
+  "directories": {
+    "test": "test"
+  }
+}

Chapter02/publishing-a-module/prepublish/hsl-to-hex/readme.md

@@ -0,0 +1,31 @@
+# hsl-to-hex
+
+Convert HSL colors to RGB colors in hex format.
+
+## Install 
+
+```sh
+npm install --save @davidmarkclements/hsl-to-hex
+```
+ 
+## API
+
+```
+require('hsl-to-hex') => Function
+hsl(hue, saturation, luminosity)` => String
+```
+
+## Example
+
+```js
+var hsl = require('hsl-to-hex')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282
+```
+
+## License
+
+ISC

Chapter02/publishing-a-module/prepublish/hsl-to-hex/test/index.js

@@ -0,0 +1,74 @@
+var hsl = require('../')
+var test = require('tap').test
+
+test('pure white', function (assert) {
+  var expected = '#ffffff'
+  var actual = hsl(0, 100, 100)
+  var it = 'max saturation and luminosity should return pure white'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('medium gray', function (assert) {
+  var expected = '#808080'
+  var actual = hsl(0, 0, 50)
+  var it = '0% saturation, 50% luminosity should be medium gray'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - red', function (assert) {
+  var expected = '#ff0000'
+  var actual = hsl(0, 100, 50)
+  var it = '0deg should be red'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - blue', function (assert) {
+  var expected = '#0000ff'
+  var actual = hsl(240, 100, 50)
+  var it = '240deg should be blue'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - cyan', function (assert) {
+  var expected = '#00ffff'
+  var actual = hsl(180, 100, 50)
+  var it = '180deg should be cyan'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree overflow', function (assert) {
+  var expected = hsl(1, 100, 50)
+  var actual = hsl(361, 100, 50)
+  var it = '361deg should be the same as 1deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree underflow', function (assert) {
+  var expected = hsl(-1, 100, 50)
+  var actual = hsl(359, 100, 50)
+  var it = '-1deg should be the same as 359deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('max constraint', function (assert) {
+  var expected = hsl(0, 101, 50)
+  var actual = hsl(0, 100, 50)
+  var it = '101% should be the same as 100%'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('min constraint', function (assert) {
+  var expected = hsl(0, -1, 50)
+  var actual = hsl(0, 0, 50)
+  var it = '-1% should be the same as 0%'
+  assert.is(actual, expected, it)
+  assert.end()
+})

Chapter02/scaffolding-a-module/hsl-to-hex/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": ""
+}

Chapter02/scaffolding-a-module/reinitializing/hsl-to-hex/.gitignore

@@ -0,0 +1,2 @@
+node_modules
+*.log

Chapter02/scaffolding-a-module/reinitializing/hsl-to-hex/package.json

@@ -0,0 +1,19 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": ""
+}

Chapter02/using-a-private-repository/scope-registries/hsl-to-hex/.gitignore

@@ -0,0 +1,2 @@
+node_modules
+*.log

Chapter02/using-a-private-repository/scope-registries/hsl-to-hex/example.js

@@ -0,0 +1,6 @@
+var hsl = require('./')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282

Chapter02/using-a-private-repository/scope-registries/hsl-to-hex/index.js

@@ -0,0 +1,66 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+var debug = require('debug')('hsl-to-hex')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  debug('ensuring ' + val + ' is no more than ' + n)
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  debug('ensuring ' + val + ' is no less than ' + n)
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  debug('resolving ' + val + ' within the 0-359 range')
+
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  debug('calculating hex for hue: ' + hue + ' saturation: ' + saturation + ' luminosity: ' + luminosity)
+
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/using-a-private-repository/scope-registries/hsl-to-hex/package.json

@@ -0,0 +1,33 @@
+{
+  "name": "@ncb/hsl-to-hex",
+  "version": "1.0.1",
+  "main": "index.js",
+  "scripts": {
+    "check": "npm ls && npm test",
+    "test": "npm run lint && tap --cov test",
+    "lint": "standard",
+    "prepublish": "npm run check && ./publish-dep.sh"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "Convert HSL colors to RGB colors in hex format.",
+  "dependencies": {
+    "debug": "^2.2.0",
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8",
+    "tap": "^5.7.0"
+  },
+  "directories": {
+    "test": "test"
+  }
+}

Chapter02/using-a-private-repository/scope-registries/hsl-to-hex/publish-dep.sh

@@ -0,0 +1,50 @@
+#! /bin/sh
+
+# 400 - Missing hash and/or peer_id
+# 403 - Not allowed
+# 413 - Too big
+# 200 - Ok!
+
+
+if echo $npm_config_argv | grep -q "install"; then
+  echo "Running at install step, skipping"
+else
+  if ipfs &>/dev/null; then
+    echo "## Publishing dependency"
+
+    mv node_modules .node_modules 2>/dev/null
+
+    HASH=$(ipfs add . -r | tail -n 1 | cut -d ' ' -f 2)
+
+    mv .node_modules node_modules 2>/dev/null
+
+    echo "Published as $HASH"
+
+    PEER=$(ipfs id --format '<id>')
+
+    if [ -f ~/.stay/nodes.json ]; then
+      cat ~/.stay/nodes.json | jq -rc '.[]' | while read host; do
+        address="$host/api/pin/add/$HASH/$PEER"
+        status=$(curl -X POST --silent $address)
+        case "$status" in
+          "400")  echo "$host - Application Error: Missing the hash and/or peer_id"
+            ;;
+          "403")  echo  "$host - You do not have access to pinning at this node"
+            ;;
+          "413")  echo  "$host - The module was too big to pin!"
+            ;;
+          "200") echo  "$host - Pinned!"
+            ;;
+          *) echo "Weird status code $status for $host"
+            ;;
+        esac
+      done
+    else
+      echo "You don't have any saved nodes in ~/.stay/nodes.json, skip pinning"
+    fi
+  else
+    echo "## Could not publish dependency to IPFS, doing the good'ol 'fetch from npm registry' way"
+    echo "Either 'ipfs' doesn't exists in PATH or you haven't run 'ipfs daemon' before running the command"
+    exit 0
+  fi
+fi

Chapter02/using-a-private-repository/scope-registries/hsl-to-hex/readme.md

@@ -0,0 +1,31 @@
+# hsl-to-hex
+
+Convert HSL colors to RGB colors in hex format.
+
+## Install 
+
+```sh
+npm install --save @davidmarkclements/hsl-to-hex
+```
+ 
+## API
+
+```
+require('hsl-to-hex') => Function
+hsl(hue, saturation, luminosity)` => String
+```
+
+## Example
+
+```js
+var hsl = require('hsl-to-hex')
+var hue = 133
+var saturation = 40
+var luminosity = 60
+var hex = hsl(hue, saturation, luminosity)
+console.log(hex) // #70c282
+```
+
+## License
+
+ISC

Chapter02/using-a-private-repository/scope-registries/hsl-to-hex/test/index.js

@@ -0,0 +1,74 @@
+var hsl = require('../')
+var test = require('tap').test
+
+test('pure white', function (assert) {
+  var expected = '#ffffff'
+  var actual = hsl(0, 100, 100)
+  var it = 'max saturation and luminosity should return pure white'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('medium gray', function (assert) {
+  var expected = '#808080'
+  var actual = hsl(0, 0, 50)
+  var it = '0% saturation, 50% luminosity should be medium gray'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - red', function (assert) {
+  var expected = '#ff0000'
+  var actual = hsl(0, 100, 50)
+  var it = '0deg should be red'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - blue', function (assert) {
+  var expected = '#0000ff'
+  var actual = hsl(240, 100, 50)
+  var it = '240deg should be blue'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - cyan', function (assert) {
+  var expected = '#00ffff'
+  var actual = hsl(180, 100, 50)
+  var it = '180deg should be cyan'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree overflow', function (assert) {
+  var expected = hsl(1, 100, 50)
+  var actual = hsl(361, 100, 50)
+  var it = '361deg should be the same as 1deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree underflow', function (assert) {
+  var expected = hsl(-1, 100, 50)
+  var actual = hsl(359, 100, 50)
+  var it = '-1deg should be the same as 359deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('max constraint', function (assert) {
+  var expected = hsl(0, 101, 50)
+  var actual = hsl(0, 100, 50)
+  var it = '101% should be the same as 100%'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('min constraint', function (assert) {
+  var expected = hsl(0, -1, 50)
+  var actual = hsl(0, 0, 50)
+  var it = '-1% should be the same as 0%'
+  assert.is(actual, expected, it)
+  assert.end()
+})

Chapter02/writing-module-code/adding-tests/hsl-to-hex/index.js

@@ -0,0 +1,59 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/writing-module-code/adding-tests/hsl-to-hex/package.json

@@ -0,0 +1,27 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "npm run lint && tap --cov test",
+    "lint": "standard"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8",
+    "tap": "^5.7.0"
+  }
+}

Chapter02/writing-module-code/adding-tests/hsl-to-hex/test/index.js

@@ -0,0 +1,74 @@
+var hsl = require('../')
+var test = require('tap').test
+
+test('pure white', function (assert) {
+  var expected = '#ffffff'
+  var actual = hsl(0, 100, 100)
+  var it = 'max saturation and luminosity should return pure white'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('medium gray', function (assert) {
+  var expected = '#808080'
+  var actual = hsl(0, 0, 50)
+  var it = '0% saturation, 50% luminosity should be medium gray'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - red', function (assert) {
+  var expected = '#ff0000'
+  var actual = hsl(0, 100, 50)
+  var it = '0deg should be red'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - blue', function (assert) {
+  var expected = '#0000ff'
+  var actual = hsl(240, 100, 50)
+  var it = '240deg should be blue'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('hue - cyan', function (assert) {
+  var expected = '#00ffff'
+  var actual = hsl(180, 100, 50)
+  var it = '180deg should be cyan'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree overflow', function (assert) {
+  var expected = hsl(1, 100, 50)
+  var actual = hsl(361, 100, 50)
+  var it = '361deg should be the same as 1deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('degree underflow', function (assert) {
+  var expected = hsl(-1, 100, 50)
+  var actual = hsl(359, 100, 50)
+  var it = '-1deg should be the same as 359deg'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('max constraint', function (assert) {
+  var expected = hsl(0, 101, 50)
+  var actual = hsl(0, 100, 50)
+  var it = '101% should be the same as 100%'
+  assert.is(actual, expected, it)
+  assert.end()
+})
+
+test('min constraint', function (assert) {
+  var expected = hsl(0, -1, 50)
+  var actual = hsl(0, 0, 50)
+  var it = '-1% should be the same as 0%'
+  assert.is(actual, expected, it)
+  assert.end()
+})

Chapter02/writing-module-code/hsl-to-hex/index.js

@@ -0,0 +1,59 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/writing-module-code/hsl-to-hex/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "npm run lint",
+    "lint": "standard"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8"
+  }
+}

Chapter02/writing-module-code/modernizing-syntax/hsl-to-hex/index.js

@@ -0,0 +1,59 @@
+// In our case, there's only one dependency
+
+var toRgb = require('hsl-to-rgb-for-reals')
+
+// Typically all dependencies should be declared at the top of the file.
+
+// Now let's define an API for our module, we're taking hue, saturation and luminosity values and outputting a CSS compatible hex string.
+// Hue is in degrees, between 0 and 359. Since degrees a cyclical in nature, we'll support numbers greater than 359 or less than 0 by "spinning" them around until they fall within the 0 to 359 range.
+// Saturation and luminosity are both percentages, we'll represent these percentages with whole numbers between 0 and 100. For these numbers we'll need to enforce a maximum and a minimum, anything below 0 will become 0, anything above 100 will become 100.
+// Let's write some utility functions to handle this logic:
+
+function max (val, n) {
+  return (val > n) ? n : val
+}
+
+function min (val, n) {
+  return (val < n) ? n : val
+}
+
+function cycle (val) {
+  // for safety:
+  val = max(val, 1e7)
+  val = min(val, -1e7)
+  // cycle value:
+  while (val < 0) { val += 360 }
+  while (val > 359) { val -= 360 }
+  return val
+}
+
+// Now for the main piece, the `hsl` function:
+
+function hsl (hue, saturation, luminosity) {
+  // resolve degrees to 0 - 359 range
+  hue = cycle(hue)
+
+  // enforce constraints
+  saturation = min(max(saturation, 100), 0)
+  luminosity = min(max(luminosity, 100), 0)
+
+  // convert to 0 to 1 range used by hsl-to-rgb-for-reals
+  saturation /= 100
+  luminosity /= 100
+
+  // let hsl-to-rgb-for-reals do the hard work
+  var rgb = toRgb(hue, saturation, luminosity)
+
+  // convert each value in the returned RGB array
+  // to a 2 character hex value, join the array into
+  // a string, prefixed with a hash
+  return '#' + rgb
+    .map(function (n) {
+      return (256 + n).toString(16).substr(-2)
+    })
+    .join('')
+}
+
+// In order to make our code into a bona fide module we have to export it:
+
+module.exports = hsl

Chapter02/writing-module-code/modernizing-syntax/hsl-to-hex/package.json

@@ -0,0 +1,27 @@
+{
+  "name": "hsl-to-hex",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "npm run lint && tap --node-arg='--harmony-destructuring' --cov test",
+    "lint": "standard"
+  },
+  "author": "David Mark Clements",
+  "license": "ISC",
+  "repository": {
+    "type": "git",
+    "url": "git+ssh://git@github.com/davidmarkclements/hsl-to-hex.git"
+  },
+  "bugs": {
+    "url": "https://github.com/davidmarkclements/hsl-to-hex/issues"
+  },
+  "homepage": "https://github.com/davidmarkclements/hsl-to-hex#readme",
+  "description": "",
+  "dependencies": {
+    "hsl-to-rgb-for-reals": "^1.1.0"
+  },
+  "devDependencies": {
+    "standard": "^6.0.8",
+    "tap": "^5.7.0"
+  }
+}

Chapter02/writing-module-code/modernizing-syntax/hsl-to-hex/test/index.js

@@ -0,0 +1,90 @@
+const hsl = require('../')
+const {test} = require('tap')
+
+test('pure white', ({is, end}) => {
+  const expected = '#ffffff'
+  const actual = hsl(0, 100, 100)
+  const it = `
+    max saturation and luminosity should return pure white
+  `
+  is(actual, expected, it)
+  end()
+})
+
+test('medium gray', ({is, end}) => {
+  const expected = '#808080'
+  const actual = hsl(0, 0, 50)
+  const it = `
+    0% saturation, 50% luminosity should be medium gray
+  `
+  is(actual, expected, it)
+  end()
+})
+
+test('hue', ({is, end}) => {
+  {
+    const expected = '#ff0000'
+    const actual = hsl(0, 100, 50)
+    const it = `
+      0deg should be red
+    `
+    is(actual, expected, it)
+  }
+  {
+    const expected = '#0000ff'
+    const actual = hsl(240, 100, 50)
+    const it = `
+      240deg should be blue
+    `
+    is(actual, expected, it)
+  }
+  {
+    const expected = '#00ffff'
+    const actual = hsl(180, 100, 50)
+    const it = `
+      180deg should be cyan
+    `
+    is(actual, expected, it)
+  }
+  end()
+})
+
+test('degree overflow/underflow', ({is, end}) => {
+  {
+    const expected = hsl(1, 100, 50)
+    const actual = hsl(361, 100, 50)
+    const it = `
+      361deg should be the same as 1deg
+    `
+    is(actual, expected, it)
+  }
+  {
+    const expected = hsl(-1, 100, 50)
+    const actual = hsl(359, 100, 50)
+    const it = `
+      -1deg should be the same as 359deg
+    `
+    is(actual, expected, it)
+  }
+  end()
+})
+
+test('max constraint', ({is, end}) => {
+  {
+    const expected = hsl(0, 101, 50)
+    const actual = hsl(0, 100, 50)
+    const it = `
+      101% should be the same as 100%
+    `
+    is(actual, expected, it)
+  }
+  {
+    const expected = hsl(0, -1, 50)
+    const actual = hsl(0, 0, 50)
+    const it = `
+      -1% should be the same as 0%
+    `
+    is(actual, expected, it)
+  }
+  end()
+})

Chapter03/communicating-over-sockets/client.js

@@ -0,0 +1,16 @@
+'use strict'
+
+const net = require('net')
+
+const socket = net.connect(1337, 'localhost')
+const name = process.argv[2] || 'Dave'
+
+socket.write(name)
+
+socket.on('data', (data) => {
+  console.log(data.toString())
+})
+
+socket.on('close', () => {
+  console.log('-> disconnected by server')
+})

Chapter03/communicating-over-sockets/net-sockets-are-streams/client.js

@@ -0,0 +1,14 @@
+'use strict'
+
+const net = require('net')
+
+const socket = net.connect(1337)
+const name = process.argv[2] || 'Dave'
+
+socket.write(name)
+
+socket.pipe(process.stdout)
+
+socket.on('close', () => {
+  console.log('-> disconnected by server')
+})

Chapter03/communicating-over-sockets/net-sockets-are-streams/echo-client.js

@@ -0,0 +1,3 @@
+'use strict'
+
+process.stdin.pipe(require('net').connect(1338)).pipe(process.stdout)

Chapter03/communicating-over-sockets/net-sockets-are-streams/echo-server.js

@@ -0,0 +1,3 @@
+'use strict'
+
+require('net').createServer((socket) => socket.pipe(socket)).listen(1338)

Chapter03/communicating-over-sockets/net-sockets-are-streams/server.js

@@ -0,0 +1,13 @@
+'use strict'
+
+const net = require('net')
+
+net.createServer((socket) => {
+  console.log('-> client connected')
+  socket.once('data', name => {
+    socket.write(`Hi ${name}!`)
+  })
+  socket.on('close', () => {
+    console.log('-> client disconnected')
+  })
+}).listen(1337)

Chapter03/communicating-over-sockets/server.js

@@ -0,0 +1,13 @@
+'use strict'
+
+const net = require('net')
+
+net.createServer((socket) => {
+  console.log('-> client connected')
+  socket.on('data', name => {
+    socket.write(`Hi ${name}!`)
+  })
+  socket.on('close', () => {
+    console.log('-> client disconnected')
+  })
+}).listen(1337, 'localhost')

Chapter03/communicating-over-sockets/udp-sockets/client.js

@@ -0,0 +1,13 @@
+'use strict'
+
+const dgram = require('dgram')
+
+const socket = dgram.createSocket('udp4')
+const name = process.argv[2] || 'Dave'
+
+socket.bind(1400)
+socket.send(name, 1339)
+
+socket.on('message', (data) => {
+  console.log(data.toString())
+})

Chapter03/communicating-over-sockets/udp-sockets/server.js

@@ -0,0 +1,10 @@
+'use strict'
+
+const dgram = require('dgram')
+
+const socket = dgram.createSocket('udp4')
+socket.bind(1339)
+
+socket.on('message', (name) => {
+  socket.send(`Hi ${name}!`, 1400)
+})

Chapter03/communicating-over-sockets/unix-sockets/client.js

@@ -0,0 +1,16 @@
+'use strict'
+
+const net = require('net')
+
+const socket = net.connect('/tmp/my.socket')
+const name = process.argv[2] || 'Dave'
+
+socket.write(name)
+
+socket.on('data', (data) => {
+  console.log(data.toString())
+})
+
+socket.on('close', () => {
+  console.log('-> disconnected by server')
+})

Chapter03/communicating-over-sockets/unix-sockets/server.js

@@ -0,0 +1,13 @@
+'use strict'
+
+const net = require('net')
+
+net.createServer((socket) => {
+  console.log('-> client connected')
+  socket.on('data', name => {
+    socket.write(`Hi ${name}!`)
+  })
+  socket.on('close', () => {
+    console.log('-> client disconnected')
+  })
+}).listen('/tmp/my.socket')

Chapter03/fetching-meta-data/checking-file-existence/check.js

@@ -0,0 +1,17 @@
+'use strict'
+
+const fs = require('fs')
+
+const exists = (file) => new Promise((resolve, reject) => {
+  fs.access(file, (err) => {
+    if (err) {
+      if (err.code !== 'ENOENT') { return reject(err) }
+      return resolve({file, exists: false})
+    }
+    resolve({file, exists: true})
+  })  
+})
+
+exists(process.argv[2])
+  .then(({file, exists}) => console.log(`"${file}" does${exists ? '' : ' not'} exist`))
+  .catch(console.error)

Chapter03/fetching-meta-data/getting-symlink-information/meta.js

@@ -0,0 +1,66 @@
+'use strict'
+
+const fs = require('fs')
+const path = require('path')
+const tableaux = require('tableaux')
+
+const write = tableaux(
+  {name: 'Name', size: 20},
+  {name: 'Created', size: 30},
+  {name: 'Inode', size: 10},
+  {name: 'Mode', size: 8},
+  {name: 'Lnks', size: 4},
+  {name: 'Size', size:  6}
+)
+
+function print(dir) {
+  fs.readdirSync(dir)
+    .map((file) => ({file, dir}))
+    .map(toMeta)
+    .forEach(output)
+  write.newline()
+}
+
+function toMeta({file, dir}) {
+  const stats = fs.lstatSync(path.join(dir, file))
+  let {birthtime, ino, mode, nlink, size} = stats
+  birthtime = birthtime.toUTCString()
+  mode = mode.toString(8)
+  size += 'B'
+  return {
+    file,
+    dir,
+    info: [birthtime, ino, mode, nlink, size],
+    isDir: stats.isDirectory(),
+    isSymLink: stats.isSymbolicLink()
+  }
+}
+
+function output({file, dir, info, isDir, isSymLink}) {
+  if (isSymLink) {
+    outputSymlink(file, dir, info)
+    return
+  }
+  write(file, ...info)
+  if (!isDir) { return }
+  const p = path.join(dir, file)
+  write.arrow()
+  fs.readdirSync(p).forEach((f) => {
+    const stats = fs.lstatSync(path.join(p, f))
+    const style = stats.isDirectory() ? 'bold' : 'dim'
+    if (stats.isSymbolicLink()) { f = '\u001b[33m' + f + '\u001b[0m'}
+    write[style](f)
+  })
+  write.newline()
+}
+
+function outputSymlink(file, dir, info) {
+  write('\u001b[33m' + file + '\u001b[0m', ...info)
+  process.stdout.write('\u001b[33m')
+  write.arrow(4)
+  write.bold(fs.readlinkSync(path.join(dir, file)))
+  process.stdout.write('\u001b[0m')
+  write.newline()
+}
+
+print(process.argv[2] || '.')

Chapter03/fetching-meta-data/getting-symlink-information/my-folder/absolute-symlink

@@ -0,0 +1 @@
+/tmp

Chapter03/fetching-meta-data/getting-symlink-information/my-folder/link-to-symlink

@@ -0,0 +1 @@
+my-symlink

Chapter03/fetching-meta-data/getting-symlink-information/my-folder/my-file

@@ -0,0 +1 @@
+my edit

Chapter03/fetching-meta-data/getting-symlink-information/my-folder/my-subdir/subdir-symlink

@@ -0,0 +1 @@
+another-file

Chapter03/fetching-meta-data/getting-symlink-information/my-folder/my-symlink

@@ -0,0 +1 @@
+my-file

Chapter03/fetching-meta-data/getting-symlink-information/my-folder/relative-symlink

@@ -0,0 +1 @@
+../meta.js

Chapter03/fetching-meta-data/getting-symlink-information/my-folder/too-deep

@@ -0,0 +1 @@
+my-subdir/my-subsubdir/too-deep