chapter 2: initial samples

Chapter02/communicating-with-sockets/client.js

@@ -0,0 +1,12 @@
+const net = require('net');
+
+const HOSTNAME = 'localhost';
+const PORT = 3000;
+
+const socket = net.connect(PORT, HOSTNAME);
+
+socket.write('World');
+
+socket.on('data', (data) => {
+    console.log(data.toString());
+});

Chapter02/communicating-with-sockets/server.js

@@ -0,0 +1,13 @@
+const net = require('net');
+
+const HOSTNAME = 'localhost';
+const PORT = 3000;
+
+net.createServer((socket) => {
+    console.log('Client connected.');
+
+    socket.on('data', name => {
+        socket.write(`Hello ${name}!`);
+    });
+
+}).listen(PORT, HOSTNAME);

Chapter02/fetching-metadata/chmod-octal.js

@@ -0,0 +1,6 @@
+'use strict'
+
+const fs = require('fs');
+const file = './file.txt';
+
+fs.chmodSync("./file.txt", 0o664);

Chapter02/fetching-metadata/chmod.js

@@ -0,0 +1,9 @@
+'use strict'
+
+const fs = require('fs');
+const file = './file.txt';
+
+fs.chmodSync("./file.txt",
+    fs.constants.S_IRUSR | fs.constants.S_IWUSR |
+    fs.constants.S_IRGRP | fs.constants.S_IWGRP |
+    fs.constants.S_IROTH);

Chapter02/fetching-metadata/metadata.js

@@ -0,0 +1,9 @@
+const fs = require('fs');
+const file = process.argv[2];
+
+function printMetadata(file) {
+    const fileStats = fs.statSync(file);
+    console.log(fileStats);
+};
+
+printMetadata(file);

Chapter02/fetching-metadata/metadata2.js

@@ -0,0 +1,13 @@
+const fs = require('fs');
+const file = process.argv[2];
+
+function printMetadata(file) {
+    try {
+        const fileStats = fs.statSync(file);
+        console.log(fileStats);
+    } catch (err) {
+        console.error("Error reading file path:", file);
+    }
+};
+
+printMetadata(file);

Chapter02/file-watching/file.txt

@@ -0,0 +1,12 @@
+HELLO!
+ ls 
+ Hello again;
+ gs
+ gsgds
+ gsdsdf
+ sddsf
+ sdfsd
+ sdda
+ dfsdf
+ dsad
+ sdasd

Chapter02/file-watching/package-lock.json

@@ -0,0 +1,13 @@
+{
+  "name": "file-watching",
+  "version": "1.0.0",
+  "lockfileVersion": 1,
+  "requires": true,
+  "dependencies": {
+    "moment": {
+      "version": "2.24.0",
+      "resolved": "https://registry.npmjs.org/moment/-/moment-2.24.0.tgz",
+      "integrity": "sha512-bV7f+6l2QigeBBZSM/6yTNq4P2fNpSWj/0e7jQcy87A8e7o2nAfP/34/2ky5Vw4B9S446EtIhodAzkFCcR4dQg=="
+    }
+  }
+}

Chapter02/file-watching/package.json

@@ -0,0 +1,16 @@
+{
+  "name": "file-watching",
+  "version": "1.0.0",
+  "main": "watch.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "moment": "^2.24.0"
+  },
+  "devDependencies": {},
+  "description": ""
+}

Chapter02/file-watching/watch.js

@@ -0,0 +1,6 @@
+const fs = require('fs');
+const file = './file.txt';
+
+fs.watchFile(file, (current, previous) => {
+    return console.log(`${file} updated ${time}`)
+});

Chapter02/file-watching/watch2.js

@@ -0,0 +1,8 @@
+const fs = require('fs');
+const file = './file.txt';
+const moment = require('moment');
+
+fs.watch(file, (eventType, filename) => {
+    const time = moment().format('MMMM Do YYYY, h:mm:ss a');
+    return console.log(`${filename} updated ${time}`)
+});

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

@@ -1,22 +0,0 @@
-{
-  "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

@@ -1,25 +0,0 @@
-{
-  "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

@@ -1,26 +0,0 @@
-{
-  "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/interfacing-with-io/greeting.js

@@ -0,0 +1,4 @@
+process.stdin.on('data', (data) => {
+    let name = data.toString().trim().toUpperCase();
+    process.stdout.write(`Hello ${name}!`);   
+});

Chapter02/interfacing-with-io/greeting2.js

@@ -0,0 +1,8 @@
+process.stdin.on('data', data => {
+    let name = data.toString().trim().toUpperCase();
+    if (name != '') {
+        process.stdout.write(`Hello ${name}!`);
+    } else {
+        process.stderr.write('Input was empty.');
+    }
+});

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

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

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

@@ -1,6 +0,0 @@
-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

@@ -1,66 +0,0 @@
-// 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

@@ -1,33 +0,0 @@
-{
-  "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

@@ -1,50 +0,0 @@
-#! /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

@@ -1,31 +0,0 @@
-# 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

@@ -1,74 +0,0 @@
-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

@@ -1,11 +0,0 @@
-{
-  "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

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

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

@@ -1,6 +0,0 @@
-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

@@ -1,59 +0,0 @@
-// 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

@@ -1,30 +0,0 @@
-{
-  "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

@@ -1,32 +0,0 @@
-# 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

@@ -1,74 +0,0 @@
-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

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

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

@@ -1,6 +0,0 @@
-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

@@ -1,66 +0,0 @@
-// 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

@@ -1,30 +0,0 @@
-{
-  "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

@@ -1,31 +0,0 @@
-# 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

@@ -1,74 +0,0 @@
-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

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

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

@@ -1,6 +0,0 @@
-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

@@ -1,66 +0,0 @@
-// 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

@@ -1,32 +0,0 @@
-{
-  "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

@@ -1,31 +0,0 @@
-# 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

@@ -1,74 +0,0 @@
-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

@@ -1,19 +0,0 @@
-{
-  "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

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

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

@@ -1,19 +0,0 @@
-{
-  "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

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

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

@@ -1,6 +0,0 @@
-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

@@ -1,66 +0,0 @@
-// 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

@@ -1,33 +0,0 @@
-{
-  "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

@@ -1,50 +0,0 @@
-#! /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

@@ -1,31 +0,0 @@
-# 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

@@ -1,74 +0,0 @@
-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/working-with-files/callback-hell.js

@@ -0,0 +1,5 @@
+first(args, function () {
+    second(args, function () {
+        third(args, function () {})
+    })
+})

Chapter02/working-with-files/hello.txt

@@ -0,0 +1 @@
+HELLO WORLD!

Chapter02/working-with-files/readWriteAsync.js

@@ -0,0 +1,16 @@
+const fs = require('fs');
+const path = require('path')
+
+const filepath = path.join(process.cwd(), 'hello.txt');
+
+fs.readFile(filepath, 'utf8', function (err, contents) {
+    if (err) {
+        return console.log(err);
+    }
+    console.log("File Contents:", contents);
+    contents = contents.toUpperCase();
+    fs.writeFile(filepath, contents, function (err) {
+        if (err) throw err;
+        console.log("File updated.")
+    });
+});

Chapter02/working-with-files/readWriteAsync2.js

@@ -0,0 +1,20 @@
+const fs = require('fs');
+const path = require('path')
+
+const filepath = path.join(process.cwd(), 'hello.txt');
+
+fs.readFile(filepath, 'utf8', function (err, contents) {
+    if (err) {
+        return console.log(err);
+    }
+    console.log("File Contents:", contents);
+    contents = contents.toUpperCase();
+    updateFile(filepath, contents);
+});
+
+function updateFile(filepath, contents) {
+    fs.writeFile(filepath, contents, function (err) {
+        if (err) throw err;
+        console.log("File updated.");
+    });
+};

Chapter02/working-with-files/readWritePromise.js

@@ -0,0 +1,15 @@
+const fs = require("fs").promises;
+const path = require('path');
+
+const filepath = path.join(process.cwd(), 'hello.txt');
+
+async function run() {
+    try {
+        const contents = await fs.readFile(filepath, 'utf8');
+        console.log("File Contents:", contents);
+    } catch (error) {
+        console.error(error);
+    }
+};
+
+run();

Chapter02/working-with-files/readWriteSync.js

@@ -0,0 +1,12 @@
+const fs = require('fs');
+const path = require('path');
+
+const filepath = path.join(process.cwd(), 'hello.txt');
+
+let contents = fs.readFileSync(filepath, 'utf8');
+console.log("File Contents:", contents);
+
+contents = contents.toString().toUpperCase();
+
+fs.writeFileSync(filepath, contents);
+console.log("File updated.");

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

@@ -1,59 +0,0 @@
-// 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

@@ -1,27 +0,0 @@
-{
-  "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

@@ -1,74 +0,0 @@
-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

@@ -1,59 +0,0 @@
-// 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

@@ -1,26 +0,0 @@
-{
-  "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

@@ -1,59 +0,0 @@
-// 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

@@ -1,27 +0,0 @@
-{
-  "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

@@ -1,90 +0,0 @@
-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()
-})