feat(seed): add dasherized titles to unpacked filenames

CONTRIBUTING.md

@@ -499,6 +499,8 @@ When editing the unpacked files, you must only insert or edit lines between comm
 
 Unpacked lines that begin with `//--JSON:` are parsed and inserted verbatim.
 
+If you want to **add a challenge**, **change the order** of challenges in a block, or **edit the title** or any other fields of a challenge, you must do that work *inside the main seed JSON file* and then re-run `unpack`.
+
 ## Challenge Template
 
 ```
@@ -539,9 +541,9 @@ see also
 
 - [Challenge Style Guide](seed/challenge-style-guide.md)
 
-- [Challenge schema](../common/models/challenge.json) - lists all of the fields inside challenge, and describes some of them
+- [Challenge schema](./common/models/challenge.json) - lists all of the fields inside challenge, and describes some of them
 
-- [Challenge types](../common/ap/utils/challengeTypes.js) - what the numeric challenge type values mean (enum) 
+- [Challenge types](./common/ap/utils/challengeTypes.js) - what the numeric challenge type values mean (enum)
 
 
 ### How We Review and Merge Pull Requests
@@ -595,9 +597,9 @@ Be sure to post in the PR conversation that you have made the requested changes.
 
     -   [Contributing to FreeCodeCamp - Writing ES6 Challenge Tests ](https://www.youtube.com/watch?v=iOdD84OSfAE#t=2h49m55s) - a video following [Ethan Arrowood](https://twitter.com/ArrowoodTech) as he contributes to the curriculum
 
-    -   [Challenge schema](../common/models/challenge.json) - lists all of the fields inside challenge, and describes some of them 
+    -   [Challenge schema](./common/models/challenge.json) - lists all of the fields inside challenge, and describes some of them
 
-    -   [Challenge types](../common/ap/utils/challengeTypes.js) - what the numeric challenge type values mean (enum) 
+    -   [Challenge types](./common/ap/utils/challengeTypes.js) - what the numeric challenge type values mean (enum)
 
 * Bugs and Issues:
 

common/utils/index.js

@@ -5,3 +5,6 @@ export function dashify(str) {
     .replace(/[^a-z0-9\-\.]/gi, '')
     .replace(/\:/g, '');
 }
+// todo: unify with server/utils/index.js:dasherize
+const dasherize = dashify;
+export { dasherize };

seed/repack.js

@@ -3,10 +3,8 @@ import fs from 'fs-extra';
 import path from 'path';
 import {UnpackedChallenge, ChallengeFile} from './unpackedChallenge';
 
-const jsdiff = require('diff');
-
 // Repack all challenges from all
-// seed/unpacked/00-foo/bar/000-id.html files
+// seed/unpacked/00-foo/bar/000-xxx-id.html files
 // into
 // seed/challenges/00-foo/bar.json files
 

seed/unpack.js

@@ -15,9 +15,10 @@ import {UnpackedChallenge, ChallengeFile} from './unpackedChallenge';
 // todo: figure out embedded images etc. served from elsewhere in the project
 // todo: prettier/clearer CSS
 
+let unpackedDir = path.join(__dirname, 'unpacked');
+
 // bundle up the test-running JS
 function createUnpackedBundle() {
-  let unpackedDir = path.join(__dirname, 'unpacked');
   fs.mkdirp(unpackedDir, (err) => {
     if (err && err.code !== 'EEXIST') {
       console.log(err);
@@ -44,20 +45,34 @@ function createUnpackedBundle() {
 
 let currentlyUnpackingDir = null;
 
+async function cleanUnpackedDir(unpackedChallengeBlockDir) {
+  let promiseToDelete = function(filePath) {
+    filePath = path.join(unpackedChallengeBlockDir, filePath);
+    return new Promise(() => fs.unlink(filePath));
+  };
+  let promises = fs.readdirSync(unpackedChallengeBlockDir)
+    .filter(filePath => (/\.html$/i).test(filePath))
+    .map(promiseToDelete);
+  await Promise.all(promises);
+}
+
 function unpackChallengeBlock(challengeBlock) {
   let challengeBlockPath = path.parse(challengeBlock.fileName);
   let unpackedChallengeBlockDir = path.join(
-    __dirname,
-    'unpacked',
+    unpackedDir,
     challengeBlockPath.dir,
     challengeBlockPath.name
   );
+
   fs.mkdirp(unpackedChallengeBlockDir, (err) => {
     if (err && err.code !== 'EEXIST') {
       console.log(err);
       throw err;
     }
 
+    // remove existing unpacked files
+    cleanUnpackedDir(unpackedChallengeBlockDir);
+
     if (currentlyUnpackingDir !== challengeBlockPath.dir) {
       currentlyUnpackingDir = challengeBlockPath.dir;
       console.log(`Unpacking into ${currentlyUnpackingDir}:`);

seed/unpackedChallenge.js

@@ -2,6 +2,7 @@
 import fs from 'fs-extra';
 import path from 'path';
 import _ from 'lodash';
+import { dasherize } from '../common/utils';
 
 const jsonLinePrefix = '//--JSON:';
 const paragraphBreak = '<!--break-->';
@@ -28,7 +29,6 @@ class ChallengeFile {
     });
   }
 
-
   readChunks() {
     // todo: make this work async
     // todo: make sure it works with encodings
@@ -142,7 +142,7 @@ class UnpackedChallenge {
     // eslint-disable-next-line no-nested-ternary
     let prefix = ((this.index < 10) ? '00' : (this.index < 100) ? '0' : '')
       + this.index;
-    return `${prefix}-${this.challenge.id}`;
+    return `${prefix}-${dasherize(this.challenge.title)}-${this.challenge.id}`;
   }
 
   expandedDescription() {