feat(seed): "unpack" and "repack" scripts

add "npm run seed" as alias to "node seed"

unpack tests and solution into HTML file; add titles and help text; style unpacked file

enable running unpacked assert tests in browser

Using browserify, compile "tape", "lodash", jQuery into "unpacked-bundle.js" for use during in-browser unpacked tests

feat(seed): diff after repacking

feat(seed): unpacked tests use Browser TAP chrome dev tool if available

unpack.js

@@ -0,0 +1,87 @@
+/* eslint-disable no-eval, no-process-exit */
+import fs from 'fs-extra';
+import path from 'path';
+import browserify from 'browserify';
+import getChallenges from './getChallenges';
+import {UnpackedChallenge, ChallengeFile} from './unpackedChallenge';
+
+// Unpack all challenges
+// from all seed/challenges/00-foo/bar.json files
+// into seed/unpacked/00-foo/bar/000-id.html files
+//
+// todo: unpack translations too
+// todo: use common/app/routes/Challenges/utils/index.js:15 maps
+// to determine format/style for non-JS tests
+// todo: figure out embedded images etc. served from elsewhere in the project
+// todo: prettier/clearer CSS
+
+// bundle up the test-running JS
+function createUnpackedBundle() {
+  let unpackedFile = path.join(__dirname, 'unpacked.js');
+  let b = browserify(unpackedFile).bundle();
+  b.on('error', console.error);
+  let unpackedBundleFile =
+    path.join(__dirname, 'unpacked', 'unpacked-bundle.js');
+  const bundleFileStream = fs.createWriteStream(unpackedBundleFile);
+  bundleFileStream.on('finish', () => {
+    console.log('Wrote bundled JS into ' + unpackedBundleFile);
+  });
+  bundleFileStream.on('pipe', () => {
+    console.log('Writing bundled JS...');
+  });
+  bundleFileStream.on('error', console.error);
+  b.pipe(bundleFileStream);
+  // bundleFileStream.end();  // do not do this prematurely!
+}
+
+let currentlyUnpackingDir = null;
+
+function unpackChallengeBlock(challengeBlock) {
+  let challengeBlockPath = path.parse(challengeBlock.fileName);
+  let unpackedChallengeBlockDir = path.join(
+    __dirname,
+    'unpacked',
+    challengeBlockPath.dir,
+    challengeBlockPath.name
+  );
+  fs.mkdirp(unpackedChallengeBlockDir, (err) => {
+    if (err && err.code !== 'EEXIST') {
+      console.log(err);
+      throw err;
+    }
+
+    if (currentlyUnpackingDir !== challengeBlockPath.dir) {
+      currentlyUnpackingDir = challengeBlockPath.dir;
+      console.log(`Unpacking into ${currentlyUnpackingDir}:`);
+    }
+    console.log(`  ${challengeBlock.name}`);
+
+    // write a copy of the challenge block into unpacked dir
+    delete challengeBlock.fileName;
+    delete challengeBlock.superBlock;
+    delete challengeBlock.superOrder;
+    let challengeBlockCopy =
+      new ChallengeFile(
+        unpackedChallengeBlockDir,
+        challengeBlockPath.name,
+        '.json');
+    challengeBlockCopy.write(JSON.stringify(challengeBlock, null, 2));
+
+    // unpack each challenge into an HTML file
+    let index = 0;
+    challengeBlock.challenges.forEach(challenge => {
+      new UnpackedChallenge(
+        unpackedChallengeBlockDir,
+        challenge,
+        index
+      ).unpack();
+      index += 1;
+    });
+  });
+}
+
+createUnpackedBundle();
+let challenges = getChallenges();
+challenges.forEach(challengeBlock => {
+  unpackChallengeBlock(challengeBlock);
+});