Autorebuild (#153)

* chokidar rebuild watching + changelog update

tools/watch-file-changes.js

@@ -0,0 +1,83 @@
+// Using chokidar directly, rather than chokidar-cli,
+// because chokidar-cli doesn't work in the slightest,
+// and hasn't been maintained for over three years now.
+
+var chokidar = require('chokidar');
+var runAll = require("npm-run-all");
+var log = console.log.bind(console);
+var rebuildScripts = ["content", "dev:en-GB", "default"];
+
+
+/**
+ * Run an npm script in parallel to whatever
+ * is already running, so that it does not block
+ * anything.
+ */
+function run(scripts, why) {
+  log(`[[CHOKIDAR]] ${why}`);
+
+  runAll(scripts, {
+    stdout: process.stdout,
+    parallel: false
+  })
+  .then(() => {
+      console.log("done!");
+  })
+  .catch(err => {
+      console.log("failed!", err);
+  });
+}
+
+
+function monitor(watcher, scripts) {
+  var ready = false;
+
+  // Add event listeners.
+  watcher
+    .on('add',    path => !ready ? '' : run(scripts, `File ${path} has been added`))
+    .on('change', path => !ready ? '' : run(scripts, `File ${path} has been changed`))
+    .on('unlink', path => !ready ? '' : run(scripts, `File ${path} has been removed`));
+
+  // More possible events.
+  watcher
+    .on('addDir', path => !ready ? '' : run(scripts, `Directory ${path} has been added`))
+    .on('unlinkDir', path => !ready ? '' : run(scripts, `Directory ${path} has been removed`))
+    .on('ready', () => {
+      ready = true;
+      log('Initial scan complete. Ready for changes');
+    })
+//    .on('raw', (event, path, details) => {
+//      log('Raw event info:', event, path, details);
+//    }).
+    .on('error', error => log(`Watcher error: ${error}`));
+}
+
+/**
+ * Watch for code changes
+ */
+monitor(
+  chokidar.watch([
+    'components/**/*.js',
+    'components/**/*.md',
+    'components/**/*.jsx',
+    'lib/**/*.js',
+    'changelog.js'
+  ], {
+    ignored: [
+      'components/sections/**/index.js',
+      'lib/site/handlers.js'
+    ]
+  }),
+  rebuildScripts
+);
+
+/**
+ * Watch for style changes
+ */
+monitor(
+  chokidar.watch(
+    'stylesheets/*.less'
+  ), [
+    "less"
+  ]
+);