Give `reskindex.js` a watch mode (-w)

`scripts/reskindex.js -w` will run reskindex in watch mode whereby FS events will cause a reskindex to occur.

This depends on `chokidar`

package.json

@@ -46,6 +46,7 @@
     "blueimp-canvas-to-blob": "^3.5.0",
     "browser-encrypt-attachment": "^0.3.0",
     "browser-request": "^0.3.3",
+    "chokidar": "^1.6.1",
     "classnames": "^2.1.2",
     "commonmark": "^0.27.0",
     "draft-js": "^0.8.1",

scripts/reskindex.js

@@ -1,17 +1,15 @@
 #!/usr/bin/env node
-
 var fs = require('fs');
 var path = require('path');
 var glob = require('glob');
-
 var args = require('optimist').argv;
-
+var chokidar = require('chokidar');
-var header = args.h || args.header;
-
-var componentsDir = path.join('src', 'components');
 
 var componentIndex = path.join('src', 'component-index.js');
+var componentsDir = path.join('src', 'components');
 
+function reskindex() {
+    var header = args.h || args.header;
     var packageJson = JSON.parse(fs.readFileSync('./package.json'));
 
     var strm = fs.createWriteStream(componentIndex);
@@ -26,13 +24,14 @@ strm.write(" * THIS FILE IS AUTO-GENERATED\n");
     strm.write(" * You can edit it you like, but your changes will be overwritten,\n");
     strm.write(" * so you'd just be trying to swim upstream like a salmon.\n");
     strm.write(" * You are not a salmon.\n");
-strm.write(" *\n");
-strm.write(" * To update it, run:\n");
-strm.write(" *    ./reskindex.js -h header\n");
     strm.write(" */\n\n");
 
     if (packageJson['matrix-react-parent']) {
-    strm.write("module.exports.components = require('"+packageJson['matrix-react-parent']+"/lib/component-index').components;\n\n");
+        strm.write(
+            "module.exports.components = require('"+
+            packageJson['matrix-react-parent']+
+            "/lib/component-index').components;\n\n"
+        );
     } else {
         strm.write("module.exports.components = {};\n");
     }
@@ -51,3 +50,18 @@ for (var i = 0; i < files.length; ++i) {
     }
 
     strm.end();
+    console.log('Reskindex: completed');
+}
+
+// -w indicates watch mode where any FS events will trigger reskindex
+if (!args.w) {
+    reskindex();
+    return;
+}
+
+var watchDebouncer = null;
+chokidar.watch('./src').on('all', (event, path) => {
+    if (path === componentIndex) return;
+    if (watchDebouncer) clearTimeout(watchDebouncer);
+    watchDebouncer = setTimeout(reskindex, 1000);
+});