Only copy changed files when watching

Author: moonglum

lib/build-bundler.js

@@ -7,9 +7,17 @@ let readFile = promisify(fs.readFile);
 let readdir = promisify(fs.readdir);
 
 module.exports = ({ source, target, fingerprint, configDir }) => {
-	// TODO: Only copy changed files
-	return _ => {
-		return readdir(source).then(sources => {
+	return files => {
+		let filesToCopy;
+
+		if(files) {
+			filesToCopy = filesWithinDirectory(source, files);
+		} else {
+			// TODO: Get that entire tree
+			filesToCopy = readdir(source);
+		}
+
+		return filesToCopy.then(sources => {
 			return Promise.all(sources.map(fileName => {
 				let sourcePath = path.join(source, fileName);
 
@@ -32,3 +40,11 @@ module.exports = ({ source, target, fingerprint, configDir }) => {
 		});
 	};
 };
+
+function filesWithinDirectory(directory, files) {
+	return new Promise(resolve => {
+		resolve(files.
+			map(file => path.relative(directory, file)).
+			filter(file => !file.startsWith("..")));
+	});
+}