Move third party libs to third_party/ (#1981)

* Refactor _addDirectory

* Optional relative dir

* Move third party libs to third_party/

Author: isoos

app/lib/frontend/static_files.dart

@@ -42,15 +42,27 @@ String _resolveStaticDirPath() {
   return path.join(resolveAppDir(), '../static');
 }
 
+String _resolveRootDirPath() =>
+    Directory(path.join(resolveAppDir(), '../')).resolveSymbolicLinksSync();
+Directory _resolveDir(String relativePath) =>
+    Directory(path.join(_resolveRootDirPath(), relativePath)).absolute;
+
 /// Stores static files in memory for fast http serving.
 class StaticFileCache {
   final _files = <String, StaticFile>{};
 
   StaticFileCache();
 
   StaticFileCache.withDefaults() {
-    final staticsDirectory = new Directory(_resolveStaticDirPath()).absolute;
-    staticsDirectory
+    _addDirectory(Directory(_resolveStaticDirPath()).absolute);
+    final thirdPartyDir = _resolveDir('third_party');
+    _addDirectory(_resolveDir('third_party/highlight'), baseDir: thirdPartyDir);
+    _addDirectory(_resolveDir('third_party/css'), baseDir: thirdPartyDir);
+  }
+
+  void _addDirectory(Directory contentDir, {Directory baseDir}) {
+    baseDir ??= contentDir;
+    contentDir
         .listSync(recursive: true)
         .where((fse) => fse is File)
         .map((file) => file.absolute as File)
@@ -59,8 +71,7 @@ class StaticFileCache {
         final contentType = mime.lookupMimeType(file.path) ?? 'octet/binary';
         final bytes = file.readAsBytesSync();
         final lastModified = file.lastModifiedSync();
-        final relativePath =
-            path.relative(file.path, from: staticsDirectory.path);
+        final relativePath = path.relative(file.path, from: baseDir.path);
         final isRoot = _staticRootPaths.contains(relativePath);
         final prefix = isRoot ? '' : _defaultStaticPath;
         final requestPath = '$prefix/$relativePath';

app/test/frontend/static_files_test.dart

@@ -61,4 +61,22 @@ Future main() async {
       }
     });
   });
+
+  group('default content', () {
+    final cache = StaticFileCache.withDefaults();
+    final files = [
+      '/static/css/github-markdown.css',
+      '/static/highlight/github.css',
+      '/static/highlight/highlight.pack.js',
+      '/static/highlight/init.js',
+    ];
+
+    for (String file in files) {
+      test('$file exists', () {
+        final f = cache.getFile(file);
+        expect(f, isNotNull);
+        expect(f.etag.contains('mocked_hash_'), isFalse);
+      });
+    }
+  });
 }