From 6d679f8f20757db3cedc6490709e15734961ac9f Mon Sep 17 00:00:00 2001
From: holybiber <samuel@holydevelopers.net>
Date: Fri, 20 Oct 2023 10:51:01 +0200
Subject: [PATCH] Don't throw when files/ directory is missing

Closes #123 where downloading some languages didn't work (because they
had only few worksheets that didn't have images, so there was no files/
directory)
---
 lib/data/globals.dart    |  3 ++-
 lib/data/languages.dart  | 16 +++++++++-------
 test/languages_test.dart | 25 +++++++++++++++++++++++++
 3 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/lib/data/globals.dart b/lib/data/globals.dart
index 5993c4f..6a46a28 100644
--- a/lib/data/globals.dart
+++ b/lib/data/globals.dart
@@ -72,7 +72,8 @@ class Globals {
 
   /// File system path (relative to assets directory)
   /// of the resources in a language
-  /// Must be the main folder name that is inside the zip file we download
+  /// Must be the main folder name that is inside the zip file we download,
+  /// e.g. 'html-en-main'
   static String getLocalPath(String languageCode) {
     return '$htmlPath-$languageCode-$branch';
   }
diff --git a/lib/data/languages.dart b/lib/data/languages.dart
index 5823221..1f5d408 100644
--- a/lib/data/languages.dart
+++ b/lib/data/languages.dart
@@ -145,13 +145,15 @@ class LanguageController extends FamilyNotifier<Language, String> {
       await _checkConsistency(dir, pages);
 
       // Register available images
-      await for (var file in fileSystem
-          .directory(join(path, 'files'))
-          .list(recursive: false, followLinks: false)) {
-        if (file is File) {
-          images[basename(file.path)] = Image(basename(file.path));
-        } else {
-          debugPrint("Found unexpected element $file in files/ directory");
+      var filesDir = fileSystem.directory(join(path, 'files'));
+      if (await filesDir.exists()) {
+        await for (var file
+            in filesDir.list(recursive: false, followLinks: false)) {
+          if (file is File) {
+            images[basename(file.path)] = Image(basename(file.path));
+          } else {
+            debugPrint("Found unexpected element $file in files/ directory");
+          }
         }
       }
       state = Language(
diff --git a/test/languages_test.dart b/test/languages_test.dart
index a02f8a3..a26f2e2 100644
--- a/test/languages_test.dart
+++ b/test/languages_test.dart
@@ -134,6 +134,31 @@ void main() {
         }
         expect(deTest.state.downloaded, false);
       });
+
+      test('A missing files/ dir should be no problem', () async {
+        // We construct a file system in memory with structure/contents.json
+        // filled correctly but where HTML files and the files/ dir are missing
+        var fileSystem = MemoryFileSystem();
+        await fileSystem
+            .directory('assets-de/html-de-main/structure')
+            .create(recursive: true);
+        var readFileSystem = ChrootFileSystem(
+            const LocalFileSystem(), path.canonicalize('test/'));
+        String jsonPath = 'assets-de/html-de-main/structure/contents.json';
+        var contentsJson = fileSystem.file(jsonPath);
+        contentsJson
+            .writeAsString(await readFileSystem.file(jsonPath).readAsString());
+        final container = ProviderContainer(overrides: [
+          languageProvider
+              .overrideWith(() => LanguageController(assetsController: mock)),
+          fileSystemProvider.overrideWith((ref) => fileSystem),
+        ]);
+
+        // init() should work (even if expected HTML files are missing)
+        final deTest = container.read(languageProvider('de').notifier);
+        await deTest.init();
+        expect(deTest.state.downloaded, true);
+      });
     });
 
     test('Test everything with real content from test/assets-de/', () async {