Automatically migrate from old checklist format

This way people existing checklists do not disappear

lib/core/checklist.dart

@@ -47,6 +47,12 @@ class Checklist {
     multiLine: false,
   );
 
+  // FIXME: Added on 2020-05-01: Remove after 3-4 months
+  static final _oldPattern = RegExp(
+    r'^ *\[([ xX])\] +(.*)$',
+    multiLine: false,
+  );
+
   Note _note;
   List<ChecklistItem> items = [];
 
@@ -59,6 +65,11 @@ class Checklist {
 
     for (var i = 0; i < _lines.length; i++) {
       var line = _lines[i];
+      var oldPatMatch = _oldPattern.firstMatch(line);
+      if (oldPatMatch != null) {
+        line = '- ' + line;
+      }
+
       var match = _pattern.firstMatch(line);
       if (match == null) {
         continue;

lib/core/checklist_legacy_migrator.dart

@@ -1,137 +0,0 @@
-import 'package:markdown/markdown.dart' as md;
-
-import 'package:gitjournal/core/note.dart';
-
-class ChecklistLegacyMigrator {
-  Note _note;
-  List<md.Node> nodes;
-
-  ChecklistLegacyMigrator(this._note) {
-    var doc = md.Document(
-      encodeHtml: false,
-      inlineSyntaxes: [TaskListSyntax()],
-      extensionSet: md.ExtensionSet.gitHubFlavored,
-    );
-
-    nodes = doc.parseInline(_note.body);
-    _cleanupNodes(nodes);
-  }
-
-  void _cleanupNodes(List<md.Node> nodes) {
-    if (nodes.length <= 1) {
-      return;
-    }
-
-    var last = nodes.last;
-    var secLast = nodes[nodes.length - 2];
-
-    if (last is! md.Text) {
-      return;
-    }
-    if (secLast is! md.Element) {
-      return;
-    }
-    var elem = secLast as md.Element;
-    if (elem.tag != 'input' || elem.attributes['type'] != 'checkbox') {
-      return;
-    }
-
-    // Some times we get an extra \n in the end, not sure why.
-    if (last.textContent == '\n') {
-      nodes.length = nodes.length - 1;
-      if (!elem.attributes["text"].endsWith('\n')) {
-        elem.attributes["text"] += '\n';
-      }
-    }
-  }
-
-  Note get note {
-    if (nodes.isEmpty) return _note;
-
-    var renderer = CustomRenderer();
-    _note.body = renderer.render(nodes);
-
-    return _note;
-  }
-}
-
-/// Copied from flutter-markdown - cannot be merged as we added xUpperCase and changed the regexp
-/// Parse [task list items](https://github.github.com/gfm/#task-list-items-extension-).
-class TaskListSyntax extends md.InlineSyntax {
-  // FIXME: Waiting for dart-lang/markdown#269 to land
-  static final String _pattern = r'^ *\[([ xX])\] +(.*)';
-
-  TaskListSyntax() : super(_pattern, startCharacter: '['.codeUnitAt(0));
-
-  @override
-  bool onMatch(md.InlineParser parser, Match match) {
-    md.Element el = md.Element.withTag('input');
-    el.attributes['type'] = 'checkbox';
-    el.attributes['checked'] = '${match[1].trim().isNotEmpty}';
-    var m = match[1].trim();
-    if (m.isNotEmpty) {
-      el.attributes['xUpperCase'] = (m[0] == 'X').toString();
-    }
-    el.attributes['text'] = '${match[2]}';
-    parser.addNode(el);
-
-    var lenToConsume = match[0].length;
-    if (match.end + 1 < match.input.length) {
-      lenToConsume += 1; // Consume \n
-    }
-    parser.consume(lenToConsume);
-    return false; // We are advancing manually
-  }
-}
-
-class CustomRenderer implements md.NodeVisitor {
-  StringBuffer buffer;
-
-  @override
-  bool visitElementBefore(md.Element element) {
-    return true;
-  }
-
-  @override
-  void visitText(md.Text text) {
-    //print("visitText ${text.text}#");
-    buffer.write(text.text);
-  }
-
-  @override
-  void visitElementAfter(md.Element element) {
-    final String tag = element.tag;
-
-    if (tag == 'input') {
-      var el = element;
-      if (el is md.Element && el.attributes['type'] == 'checkbox') {
-        bool val = el.attributes['checked'] != 'false';
-        if (val) {
-          if (el.attributes['xUpperCase'] != 'false') {
-            buffer.write('- [x] ');
-          } else {
-            buffer.write('- [X] ');
-          }
-        } else {
-          buffer.write('- [ ] ');
-        }
-        var text = el.attributes['text'];
-        buffer.write(text);
-        //print("writeElem $text#");
-        if (!text.endsWith('\n')) {
-          //print("writeElem newLine#");
-          buffer.write('\n');
-        }
-      }
-    }
-  }
-
-  String render(List<md.Node> nodes) {
-    buffer = StringBuffer();
-
-    for (final node in nodes) {
-      node.accept(this);
-    }
-    return buffer.toString();
-  }
-}

test/checklist_test.dart

@@ -222,5 +222,21 @@ Booga Wooga
       note = checklist.note;
       expect(note.body, content);
     });
+
+    test('Migrate from old checklist format', () async {
+      var content = "[X] One\n[ ] Two";
+
+      var notePath = p.join(tempDir.path, "note448.md");
+      await File(notePath).writeAsString(content);
+
+      var parentFolder = NotesFolderFS(null, tempDir.path);
+      var note = Note(parentFolder, notePath);
+      await note.load();
+
+      var checklist = Checklist(note);
+
+      note = checklist.note;
+      expect(note.body, "- [X] One\n- [ ] Two");
+    });
   });
 }