test: increase coverage for document.dart

lib/src/core/document/document.dart

@@ -2,16 +2,40 @@ import 'dart:collection';
 
 import 'package:appflowy_editor/appflowy_editor.dart';
 
-/// [Document] represents a AppFlowy Editor document structure.
+/// [Document] represents an AppFlowy Editor document structure.
 ///
 /// It stores the root of the document.
 ///
-/// DO NOT directly mutate the properties of a [Document] object.
+/// **DO NOT** directly mutate the properties of a [Document] object.
+///
 class Document {
   Document({
     required this.root,
   });
 
+  /// Constructs a [Document] from a JSON strcuture.
+  ///
+  /// _Example of a [Document] in JSON format:_
+  /// ```
+  /// {
+  ///   'document': {
+  ///     'type': 'page',
+  ///     'children': [
+  ///       {
+  ///         'type': 'paragraph',
+  ///         'data': {
+  ///           'delta': [
+  ///             { 'insert': 'Welcome ' },
+  ///             { 'insert': 'to ' },
+  ///             { 'insert': 'AppFlowy!' }
+  ///           ]
+  ///         }
+  ///       }
+  ///     ]
+  ///   }
+  /// }
+  /// ```
+  ///
   factory Document.fromJson(Map<String, dynamic> json) {
     assert(json['document'] is Map);
 
@@ -32,6 +56,11 @@ class Document {
     );
   }
 
+  /// Creates a blank [Document] containing an empty root [Node].
+  ///
+  /// If [withInitialText] is true, the document will contain an empty
+  /// paragraph [Node].
+  ///
   factory Document.blank({bool withInitialText = false}) {
     final root = Node(
       type: 'page',
@@ -42,12 +71,13 @@ class Document {
     );
   }
 
+  /// The root [Node] of the [Document]
   final Node root;
 
-  /// first node of the document.
+  /// First node of the document.
   Node? get first => root.children.first;
 
-  /// last node of the document.
+  /// Last node of the document.
   Node? get last {
     var last = root.children.last;
     while (last.children.isNotEmpty) {
@@ -133,6 +163,9 @@ class Document {
     return true;
   }
 
+  /// Returns whether the root [Node] does not contain
+  /// any text.
+  ///
   bool get isEmpty {
     if (root.children.isEmpty) {
       return true;
@@ -151,6 +184,8 @@ class Document {
     return false;
   }
 
+  /// Encodes the [Document] into a JSON structure.
+  ///
   Map<String, Object> toJson() {
     return {
       'document': root.toJson(),

test/core/document/document_test.dart

@@ -11,9 +11,16 @@ void main() async {
 
       final node0 = Node(type: '0');
       final node1 = Node(type: '1');
+      final node2 = Node(type: '2');
       expect(document.insert([0], [node0, node1]), true);
       expect(document.nodeAtPath([0])?.type, '0');
       expect(document.nodeAtPath([1])?.type, '1');
+
+      // Insert with an existing node at path
+      expect(document.insert([0], [node2]), true);
+      expect(document.nodeAtPath([0])?.type, '2');
+      expect(document.nodeAtPath([1])?.type, '0');
+      expect(document.nodeAtPath([2])?.type, '1');
     });
 
     test('delete', () {
@@ -32,14 +39,20 @@ void main() async {
     });
 
     test('update', () {
+      final firstRootAttr = {'b': 'c'};
+
       final node = Node(type: 'example', attributes: {'a': 'a'});
-      final document = Document(root: Node(type: 'root'));
+      final document =
+          Document(root: Node(type: 'root', attributes: firstRootAttr));
       document.insert([0], [node]);
 
-      final attributes = {
-        'a': 'b',
-        'b': 'c',
-      };
+      final rootAttributes = {'b': 'b'};
+      final attributes = {'a': 'b', 'b': 'c'};
+
+      // If path is empty, should update attributes of root node
+      expect(document.nodeAtPath([])?.attributes, firstRootAttr);
+      expect(document.update([], rootAttributes), true);
+      expect(document.nodeAtPath([])?.attributes, rootAttributes);
 
       expect(document.update([0], attributes), true);
       expect(document.nodeAtPath([0])?.attributes, attributes);
@@ -140,4 +153,71 @@ void main() async {
       );
     });
   });
+
+  test('first', () {
+    const firstLine = 'Welcome to AppFlowy!';
+
+    final document = Document.fromJson({
+      'document': {
+        'type': 'page',
+        'children': [
+          {
+            'type': 'paragraph',
+            'data': {
+              'delta': [
+                {'insert': firstLine}
+              ],
+            }
+          }
+        ],
+      }
+    });
+
+    final first = document.first;
+
+    expect(first!.delta!.toPlainText(), firstLine);
+  });
+
+  test('last', () {
+    const firstLine = 'Welcome to AppFlowy!';
+    const firstChild = 'Hello';
+    const secondChild = 'World';
+
+    final document = Document.fromJson({
+      'document': {
+        'type': 'page',
+        'children': [
+          {
+            'type': 'paragraph',
+            'data': {
+              'delta': [
+                {'insert': firstLine}
+              ],
+            },
+            'children': [
+              {
+                'type': 'paragraph',
+                'data': {
+                  'delta': [
+                    {'insert': firstChild}
+                  ],
+                },
+              },
+              {
+                'type': 'paragraph',
+                'data': {
+                  'delta': [
+                    {'insert': secondChild}
+                  ],
+                },
+              }
+            ],
+          }
+        ],
+      }
+    });
+
+    final last = document.last!;
+    expect(last.delta!.toPlainText(), secondChild);
+  });
 }