[tool] Add check for blank lines in CHANGELOG lists

packages/google_fonts/CHANGELOG.md

@@ -571,7 +571,6 @@
   - `Wix Madefor Display`
   - `Wix Madefor Text`
   - `Ysabeau`
-
 - Removed fonts:
   - `Arima Madurai`
   - `Fredoka One`

packages/google_maps_flutter/google_maps_flutter/CHANGELOG.md

@@ -611,7 +611,6 @@ GoogleMapController is now uniformly driven by implementing `DefaultLifecycleObs
 ## 0.5.19
 
 * Adds support for toggling Indoor View on or off.
-
 * Allow BitmapDescriptor scaling override
 
 ## 0.5.18

packages/google_sign_in/google_sign_in/CHANGELOG.md

@@ -191,7 +191,6 @@ For every platform other than `web`, this version should be identical to `5.4.4`
 ## 5.1.0
 
 * Add reAuthenticate option to signInSilently to allow re-authentication to be requested
-
 * Updated Android lint settings.
 
 ## 5.0.7

packages/image_picker/image_picker/CHANGELOG.md

@@ -129,7 +129,6 @@
 ## 0.8.6+2
 
 * Updates `NSPhotoLibraryUsageDescription` description in README.
-
 * Updates minimum Flutter version to 3.0.
 
 ## 0.8.6+1

packages/video_player/video_player/CHANGELOG.md

@@ -605,14 +605,12 @@ DefaultHttpDataSourceFactory by default.
 ## 0.10.0+8
 
 * iOS: Fix an issue where the player sends initialization message incorrectly.
-
 * Fix a few other IDE warnings.
 
 
 ## 0.10.0+7
 
 * Android: Fix issue where buffering status in percentage instead of milliseconds
-
 * Android: Update buffering status everytime we notify for position change
 
 ## 0.10.0+6

packages/video_player/video_player_android/CHANGELOG.md

@@ -203,7 +203,6 @@
 ## 2.7.2
 
 * Updates minimum supported SDK version to Flutter 3.24/Dart 3.5.
-
 * Re-adds Impeller support.
 
 ## 2.7.1

script/tool/lib/src/version_check_command.dart

@@ -540,6 +540,35 @@ ${indentation}The first version listed in CHANGELOG.md is $fromChangeLog.
       }
     }
 
+    // Check for blank lines between list items in the version section.
+    bool inList = false;
+    bool seenBlankLineInList = false;
+    final RegExp listItemRegex = RegExp(r'^\s*[*+-]\s');
+    while (iterator.moveNext()) {
+      final String line = iterator.current;
+      final bool isListItem = listItemRegex.hasMatch(line);
+      final bool isBlank = line.trim().isEmpty;
+
+      if (isListItem) {
+        if (seenBlankLineInList) {
+          printError(
+              '${indentation}Blank lines found between list items in CHANGELOG.\n'
+              '${indentation}This creates multiple separate lists on pub.dev.\n'
+              '${indentation}Remove blank lines to keep all items in a single list.');
+          return false;
+        }
+        inList = true;
+      } else if (isBlank) {
+        if (inList) {
+          seenBlankLineInList = true;
+        }
+      } else {
+        // Any other non-blank, non-list line resets the state (e.g. new headers, text).
+        inList = false;
+        seenBlankLineInList = false;
+      }
+    }
+
     return true;
   }
 

script/tool/test/version_check_command_test.dart

@@ -487,6 +487,80 @@ void main() {
       );
     });
 
+    test('Fail if CHANGELOG list items have a blank line', () async {
+      const String version = '1.0.1';
+      final RepositoryPackage plugin =
+          createFakePlugin('plugin', packagesDir, version: version);
+
+      // Blank line breaks the list items.
+      const String changelog = '''
+## $version
+
+* First item.
+
+* Second item.
+* Third item.
+''';
+      plugin.changelogFile.writeAsStringSync(changelog);
+      gitProcessRunner.mockProcessesForExecutable['git-show'] =
+          <FakeProcessInfo>[
+        FakeProcessInfo(MockProcess(stdout: 'version: 1.0.0')),
+      ];
+      Error? commandError;
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['version-check', '--base-sha=main'],
+          errorHandler: (Error e) {
+        commandError = e;
+      });
+
+      expect(commandError, isA<ToolExit>());
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('Blank lines found between list items in CHANGELOG.'),
+          contains('CHANGELOG.md failed validation.'),
+        ]),
+      );
+    });
+
+    test('Fail if CHANGELOG list items have a blank line with nested items',
+        () async {
+      const String version = '1.0.1';
+      final RepositoryPackage plugin =
+          createFakePlugin('plugin', packagesDir, version: version);
+
+      // Blank line in nested list items.
+      const String changelog = '''
+## $version
+
+* Top level item.
+  * Nested item A.
+
+  * Nested item B.
+* Another top level item.
+''';
+      plugin.changelogFile.writeAsStringSync(changelog);
+      gitProcessRunner.mockProcessesForExecutable['git-show'] =
+          <FakeProcessInfo>[
+        FakeProcessInfo(MockProcess(stdout: 'version: 1.0.0')),
+      ];
+      Error? commandError;
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['version-check', '--base-sha=main'],
+          errorHandler: (Error e) {
+        commandError = e;
+      });
+
+      expect(commandError, isA<ToolExit>());
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('Blank lines found between list items in CHANGELOG.'),
+          contains('CHANGELOG.md failed validation.'),
+        ]),
+      );
+    });
+
     test(
       'Fail if pubspec version only matches an older version listed in CHANGELOG',
       () async {