fix: read history commits when body contains multi lines

This commit's body contains multi lines

But passed finally

lib/src/read.dart

@@ -1,6 +1,8 @@
 import 'dart:io';
 import 'package:path/path.dart';
 
+const _kDelimiter = '------------------------ >8 ------------------------';
+
 /// Read commit messages in given range([from], [to]),
 ///  or in [edit] file.
 /// Return commit messages list.
@@ -17,7 +19,7 @@ Future<Iterable<String>> read({
   }
   final range = [if (from != null) from, to ?? 'HEAD'].join('..');
   return _getRangeCommits(
-    gitLogArgs: ['--format=%B', range, ...?gitLogArgs],
+    gitLogArgs: ['--format=%B%n$_kDelimiter', range, ...?gitLogArgs],
     workingDirectory: workingDirectory,
   );
 }
@@ -35,8 +37,8 @@ Future<Iterable<String>> _getRangeCommits({
     throw ProcessException(
         'git', ['log', ...gitLogArgs], result.stderr, result.exitCode);
   }
-  return ((result.stdout as String).trim().split('\n'))
-      .where((message) => message.trim().isNotEmpty)
+  return ((result.stdout as String).split('$_kDelimiter\n'))
+      .where((message) => message.isNotEmpty)
       .toList();
 }
 
@@ -52,7 +54,8 @@ Future<Iterable<String>> _getEditingCommit({
   final root = result.stdout.toString().trim();
   final file = File(join(root, edit));
   if (await file.exists()) {
-    return [await file.readAsString()];
+    final message = await file.readAsString();
+    return ['$message\n'];
   }
   return [];
 }

test/lint_test.dart

@@ -91,4 +91,31 @@ void main() {
         }),
         throwsRangeError);
   });
+
+  test('positive on multi-line body message', () async {
+    final message = '''chore(deps): bump commitlint_cli from 0.5.0 to 0.6.0
+Bumps [commitlint_cli](https://github.com/hyiso/commitlint) from 0.5.0 to 0.6.0.
+- [Release notes](https://github.com/hyiso/commitlint/releases)
+- [Changelog](https://github.com/hyiso/commitlint/blob/main/CHANGELOG.md)
+- [Commits](hyiso/commitlint@v0.5.0...v0.6.0)
+
+---
+updated-dependencies:
+- dependency-name: commitlint_cli
+  dependency-type: direct:production
+  update-type: version-update:semver-minor
+...
+
+Signed-off-by: dependabot[bot] <support@github.com>
+
+''';
+    final result = await lint(message, {
+      'type-empty': Rule(
+        severity: RuleSeverity.error,
+        condition: RuleCondition.never,
+      ),
+    });
+    expect(result.valid, true);
+    expect(result.input, equals(message));
+  });
 }

test/read_test.dart

@@ -10,7 +10,7 @@ void main() {
     final dir = await git.bootstrap();
     await File(join(dir, 'commit-msg-file')).writeAsString('foo');
     final commits = await read(edit: 'commit-msg-file', workingDirectory: dir);
-    expect(commits, equals(['foo']));
+    expect(commits, equals(['foo\n']));
   });
 
   test('get edit commit message from git root', () async {
@@ -19,7 +19,7 @@ void main() {
     await Process.run('git', ['add', '.'], workingDirectory: dir);
     await Process.run('git', ['commit', '-m', 'alpha'], workingDirectory: dir);
     final commits = await read(workingDirectory: dir);
-    expect(commits, equals(['alpha']));
+    expect(commits, equals(['alpha\n\n']));
   });
 
   test('get history commit messages', () async {
@@ -31,7 +31,7 @@ void main() {
     await Process.run('git', ['commit', '-m', 'remove alpha'],
         workingDirectory: dir);
     final commits = await read(workingDirectory: dir);
-    expect(commits, equals(['remove alpha', 'alpha']));
+    expect(commits, equals(['remove alpha\n\n', 'alpha\n\n']));
   });
 
   test('get edit commit message from git subdirectory', () async {
@@ -43,7 +43,7 @@ void main() {
     await Process.run('git', ['commit', '-m', 'beta'], workingDirectory: dir);
 
     final commits = await read(workingDirectory: dir);
-    expect(commits, equals(['beta']));
+    expect(commits, equals(['beta\n\n']));
   });
 
   test('get edit commit message while skipping first commit', () async {
@@ -65,6 +65,35 @@ void main() {
         from: 'HEAD~2',
         workingDirectory: dir,
         gitLogArgs: '--skip 1'.split(' '));
-    expect(commits, equals(['beta']));
+    expect(commits, equals(['beta\n\n']));
+  });
+
+  test('get history commit messages - body contains multi lines', () async {
+    final bodyMultiLineMessage =
+        '''chore(deps): bump commitlint_cli from 0.5.0 to 0.6.0
+Bumps [commitlint_cli](https://github.com/hyiso/commitlint) from 0.5.0 to 0.6.0.
+- [Release notes](https://github.com/hyiso/commitlint/releases)
+- [Changelog](https://github.com/hyiso/commitlint/blob/main/CHANGELOG.md)
+- [Commits](hyiso/commitlint@v0.5.0...v0.6.0)
+
+---
+updated-dependencies:
+- dependency-name: commitlint_cli
+  dependency-type: direct:production
+  update-type: version-update:semver-minor
+...
+
+Signed-off-by: dependabot[bot] <support@github.com>''';
+    final dir = await git.bootstrap();
+    await File(join(dir, 'alpha.txt')).writeAsString('alpha');
+    await Process.run('git', ['add', 'alpha.txt'], workingDirectory: dir);
+    await Process.run('git', ['commit', '-m', 'alpha'], workingDirectory: dir);
+    await File(join(dir, 'beta.txt')).writeAsString('beta');
+    await Process.run('git', ['add', 'beta.txt'], workingDirectory: dir);
+    await Process.run('git', ['commit', '-m', bodyMultiLineMessage],
+        workingDirectory: dir);
+
+    final commits = await read(from: 'HEAD~1', workingDirectory: dir);
+    expect(commits, equals(['$bodyMultiLineMessage\n\n']));
   });
 }