From 2791529dfc897ed00973f6586fdc0f0ef922368b Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Sun, 10 Dec 2023 17:39:38 +0800
Subject: [PATCH 01/15] =?UTF-8?q?=E2=9C=A8=20Introduce=20`CalloutBlockSynt?=
 =?UTF-8?q?ax`?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/markdown.dart                             |  1 +
 .../block_syntaxes/callout_block_syntax.dart  | 89 +++++++++++++++++++
 lib/src/extension_set.dart                    |  2 +
 lib/src/patterns.dart                         |  8 ++
 test/extensions/callout_extension.unit        |  7 ++
 test/markdown_test.dart                       |  4 +
 6 files changed, 111 insertions(+)
 create mode 100644 lib/src/block_syntaxes/callout_block_syntax.dart
 create mode 100644 test/extensions/callout_extension.unit

diff --git a/lib/markdown.dart b/lib/markdown.dart
index 409baaf6..dde88bf0 100644
--- a/lib/markdown.dart
+++ b/lib/markdown.dart
@@ -44,6 +44,7 @@ export 'src/ast.dart';
 export 'src/block_parser.dart';
 export 'src/block_syntaxes/block_syntax.dart';
 export 'src/block_syntaxes/blockquote_syntax.dart';
+export 'src/block_syntaxes/callout_block_syntax.dart';
 export 'src/block_syntaxes/code_block_syntax.dart';
 export 'src/block_syntaxes/dummy_block_syntax.dart';
 export 'src/block_syntaxes/empty_block_syntax.dart';
diff --git a/lib/src/block_syntaxes/callout_block_syntax.dart b/lib/src/block_syntaxes/callout_block_syntax.dart
new file mode 100644
index 00000000..f9587ed9
--- /dev/null
+++ b/lib/src/block_syntaxes/callout_block_syntax.dart
@@ -0,0 +1,89 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import '../ast.dart';
+import '../block_parser.dart';
+import '../line.dart';
+import '../patterns.dart';
+import 'block_syntax.dart';
+import 'code_block_syntax.dart';
+import 'paragraph_syntax.dart';
+
+/// Parses callout blocks.
+/// https://github.com/orgs/community/discussions/16925
+class CalloutBlockSyntax extends BlockSyntax {
+  const CalloutBlockSyntax();
+
+  static final _contentLineRegExp = RegExp(r'>?\s?(.*)*');
+
+  @override
+  RegExp get pattern => calloutPattern;
+
+  /// Whether this callout ends with a lazy continuation line.
+  // The definition of lazy continuation lines:
+  // https://spec.commonmark.org/0.30/#lazy-continuation-line
+  static var _lazyContinuation = false;
+
+  @override
+  List<Line> parseChildLines(BlockParser parser) {
+    // Grab all of the lines that form the callout, stripping off the ">".
+    final childLines = <Line>[];
+    _lazyContinuation = false;
+
+    while (!parser.isDone) {
+      final strippedContent =
+          parser.current.content.replaceFirst(RegExp(r'^\s*>?\s*'), '');
+      final match = _contentLineRegExp.firstMatch(strippedContent);
+      if (match != null) {
+        childLines.add(Line(strippedContent));
+        parser.advance();
+        _lazyContinuation = false;
+        continue;
+      }
+
+      final lastLine = childLines.last;
+
+      // A paragraph continuation is OK. This is content that cannot be parsed
+      // as any other syntax except Paragraph, and it doesn't match the bar in
+      // a Setext header.
+      // Because indented code blocks cannot interrupt paragraphs, a line
+      // matched CodeBlockSyntax is also paragraph continuation text.
+      final otherMatched =
+          parser.blockSyntaxes.firstWhere((s) => s.canParse(parser));
+      if ((otherMatched is ParagraphSyntax &&
+              !lastLine.isBlankLine &&
+              !codeFencePattern.hasMatch(lastLine.content)) ||
+          (otherMatched is CodeBlockSyntax &&
+              !indentPattern.hasMatch(lastLine.content))) {
+        childLines.add(parser.current);
+        _lazyContinuation = true;
+        parser.advance();
+      } else {
+        break;
+      }
+    }
+
+    return childLines;
+  }
+
+  @override
+  Node parse(BlockParser parser) {
+    final type = pattern.firstMatch(parser.current.content)!.group(1)!;
+    parser.advance();
+    final childLines = parseChildLines(parser);
+    // Recursively parse the contents of the callout.
+    final children = BlockParser(childLines, parser.document).parseLines(
+      // The setext heading underline cannot be a lazy continuation line in a
+      // block quote.
+      // https://spec.commonmark.org/0.30/#example-93
+      disabledSetextHeading: _lazyContinuation,
+      parentSyntax: this,
+    );
+
+    return Element('div', [
+      Element('strong', [Text(type)]),
+      ...children,
+    ]);
+  }
+}
diff --git a/lib/src/extension_set.dart b/lib/src/extension_set.dart
index 660759ea..b437647e 100644
--- a/lib/src/extension_set.dart
+++ b/lib/src/extension_set.dart
@@ -1,4 +1,5 @@
 import 'block_syntaxes/block_syntax.dart';
+import 'block_syntaxes/callout_block_syntax.dart';
 import 'block_syntaxes/fenced_code_block_syntax.dart';
 import 'block_syntaxes/footnote_def_syntax.dart';
 import 'block_syntaxes/header_with_id_syntax.dart';
@@ -60,6 +61,7 @@ class ExtensionSet {
         const UnorderedListWithCheckboxSyntax(),
         const OrderedListWithCheckboxSyntax(),
         const FootnoteDefSyntax(),
+        const CalloutBlockSyntax(),
       ],
     ),
     List<InlineSyntax>.unmodifiable(
diff --git a/lib/src/patterns.dart b/lib/src/patterns.dart
index c75838ff..e83a3d9c 100644
--- a/lib/src/patterns.dart
+++ b/lib/src/patterns.dart
@@ -151,3 +151,11 @@ final htmlCharactersPattern = RegExp(
 
 /// A line starts with `[`.
 final linkReferenceDefinitionPattern = RegExp(r'^[ ]{0,3}\[');
+
+/// Callout type patterns.
+/// A callout block starts with [!TYPE], and only 5 types are supported.
+/// The block should ends with a blank line.
+final calloutPattern = RegExp(
+  r'^> \[!(NOTE|TIP|IMPORTANT|CAUTION|WARNING)\]$',
+  multiLine: true,
+);
diff --git a/test/extensions/callout_extension.unit b/test/extensions/callout_extension.unit
new file mode 100644
index 00000000..4db25f81
--- /dev/null
+++ b/test/extensions/callout_extension.unit
@@ -0,0 +1,7 @@
+>>> callout note
+> [!NOTE]
+> Test note callout.
+<<<
+<div><strong>NOTE</strong>
+<p>Test note callout.</p>
+</div>
\ No newline at end of file
diff --git a/test/markdown_test.dart b/test/markdown_test.dart
index 4d21fe89..3c34b4d3 100644
--- a/test/markdown_test.dart
+++ b/test/markdown_test.dart
@@ -42,6 +42,10 @@ void main() async {
     'extensions/unordered_list_with_checkboxes.unit',
     blockSyntaxes: [const UnorderedListWithCheckboxSyntax()],
   );
+  testFile(
+    'extensions/callout_extension.unit',
+    blockSyntaxes: [const CalloutBlockSyntax()],
+  );
   testFile(
     'extensions/autolink_extension.unit',
     inlineSyntaxes: [AutolinkExtensionSyntax()],

From 085eabc6de850bc76f7969787640cb5b01385f8f Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Mon, 11 Dec 2023 10:10:16 +0800
Subject: [PATCH 02/15] =?UTF-8?q?=E2=9A=A1=EF=B8=8F=20More=20flex=20patter?=
 =?UTF-8?q?ns?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/src/patterns.dart | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/src/patterns.dart b/lib/src/patterns.dart
index e83a3d9c..76efbaf1 100644
--- a/lib/src/patterns.dart
+++ b/lib/src/patterns.dart
@@ -153,9 +153,8 @@ final htmlCharactersPattern = RegExp(
 final linkReferenceDefinitionPattern = RegExp(r'^[ ]{0,3}\[');
 
 /// Callout type patterns.
-/// A callout block starts with [!TYPE], and only 5 types are supported.
-/// The block should ends with a blank line.
+/// A callout block is similar to a blockquote,
+/// starts with `> [!TYPE]`, and only 5 types are supported.
 final calloutPattern = RegExp(
-  r'^> \[!(NOTE|TIP|IMPORTANT|CAUTION|WARNING)\]$',
-  multiLine: true,
+  r'^\s{0,3}>\s{0,3}\[!(NOTE|TIP|IMPORTANT|CAUTION|WARNING)\]\s*$',
 );

From cd63f438fb950448d3d67f5a7557bfc8dadb8593 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Mon, 11 Dec 2023 10:40:45 +0800
Subject: [PATCH 03/15] =?UTF-8?q?=F0=9F=9A=80=20Produce=20correct=20struct?=
 =?UTF-8?q?ure?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../block_syntaxes/callout_block_syntax.dart  | 23 ++++++++++++++-----
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/lib/src/block_syntaxes/callout_block_syntax.dart b/lib/src/block_syntaxes/callout_block_syntax.dart
index f9587ed9..74dae897 100644
--- a/lib/src/block_syntaxes/callout_block_syntax.dart
+++ b/lib/src/block_syntaxes/callout_block_syntax.dart
@@ -10,7 +10,7 @@ import 'block_syntax.dart';
 import 'code_block_syntax.dart';
 import 'paragraph_syntax.dart';
 
-/// Parses callout blocks.
+/// Parses GitHub callout blocks.
 /// https://github.com/orgs/community/discussions/16925
 class CalloutBlockSyntax extends BlockSyntax {
   const CalloutBlockSyntax();
@@ -69,7 +69,9 @@ class CalloutBlockSyntax extends BlockSyntax {
 
   @override
   Node parse(BlockParser parser) {
-    final type = pattern.firstMatch(parser.current.content)!.group(1)!;
+    // Parse the callout type from the first line.
+    final type =
+        pattern.firstMatch(parser.current.content)!.group(1)!.toLowerCase();
     parser.advance();
     final childLines = parseChildLines(parser);
     // Recursively parse the contents of the callout.
@@ -81,9 +83,18 @@ class CalloutBlockSyntax extends BlockSyntax {
       parentSyntax: this,
     );
 
-    return Element('div', [
-      Element('strong', [Text(type)]),
-      ...children,
-    ]);
+    // Mapping the callout title text.
+    final titleText = {
+      'note': 'Note',
+      'tip': 'Tip',
+      'important': 'Important',
+      'caution': 'Caution',
+      'warning': 'Warning',
+    }[type]!;
+    final titleElement = Element('p', [Text(titleText)])
+      ..attributes['class'] = 'markdown-alert-title';
+    final elementClass = 'markdown-alert markdown-alert-${type.toLowerCase()}';
+    return Element('div', [titleElement, ...children])
+      ..attributes['class'] = elementClass;
   }
 }

From d0bef01999ae6a7cf1669308316fff23879052a6 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Mon, 11 Dec 2023 10:41:02 +0800
Subject: [PATCH 04/15] =?UTF-8?q?=E2=9A=A1=EF=B8=8F=20Case-insensitive=20t?=
 =?UTF-8?q?ypes?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/src/patterns.dart | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/src/patterns.dart b/lib/src/patterns.dart
index 76efbaf1..1b677c1e 100644
--- a/lib/src/patterns.dart
+++ b/lib/src/patterns.dart
@@ -156,5 +156,6 @@ final linkReferenceDefinitionPattern = RegExp(r'^[ ]{0,3}\[');
 /// A callout block is similar to a blockquote,
 /// starts with `> [!TYPE]`, and only 5 types are supported.
 final calloutPattern = RegExp(
-  r'^\s{0,3}>\s{0,3}\[!(NOTE|TIP|IMPORTANT|CAUTION|WARNING)\]\s*$',
+  r'^\s{0,3}>\s{0,3}\[!(note|tip|important|caution|warning)\]\s*$',
+  caseSensitive: false,
 );

From 3fa039fb6b5147c85a260009d1c6039536ded9db Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Mon, 11 Dec 2023 11:13:21 +0800
Subject: [PATCH 05/15] =?UTF-8?q?=E2=9A=A1=EF=B8=8F=20Improve=20`canParse`?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/src/block_syntaxes/callout_block_syntax.dart | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/src/block_syntaxes/callout_block_syntax.dart b/lib/src/block_syntaxes/callout_block_syntax.dart
index 74dae897..caa90e99 100644
--- a/lib/src/block_syntaxes/callout_block_syntax.dart
+++ b/lib/src/block_syntaxes/callout_block_syntax.dart
@@ -15,15 +15,20 @@ import 'paragraph_syntax.dart';
 class CalloutBlockSyntax extends BlockSyntax {
   const CalloutBlockSyntax();
 
-  static final _contentLineRegExp = RegExp(r'>?\s?(.*)*');
-
   @override
   RegExp get pattern => calloutPattern;
 
+  @override
+  bool canParse(BlockParser parser) {
+    return pattern.hasMatch(parser.current.content) &&
+        parser.lines.any((line) => _contentLineRegExp.hasMatch(line.content));
+  }
+
   /// Whether this callout ends with a lazy continuation line.
   // The definition of lazy continuation lines:
   // https://spec.commonmark.org/0.30/#lazy-continuation-line
-  static var _lazyContinuation = false;
+  static bool _lazyContinuation = false;
+  static final _contentLineRegExp = RegExp(r'>?\s?(.*)*');
 
   @override
   List<Line> parseChildLines(BlockParser parser) {

From 4e18f5313c8938ba5f0a55bf1e0358a863b38295 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Mon, 11 Dec 2023 11:51:16 +0800
Subject: [PATCH 06/15] =?UTF-8?q?=E2=9C=85=20Fill=20test=20cases?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 test/extensions/callout_extension.unit | 87 ++++++++++++++++++++++++--
 1 file changed, 83 insertions(+), 4 deletions(-)

diff --git a/test/extensions/callout_extension.unit b/test/extensions/callout_extension.unit
index 4db25f81..7e7a9c3a 100644
--- a/test/extensions/callout_extension.unit
+++ b/test/extensions/callout_extension.unit
@@ -1,7 +1,86 @@
->>> callout note
-> [!NOTE]
+>>> type note
+> [!NoTe]
 > Test note callout.
 <<<
-<div><strong>NOTE</strong>
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title">Note</p>
 <p>Test note callout.</p>
-</div>
\ No newline at end of file
+</div>
+>>> type tip
+> [!TiP]
+> Test tip callout.
+<<<
+<div class="markdown-alert markdown-alert-tip">
+<p class="markdown-alert-title">Tip</p>
+<p>Test tip callout.</p>
+</div>
+>>> type important
+> [!ImpoRtanT]
+> Test important callout.
+<<<
+<div class="markdown-alert markdown-alert-important">
+<p class="markdown-alert-title">Important</p>
+<p>Test important callout.</p>
+</div>
+>>> type warning
+> [!WarNinG]
+> Test warning callout.
+<<<
+<div class="markdown-alert markdown-alert-warning">
+<p class="markdown-alert-title">Warning</p>
+<p>Test warning callout.</p>
+</div>
+>>> type caution
+> [!CauTioN]
+> Test caution callout.
+<<<
+<div class="markdown-alert markdown-alert-caution">
+<p class="markdown-alert-title">Caution</p>
+<p>Test caution callout.</p>
+</div>
+>>> invalid type
+> [!foo]
+> Test foo callout.
+<<<
+<blockquote>
+<p>[!foo]
+Test foo callout.</p>
+</blockquote>
+>>> contents can both contain/not contain starting quote
+> [!NOTE]
+Test note callout.
+>Test note callout x2.
+<<<
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title">Note</p>
+<p>Test note callout.
+Test note callout x2.</p>
+</div>
+>>> spaces everywhere
+ >  [!NOTE]
+>   Test note callout.
+  > Test note callout x2.
+<<<
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title">Note</p>
+<p>Test note callout.
+Test note callout x2.</p>
+</div>
+>>> title has 3 more spaces then fallback to blockquote
+>    [!NOTE]
+>   Test blockquote.
+<<<
+<blockquote>
+<p>[!NOTE]
+Test blockquote.</p>
+</blockquote>
+>>>nested blockquote
+> [!NOTE]
+>> Test nested blockquote.
+<<<
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title">Note</p>
+<blockquote>
+<p>Test nested blockquote.</p>
+</blockquote>
+</div>

From 4e5f95d658dabe26255cc3b4c43c87282b68d51f Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Mon, 11 Dec 2023 14:55:50 +0800
Subject: [PATCH 07/15] Update AUTHORS

---
 AUTHORS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/AUTHORS b/AUTHORS
index 7f87fc43..ca5b46bf 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -10,4 +10,4 @@ Daniel Schubert <daniel.schubert+github.com@gmail.com>
 Jirka Daněk <dnk@mail.muni.cz>
 Seth Westphal <westy92@gmail.com>
 Tim Maffett <timmaffett@gmail.com>
-
+Alex Li <alexv.525.li@gmail.com>

From abec2dd9b3b3d506fe9a682faecb587487c6ad2f Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Sat, 16 Dec 2023 17:26:29 +0800
Subject: [PATCH 08/15] =?UTF-8?q?=F0=9F=9A=9A=20Rename?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/markdown.dart                             |  2 +-
 ...ck_syntax.dart => alert_block_syntax.dart} | 21 +++++-----
 lib/src/extension_set.dart                    |  4 +-
 lib/src/patterns.dart                         |  9 +++--
 ...ut_extension.unit => alert_extension.unit} | 40 +++++++++----------
 test/markdown_test.dart                       |  7 ++--
 6 files changed, 43 insertions(+), 40 deletions(-)
 rename lib/src/block_syntaxes/{callout_block_syntax.dart => alert_block_syntax.dart} (84%)
 rename test/extensions/{callout_extension.unit => alert_extension.unit} (74%)

diff --git a/lib/markdown.dart b/lib/markdown.dart
index dde88bf0..a09e763a 100644
--- a/lib/markdown.dart
+++ b/lib/markdown.dart
@@ -42,9 +42,9 @@ import 'src/version.dart';
 
 export 'src/ast.dart';
 export 'src/block_parser.dart';
+export 'src/block_syntaxes/alert_block_syntax.dart';
 export 'src/block_syntaxes/block_syntax.dart';
 export 'src/block_syntaxes/blockquote_syntax.dart';
-export 'src/block_syntaxes/callout_block_syntax.dart';
 export 'src/block_syntaxes/code_block_syntax.dart';
 export 'src/block_syntaxes/dummy_block_syntax.dart';
 export 'src/block_syntaxes/empty_block_syntax.dart';
diff --git a/lib/src/block_syntaxes/callout_block_syntax.dart b/lib/src/block_syntaxes/alert_block_syntax.dart
similarity index 84%
rename from lib/src/block_syntaxes/callout_block_syntax.dart
rename to lib/src/block_syntaxes/alert_block_syntax.dart
index caa90e99..cda50968 100644
--- a/lib/src/block_syntaxes/callout_block_syntax.dart
+++ b/lib/src/block_syntaxes/alert_block_syntax.dart
@@ -10,13 +10,14 @@ import 'block_syntax.dart';
 import 'code_block_syntax.dart';
 import 'paragraph_syntax.dart';
 
-/// Parses GitHub callout blocks.
-/// https://github.com/orgs/community/discussions/16925
-class CalloutBlockSyntax extends BlockSyntax {
-  const CalloutBlockSyntax();
+/// Parses GitHub Alerts blocks.
+///
+/// See also: https://docs.github.com/zh/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#alerts
+class AlertBlockSyntax extends BlockSyntax {
+  const AlertBlockSyntax();
 
   @override
-  RegExp get pattern => calloutPattern;
+  RegExp get pattern => alertPattern;
 
   @override
   bool canParse(BlockParser parser) {
@@ -24,7 +25,7 @@ class CalloutBlockSyntax extends BlockSyntax {
         parser.lines.any((line) => _contentLineRegExp.hasMatch(line.content));
   }
 
-  /// Whether this callout ends with a lazy continuation line.
+  /// Whether this alert ends with a lazy continuation line.
   // The definition of lazy continuation lines:
   // https://spec.commonmark.org/0.30/#lazy-continuation-line
   static bool _lazyContinuation = false;
@@ -32,7 +33,7 @@ class CalloutBlockSyntax extends BlockSyntax {
 
   @override
   List<Line> parseChildLines(BlockParser parser) {
-    // Grab all of the lines that form the callout, stripping off the ">".
+    // Grab all of the lines that form the alert, stripping off the ">".
     final childLines = <Line>[];
     _lazyContinuation = false;
 
@@ -74,12 +75,12 @@ class CalloutBlockSyntax extends BlockSyntax {
 
   @override
   Node parse(BlockParser parser) {
-    // Parse the callout type from the first line.
+    // Parse the alert type from the first line.
     final type =
         pattern.firstMatch(parser.current.content)!.group(1)!.toLowerCase();
     parser.advance();
     final childLines = parseChildLines(parser);
-    // Recursively parse the contents of the callout.
+    // Recursively parse the contents of the alert.
     final children = BlockParser(childLines, parser.document).parseLines(
       // The setext heading underline cannot be a lazy continuation line in a
       // block quote.
@@ -88,7 +89,7 @@ class CalloutBlockSyntax extends BlockSyntax {
       parentSyntax: this,
     );
 
-    // Mapping the callout title text.
+    // Mapping the alert title text.
     final titleText = {
       'note': 'Note',
       'tip': 'Tip',
diff --git a/lib/src/extension_set.dart b/lib/src/extension_set.dart
index b437647e..58a25d86 100644
--- a/lib/src/extension_set.dart
+++ b/lib/src/extension_set.dart
@@ -1,5 +1,5 @@
+import 'block_syntaxes/alert_block_syntax.dart';
 import 'block_syntaxes/block_syntax.dart';
-import 'block_syntaxes/callout_block_syntax.dart';
 import 'block_syntaxes/fenced_code_block_syntax.dart';
 import 'block_syntaxes/footnote_def_syntax.dart';
 import 'block_syntaxes/header_with_id_syntax.dart';
@@ -61,7 +61,7 @@ class ExtensionSet {
         const UnorderedListWithCheckboxSyntax(),
         const OrderedListWithCheckboxSyntax(),
         const FootnoteDefSyntax(),
-        const CalloutBlockSyntax(),
+        const AlertBlockSyntax(),
       ],
     ),
     List<InlineSyntax>.unmodifiable(
diff --git a/lib/src/patterns.dart b/lib/src/patterns.dart
index 1b677c1e..81829966 100644
--- a/lib/src/patterns.dart
+++ b/lib/src/patterns.dart
@@ -152,10 +152,11 @@ final htmlCharactersPattern = RegExp(
 /// A line starts with `[`.
 final linkReferenceDefinitionPattern = RegExp(r'^[ ]{0,3}\[');
 
-/// Callout type patterns.
-/// A callout block is similar to a blockquote,
-/// starts with `> [!TYPE]`, and only 5 types are supported.
-final calloutPattern = RegExp(
+/// Alert type patterns.
+/// A alert block is similar to a blockquote,
+/// starts with `> [!TYPE]`, and only 5 types are supported
+/// with case-insensitive.
+final alertPattern = RegExp(
   r'^\s{0,3}>\s{0,3}\[!(note|tip|important|caution|warning)\]\s*$',
   caseSensitive: false,
 );
diff --git a/test/extensions/callout_extension.unit b/test/extensions/alert_extension.unit
similarity index 74%
rename from test/extensions/callout_extension.unit
rename to test/extensions/alert_extension.unit
index 7e7a9c3a..48b74136 100644
--- a/test/extensions/callout_extension.unit
+++ b/test/extensions/alert_extension.unit
@@ -1,70 +1,70 @@
 >>> type note
 > [!NoTe]
-> Test note callout.
+> Test note alert.
 <<<
 <div class="markdown-alert markdown-alert-note">
 <p class="markdown-alert-title">Note</p>
-<p>Test note callout.</p>
+<p>Test note alert.</p>
 </div>
 >>> type tip
 > [!TiP]
-> Test tip callout.
+> Test tip alert.
 <<<
 <div class="markdown-alert markdown-alert-tip">
 <p class="markdown-alert-title">Tip</p>
-<p>Test tip callout.</p>
+<p>Test tip alert.</p>
 </div>
 >>> type important
 > [!ImpoRtanT]
-> Test important callout.
+> Test important alert.
 <<<
 <div class="markdown-alert markdown-alert-important">
 <p class="markdown-alert-title">Important</p>
-<p>Test important callout.</p>
+<p>Test important alert.</p>
 </div>
 >>> type warning
 > [!WarNinG]
-> Test warning callout.
+> Test warning alert.
 <<<
 <div class="markdown-alert markdown-alert-warning">
 <p class="markdown-alert-title">Warning</p>
-<p>Test warning callout.</p>
+<p>Test warning alert.</p>
 </div>
 >>> type caution
 > [!CauTioN]
-> Test caution callout.
+> Test caution alert.
 <<<
 <div class="markdown-alert markdown-alert-caution">
 <p class="markdown-alert-title">Caution</p>
-<p>Test caution callout.</p>
+<p>Test caution alert.</p>
 </div>
 >>> invalid type
 > [!foo]
-> Test foo callout.
+> Test foo alert.
 <<<
 <blockquote>
 <p>[!foo]
-Test foo callout.</p>
+Test foo alert.</p>
 </blockquote>
 >>> contents can both contain/not contain starting quote
 > [!NOTE]
-Test note callout.
->Test note callout x2.
+Test note alert.
+>Test note alert x2.
 <<<
 <div class="markdown-alert markdown-alert-note">
 <p class="markdown-alert-title">Note</p>
-<p>Test note callout.
-Test note callout x2.</p>
+<p>Test note alert.
+Test note alert x2.</p>
 </div>
 >>> spaces everywhere
  >  [!NOTE]
->   Test note callout.
-  > Test note callout x2.
+>   Test note alert.
+  > Test note alert x2.
 <<<
 <div class="markdown-alert markdown-alert-note">
 <p class="markdown-alert-title">Note</p>
-<p>Test note callout.
-Test note callout x2.</p>
+<p>Test note alert.
+Test note alert x2.</p>
 </div>
 >>> title has 3 more spaces then fallback to blockquote
 >    [!NOTE]
diff --git a/test/markdown_test.dart b/test/markdown_test.dart
index 3c34b4d3..1fea6835 100644
--- a/test/markdown_test.dart
+++ b/test/markdown_test.dart
@@ -43,15 +43,16 @@ void main() async {
     blockSyntaxes: [const UnorderedListWithCheckboxSyntax()],
   );
   testFile(
-    'extensions/callout_extension.unit',
-    blockSyntaxes: [const CalloutBlockSyntax()],
+    'extensions/alert_extension.unit',
+    blockSyntaxes: [const AlertBlockSyntax()],
   );
+
+  // Inline syntax extensions
   testFile(
     'extensions/autolink_extension.unit',
     inlineSyntaxes: [AutolinkExtensionSyntax()],
   );
 
-  // Inline syntax extensions
   testFile(
     'extensions/emojis.unit',
     inlineSyntaxes: [EmojiSyntax()],

From bfe95c987d89ab4cee49b67310292a6fc7e31ff5 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Sat, 16 Dec 2023 17:26:45 +0800
Subject: [PATCH 09/15] =?UTF-8?q?=F0=9F=93=9D=20Add=20CHANGELOG?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 CHANGELOG.md | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5fcfd579..97644bab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,8 @@
 
 * Require Dart `^3.1.0`.
 * Update all CommonMark specification links to 0.30.
-* Fix beginning of line detection in `AutolinkExtensionSyntax`. 
+* Fix beginning of line detection in `AutolinkExtensionSyntax`.
+* Add a new syntax `AlertBlockSyntax` to parse GitHub Alerts
 
 ## 7.1.1
 

From 18d05f84706c9fe524cc3125da87657a5282c91b Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Sat, 16 Dec 2023 17:27:25 +0800
Subject: [PATCH 10/15] =?UTF-8?q?=F0=9F=94=A5=20Remove=20`zh`?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/src/block_syntaxes/alert_block_syntax.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/src/block_syntaxes/alert_block_syntax.dart b/lib/src/block_syntaxes/alert_block_syntax.dart
index cda50968..e489b4f2 100644
--- a/lib/src/block_syntaxes/alert_block_syntax.dart
+++ b/lib/src/block_syntaxes/alert_block_syntax.dart
@@ -12,7 +12,7 @@ import 'paragraph_syntax.dart';
 
 /// Parses GitHub Alerts blocks.
 ///
-/// See also: https://docs.github.com/zh/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#alerts
+/// See also: https://docs.github.com/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#alerts
 class AlertBlockSyntax extends BlockSyntax {
   const AlertBlockSyntax();
 

From 18582f7d23c93d98c7cf349c14c79d8cf386bbd2 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Sun, 17 Dec 2023 01:28:38 +0800
Subject: [PATCH 11/15] Update CHANGELOG.md

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 97644bab..fe714142 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 7.1.2-wip
+## 7.2.0-wip
 
 * Require Dart `^3.1.0`.
 * Update all CommonMark specification links to 0.30.

From f3e32983d0c6262466136c84765fa393a19ac143 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Sun, 17 Dec 2023 01:29:04 +0800
Subject: [PATCH 12/15] Update pubspec.yaml

---
 pubspec.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pubspec.yaml b/pubspec.yaml
index 6ddea8fa..2ef835f2 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: markdown
-version: 7.1.2-wip
+version: 7.2.0-wip
 
 description: >-
   A portable Markdown library written in Dart that can parse Markdown into HTML.

From 401ab1c165b7c2c6bd83efd8dc8f453b4b4fed51 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Tue, 19 Dec 2023 09:58:21 +0800
Subject: [PATCH 13/15] =?UTF-8?q?=F0=9F=94=96=20Fix=20version?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/src/version.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/src/version.dart b/lib/src/version.dart
index c8a2b008..a70cac58 100644
--- a/lib/src/version.dart
+++ b/lib/src/version.dart
@@ -1,2 +1,2 @@
 // Generated code. Do not modify.
-const packageVersion = '7.1.2-wip';
+const packageVersion = '7.2.0-wip';

From 6f0a264a8020dfc555123342ad33ebc7b3b7184c Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Tue, 19 Dec 2023 10:02:41 +0800
Subject: [PATCH 14/15] =?UTF-8?q?=F0=9F=A7=AA=20Add=20escape=20brackets=20?=
 =?UTF-8?q?case?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/src/patterns.dart                | 2 +-
 test/extensions/alert_extension.unit | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/src/patterns.dart b/lib/src/patterns.dart
index 81829966..4899ea16 100644
--- a/lib/src/patterns.dart
+++ b/lib/src/patterns.dart
@@ -157,6 +157,6 @@ final linkReferenceDefinitionPattern = RegExp(r'^[ ]{0,3}\[');
 /// starts with `> [!TYPE]`, and only 5 types are supported
 /// with case-insensitive.
 final alertPattern = RegExp(
-  r'^\s{0,3}>\s{0,3}\[!(note|tip|important|caution|warning)\]\s*$',
+  r'^\s{0,3}>\s{0,3}\\?\[!(note|tip|important|caution|warning)\\?\]\s*$',
   caseSensitive: false,
 );
diff --git a/test/extensions/alert_extension.unit b/test/extensions/alert_extension.unit
index 48b74136..c2a3da10 100644
--- a/test/extensions/alert_extension.unit
+++ b/test/extensions/alert_extension.unit
@@ -84,3 +84,11 @@ Test blockquote.</p>
 <p>Test nested blockquote.</p>
 </blockquote>
 </div>
+>>>escape brackets
+> \[!note\]
+> Test escape brackets.
+<<<
+<div class="markdown-alert markdown-alert-note">
+<p class="markdown-alert-title">Note</p>
+<p>Test escape brackets.</p>
+</div>

From c634fcf5dc8a9b0517c902ec129c7b3a5a5cd1c0 Mon Sep 17 00:00:00 2001
From: Alex Li <github@alexv525.com>
Date: Tue, 19 Dec 2023 10:03:41 +0800
Subject: [PATCH 15/15] =?UTF-8?q?=E2=9A=A1=EF=B8=8F=20const=20type=20text?=
 =?UTF-8?q?=20map?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 lib/src/block_syntaxes/alert_block_syntax.dart | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/src/block_syntaxes/alert_block_syntax.dart b/lib/src/block_syntaxes/alert_block_syntax.dart
index e489b4f2..be28ca93 100644
--- a/lib/src/block_syntaxes/alert_block_syntax.dart
+++ b/lib/src/block_syntaxes/alert_block_syntax.dart
@@ -90,13 +90,14 @@ class AlertBlockSyntax extends BlockSyntax {
     );
 
     // Mapping the alert title text.
-    final titleText = {
+    const typeTextMap = {
       'note': 'Note',
       'tip': 'Tip',
       'important': 'Important',
       'caution': 'Caution',
       'warning': 'Warning',
-    }[type]!;
+    };
+    final titleText = typeTextMap[type]!;
     final titleElement = Element('p', [Text(titleText)])
       ..attributes['class'] = 'markdown-alert-title';
     final elementClass = 'markdown-alert markdown-alert-${type.toLowerCase()}';