Add support for MyST nested directives

sybil/parsers/myst/lexers.py

@@ -3,14 +3,14 @@
 
 from sybil import Document, Region
 from sybil.parsers.abstract.lexers import BlockLexer
-from sybil.parsers.markdown.lexers import CODEBLOCK_END_TEMPLATE
 from sybil.parsers.rest.lexers import parse_options_and_source
 
 DIRECTIVE_START_TEMPLATE = (
-    r"^(?P<prefix>[ \t]*)```\{{(?P<directive>{directive})}} ?(?P<arguments>{arguments})$\n"
+    r"^(?P<prefix>[ \t]*)```+\{{(?P<directive>{directive})}} ?(?P<arguments>{arguments})$\n"
     r'(?P<options>(?:\1[ \t]*:[\w-]*:[^\n]*\n)+)?'
     r"(\1---\n(?P<yaml_options>(?:.+\n)*)\1---\n)?"
 )
+CODEBLOCK_END_TEMPLATE = r"(?<=\n){prefix}```+(:?\n|\Z)"
 
 
 def parse_yaml_options(lexed: Region) -> None:

tests/samples/myst-directive-nested.md

@@ -0,0 +1,13 @@
+````{note}
+The warning block will be properly-parsed
+
+   ```{warning}
+   Here's my warning
+   ```
+
+But the next block will be parsed as raw text
+
+    ```{warning}
+    Here's my raw text warning that isn't parsed...
+    ```
+````

tests/test_myst_lexers.py

@@ -311,3 +311,38 @@ def test_directive_no_trailing_newline():
             'source': 'flask\npyramid\ncustom\n',
         }),
     ])
+
+
+def test_directive_nested():
+    lexer = DirectiveLexer(directive='.+')
+    text = Path(sample_path('myst-directive-nested.md')).read_text().rstrip('\n')
+    compare(lex_text(text, lexer), expected=[
+        Region(0, 223, lexemes={
+            'directive': 'note',
+            'arguments': '',
+            'options': {},
+            'source': ('The warning block will be properly-parsed\n'
+                       '\n'
+                       '   ```{warning}\n'
+                       "   Here's my warning\n"
+                       '   ```\n'
+                       '\n'
+                       'But the next block will be parsed as raw text\n'
+                       '\n'
+                       '    ```{warning}\n'
+                       "    Here's my raw text warning that isn't parsed...\n"
+                       '    ```\n'),
+        }),
+        Region(54, 91, lexemes={
+            'directive': 'warning',
+            'arguments': '',
+            'options': {},
+            'source': "Here's my warning\n",
+        }),
+        Region(146, 215, lexemes={
+            'directive': 'warning',
+            'arguments': '',
+            'options': {},
+            'source': "Here's my raw text warning that isn't parsed...\n",
+        }),
+    ])