Fix type checking

rich/syntax.py

@@ -321,7 +321,7 @@ def from_path(
         )
 
     @classmethod
-    def guess_lexer(cls, path: AnyStr, code: Optional[str] = None) -> str:
+    def guess_lexer(cls, path: str, code: Optional[str] = None) -> str:
         """Guess the alias of the Pygments lexer to use based on a path and an optional string of code.
         If code is supplied, it will use a combination of the code and the filename to determine the
         best lexer to use. For example, if the file is ``index.html`` and the file contains Django
@@ -341,7 +341,7 @@ def guess_lexer(cls, path: AnyStr, code: Optional[str] = None) -> str:
         lexer_name = "default"
         if code:
             try:
-                lexer: Lexer = guess_lexer_for_filename(path, code)
+                lexer = guess_lexer_for_filename(path, code)
             except ClassNotFound:
                 pass
 
@@ -399,7 +399,9 @@ def lexer(self) -> Optional[Lexer]:
             return None
 
     def highlight(
-        self, code: str, line_range: Optional[Tuple[int, int]] = None
+        self,
+        code: str,
+        line_range: Optional[Tuple[Optional[int], Optional[int]]] = None,
     ) -> Text:
         """Highlight code and return a Text instance.
 
@@ -447,7 +449,7 @@ def tokens_to_spans() -> Iterable[Tuple[str, Optional[Style]]]:
                     """Convert tokens to spans."""
                     tokens = iter(line_tokenize())
                     line_no = 0
-                    _line_start = line_start - 1
+                    _line_start = line_start - 1 if line_start else 0
 
                     # Skip over tokens until line start
                     while line_no < _line_start:
@@ -460,7 +462,7 @@ def tokens_to_spans() -> Iterable[Tuple[str, Optional[Style]]]:
                         yield (token, _get_theme_style(token_type))
                         if token.endswith("\n"):
                             line_no += 1
-                            if line_no >= line_end:
+                            if line_end and line_no >= line_end:
                                 break
 
                 text.append_tokens(tokens_to_spans())
@@ -543,11 +545,6 @@ def __rich_console__(
             else self.code_width
         )
 
-        line_offset = 0
-        if self.line_range:
-            start_line, end_line = self.line_range
-            line_offset = max(0, start_line - 1)
-
         ends_on_nl = self.code.endswith("\n")
         code = self.code if ends_on_nl else self.code + "\n"
         code = textwrap.dedent(code) if self.dedent else code
@@ -589,6 +586,10 @@ def __rich_console__(
                     yield from syntax_line
             return
 
+        start_line, end_line = self.line_range or (None, None)
+        line_offset = 0
+        if start_line:
+            line_offset = max(0, start_line - 1)
         lines: Union[List[Text], Lines] = text.split("\n", allow_blank=ends_on_nl)
         if self.line_range:
             lines = lines[line_offset:end_line]