Merge pull request #3334 from pawamoy/goto-anchor-returns-bool

Return a boolean from `Markdown.goto_anchor`

CHANGELOG.md

@@ -18,6 +18,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed the command palette crashing with a `TimeoutError` in any Python before 3.11 https://github.com/Textualize/textual/issues/3320
 - Fixed `Input` event leakage from `CommandPalette` to `App`.
 
+### Changed
+
+- Breaking change: Changed `Markdown.goto_anchor` to return a boolean (if the anchor was found) instead of `None` https://github.com/Textualize/textual/pull/3334
+
 ## [0.37.0] - 2023-09-15
 
 ### Added

src/textual/widgets/_markdown.py

@@ -660,7 +660,7 @@ def sanitize_location(location: str) -> tuple[Path, str]:
         location, _, anchor = location.partition("#")
         return Path(location), anchor
 
-    def goto_anchor(self, anchor: str) -> None:
+    def goto_anchor(self, anchor: str) -> bool:
         """Try and find the given anchor in the current document.
 
         Args:
@@ -673,14 +673,18 @@ def goto_anchor(self, anchor: str) -> None:
 
             Note that the slugging method used is similar to that found on
             GitHub.
+
+        Returns:
+            True when the anchor was found in the current document, False otherwise.
         """
         if not self._table_of_contents or not isinstance(self.parent, Widget):
-            return
+            return False
         unique = TrackedSlugs()
         for _, title, header_id in self._table_of_contents:
             if unique.slug(title) == anchor:
                 self.parent.scroll_to_widget(self.query_one(f"#{header_id}"), top=True)
-                return
+                return True
+        return False
 
     async def load(self, path: Path) -> None:
         """Load a new Markdown document.

tests/test_markdown.py

@@ -125,3 +125,18 @@ async def test_load_non_existing_file() -> None:
             await pilot.app.query_one(Markdown).load(
                 Path("---this-does-not-exist---.it.is.not.a.md")
             )
+
+
+@pytest.mark.parametrize(
+    ("anchor", "found"),
+    [
+        ("hello-world", False),
+        ("hello-there", True),
+    ]
+)
+async def test_goto_anchor(anchor: str, found: bool) -> None:
+    """Going to anchors should return a boolean: whether the anchor was found."""
+    document = "# Hello There\n\nGeneral.\n"
+    async with MarkdownApp(document).run_test() as pilot:
+        markdown = pilot.app.query_one(Markdown)
+        assert markdown.goto_anchor(anchor) is found