Method on_mount

tests/snapshot_tests/test_snapshots.py:4416–4420

(self)

            yield Markdown()

        async def on_mount(self) -> None:
            markdown = self.query_one(Markdown)
            for line in MD:
                await markdown.append(line)
                await asyncio.sleep(0.01)

    assert snap_compare(MDApp(), press=["1", "wait:500"])