snapshot

Author: willmcgugan

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Added
+
+- Added a 'stream' layout, which is a lot like vertical but with fewer supported rules (which is why it is faster)
+
 ## [5.1.1] - 2025-07-21
 
 ### Fixed

src/textual/layouts/stream.py

@@ -33,8 +33,8 @@ def arrange(
         placements: list[WidgetPlacement] = []
         width = size.width
         first_child_styles = children[0].styles
-        y = first_child_styles.margin.top
-        previous_margin = 0
+        y = 0
+        previous_margin = first_child_styles.margin.top
         null_offset = NULL_OFFSET
 
         for widget in children:

tests/snapshot_tests/test_snapshots.py

@@ -4505,11 +4505,19 @@ def compose(self) -> ComposeResult:
 
 
 def test_stream_layout(snap_compare):
-    """Test stream layout."""
+    """Test stream layout.
+
+    You should see 3 blue labels.
+    The topmost should be a single line.
+    The middle should be two lines.
+    The last should be three lines.
+    There will be a one character margin between them.
+
+    """
 
     class StreamApp(App):
         CSS = """
-        VerticalScroll {
+        VerticalScroll {            
             layout: stream;
             Label {
                 background: blue;