Use render instead of render_lines in Opacity, add tests

src/textual/renderables/opacity.py

@@ -1,13 +1,9 @@
 import functools
-from time import sleep
 
 from rich.color import Color
 from rich.console import ConsoleOptions, Console, RenderResult, RenderableType
-from rich.live import Live
-from rich.panel import Panel
 from rich.segment import Segment
 from rich.style import Style
-from rich.text import Text
 
 from textual.renderables.utilities import blend_colors
 
@@ -27,26 +23,24 @@ class Opacity:
     def __rich_console__(
         self, console: Console, options: ConsoleOptions
     ) -> RenderResult:
-        lines = console.render_lines(self.renderable, options)
+        segments = console.render(self.renderable, options)
         opacity = self.value
-        for line in lines:
-            for segment in line:
-                style = segment.style
-                if not style:
-                    yield segment
-                    continue
-                fg, bg = style.color, style.bgcolor
-                if fg and fg.triplet and bg and bg.triplet:
-                    yield Segment(
-                        text=segment.text,
-                        style=_get_blended_style_cached(
-                            fg_color=fg, bg_color=bg, opacity=opacity
-                        ),
-                        control=segment.control,
-                    )
-                else:
-                    yield segment
-            yield ""
+        for segment in segments:
+            style = segment.style
+            if not style:
+                yield segment
+                continue
+            fg, bg = style.color, style.bgcolor
+            if fg and fg.triplet and bg and bg.triplet:
+                yield Segment(
+                    text=segment.text,
+                    style=_get_blended_style_cached(
+                        fg_color=fg, bg_color=bg, opacity=opacity
+                    ),
+                    control=segment.control,
+                )
+            else:
+                yield segment
 
 
 @functools.lru_cache(maxsize=1024)
@@ -60,6 +54,12 @@ def _get_blended_style_cached(
 
 
 if __name__ == "__main__":
+    from rich.live import Live
+    from rich.panel import Panel
+    from rich.text import Text
+
+    from time import sleep
+
     console = Console()
 
     panel = Panel.fit(

tests/renderables/test_opacity.py

@@ -4,28 +4,47 @@ from rich.text import Text
 from tests.utilities.render import render
 from textual.renderables.opacity import Opacity
 
-
-@pytest.mark.skip
-def test_simple_opacity():
-    text = Text("Hello, world!", style="#ff0000 on #00ff00")
-    assert render(Opacity(text, value=.5)) == ""
+STOP = "\x1b[0m"
 
 
-@pytest.mark.skip
-def test_ansi_colors_ignored():
-    pass
+@pytest.fixture
+def text():
+    return Text("Hello, world!", style="#ff0000 on #00ff00", end="")
 
 
-@pytest.mark.skip
-def test_opacity_no_style():
-    pass
+def test_simple_opacity(text):
+    blended_red_on_green = "\x1b[38;2;127;127;0;48;2;0;255;0m"
+    assert render(Opacity(text, value=.5)) == (
+        f"{blended_red_on_green}Hello, world!{STOP}"
+    )
 
 
-@pytest.mark.skip
-def test_opacity_only_fg():
-    pass
+def test_value_zero_sets_foreground_color_to_background_color(text):
+    foreground = background = "0;255;0"
+    assert render(Opacity(text, value=0)) == (
+        f"\x1b[38;2;{foreground};48;2;{background}mHello, world!{STOP}"
+    )
 
 
-@pytest.mark.skip
-def test_opacity_only_bg():
-    pass
+def test_opacity_value_of_one_noop(text):
+    assert render(Opacity(text, value=1)) == render(text)
+
+
+def test_ansi_colors_noop():
+    ansi_colored_text = Text("Hello, world!", style="red on green", end="")
+    assert render(Opacity(ansi_colored_text, value=.5)) == render(ansi_colored_text)
+
+
+def test_opacity_no_style_noop():
+    text_no_style = Text("Hello, world!", end="")
+    assert render(Opacity(text_no_style, value=.2)) == render(text_no_style)
+
+
+def test_opacity_only_fg_noop():
+    text_only_fg = Text("Hello, world!", style="#ff0000", end="")
+    assert render(Opacity(text_only_fg, value=.5)) == render(text_only_fg)
+
+
+def test_opacity_only_bg_noop():
+    text_only_bg = Text("Hello, world!", style="on #ff0000", end="")
+    assert render(Opacity(text_only_bg, value=.5)) == render(text_only_bg)

tests/utilities/render.py

@@ -19,6 +19,7 @@ def render(renderable: RenderableType, no_wrap: bool = False) -> str:
     console = Console(
         width=100, file=io.StringIO(), color_system="truecolor", legacy_windows=False
     )
-    console.print(renderable, no_wrap=no_wrap)
-    output = replace_link_ids(console.file.getvalue())
+    with console.capture() as capture:
+        console.print(renderable, no_wrap=no_wrap, end="")
+    output = replace_link_ids(capture.get())
     return output