Auto merge of #106215 - matthiaskrgr:rollup-53r89ww, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #106028 (docs/test: add UI test and long-form error docs for `E0461`)
 - #106172 (Suggest `impl Iterator` when possible for `_` return type)
 - #106173 (Deduplicate `op` methods)
 - #106176 (Recover `fn` keyword as `Fn` trait in bounds)
 - #106194 (rustdoc: combine common sidebar background color CSS rules)
 - #106199 (Silence knock-down errors on `[type error]` bindings)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 46 insertions, 1 deletions

diff --git a/src/test/rustdoc-gui/sidebar-source-code.goml b/src/test/rustdoc-gui/sidebar-source-code.goml
index 36e4d555b8e..d5f57ed6102 100644
--- a/src/test/rustdoc-gui/sidebar-source-code.goml
+++ b/src/test/rustdoc-gui/sidebar-source-code.goml
@@ -1,7 +1,52 @@
 // The goal of this test is to ensure that the sidebar is working as expected in the source
 // code pages.
 goto: "file://" + |DOC_PATH| + "/src/test_docs/lib.rs.html"
-// First: desktop mode.
+show-text: true
+
+// First, check the sidebar colors.
+define-function: (
+    "check-colors",
+    (theme, color, background_color),
+    [
+        ("local-storage", {
+            "rustdoc-theme": |theme|,
+            "rustdoc-use-system-theme": "false",
+        }),
+        ("reload"),
+        // Checking results colors.
+        ("assert-css", (".source .sidebar", {
+        	"color": |color|,
+        	"background-color": |background_color|
+        }, ALL)),
+    ],
+)
+
+call-function: (
+	"check-colors",
+	{
+		"theme": "ayu",
+		"color": "rgb(197, 197, 197)",
+		"background_color": "rgb(20, 25, 31)",
+	}
+)
+call-function: (
+	"check-colors",
+	{
+		"theme": "dark",
+		"color": "rgb(221, 221, 221)",
+		"background_color": "rgb(80, 80, 80)",
+	}
+)
+call-function: (
+	"check-colors",
+	{
+		"theme": "light",
+		"color": "rgb(0, 0, 0)",
+		"background_color": "rgb(245, 245, 245)",
+	}
+)
+
+// Next, desktop mode layout.
 size: (1100, 800)
 // We check that the sidebar isn't expanded and has the expected width.
 assert-css: ("nav.sidebar", {"width": "50px"})