Rollup merge of rust-lang#102491 - notriddle:notriddle/sidebar-opacity, r=GuillaumeGomez

rustdoc: remove no-op source sidebar `opacity`

These rules were added in dc2c972 to work with CSS transitions. They're otherwise redundant, since the `visibility` property already hides everything.

https://github.com/rust-lang/rust/blob/dc2c9723343c985740be09919236a6e96c4e4433/src/librustdoc/html/static/css/rustdoc.css#L350-L354

The transition was remove with 237d625, but the now-redundant `opacity` property was not.

Author: matthiaskrgr

Diff for: src/librustdoc/html/static/css/rustdoc.css

@@ -448,7 +448,6 @@ img {
 }
 
 .source .sidebar > *:not(#sidebar-toggle) {
-	opacity: 0;
 	visibility: hidden;
 }
 
@@ -457,7 +456,6 @@ img {
 }
 
 .source-sidebar-expanded .source .sidebar > *:not(#sidebar-toggle) {
-	opacity: 1;
 	visibility: visible;
 }
 

Diff for: src/test/rustdoc-gui/sidebar-source-code-display.goml

@@ -3,20 +3,17 @@ javascript: false
 goto: file://|DOC_PATH|/src/test_docs/lib.rs.html
 // Since the javascript is disabled, there shouldn't be a toggle.
 assert-false: "#sidebar-toggle"
-// For some reason, we need to wait a bit here because it seems like the transition on opacity
-// is being applied whereas it can't be reproduced in a browser...
-wait-for-css: (".sidebar > *", {"visibility": "hidden", "opacity": 0})
+wait-for-css: (".sidebar > *", {"visibility": "hidden"})
 
 // Let's retry with javascript enabled.
 javascript: true
 reload:
 wait-for: "#sidebar-toggle"
-assert-css: ("#sidebar-toggle", {"visibility": "visible", "opacity": 1})
-assert-css: (".sidebar > *:not(#sidebar-toggle)", {"visibility": "hidden", "opacity": 0})
+assert-css: ("#sidebar-toggle", {"visibility": "visible"})
+assert-css: (".sidebar > *:not(#sidebar-toggle)", {"visibility": "hidden"})
 // Let's expand the sidebar now.
 click: "#sidebar-toggle"
-// Because of the transition CSS, we check by using `wait-for-css` instead of `assert-css`.
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible", "opacity": 1})
+wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
 
 // We now check that opening the sidebar and clicking a link will leave it open.
 // The behavior here on desktop is different than the behavior on mobile,
@@ -36,7 +33,7 @@ show-text: true
 local-storage: {"rustdoc-theme": "light", "rustdoc-use-system-theme": "false"}
 reload:
 // Waiting for the sidebar to be displayed...
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible", "opacity": 1})
+wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
 assert-css: (
     "#source-sidebar details[open] > .files a.selected",
     {"color": "rgb(0, 0, 0)", "background-color": "rgb(255, 255, 255)"},
@@ -91,7 +88,7 @@ assert-css: (
 local-storage: {"rustdoc-theme": "dark", "rustdoc-use-system-theme": "false"}
 reload:
 // Waiting for the sidebar to be displayed...
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible", "opacity": 1})
+wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
 assert-css: (
     "#source-sidebar details[open] > .files > a.selected",
     {"color": "rgb(221, 221, 221)", "background-color": "rgb(51, 51, 51)"},
@@ -146,7 +143,7 @@ assert-css: (
 local-storage: {"rustdoc-theme": "ayu", "rustdoc-use-system-theme": "false"}
 reload:
 // Waiting for the sidebar to be displayed...
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible", "opacity": 1})
+wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
 assert-css: (
     "#source-sidebar details[open] > .files a.selected",
     {"color": "rgb(255, 180, 76)", "background-color": "rgb(20, 25, 31)"},
@@ -201,7 +198,7 @@ assert-css: (
 size: (500, 700)
 reload:
 // Waiting for the sidebar to be displayed...
-wait-for-css: ("#sidebar-toggle", {"visibility": "visible", "opacity": 1})
+wait-for-css: ("#sidebar-toggle", {"visibility": "visible"})
 
 // We now check it takes the full size of the display.
 assert-property: ("body", {"clientWidth": "500", "clientHeight": "700"})