Add regression test for hamberger button color in mobile sidebar

Author: GuillaumeGomez

src/test/rustdoc-gui/sidebar-mobile.goml

@@ -42,23 +42,24 @@ scroll-to: ".block.keyword li:nth-child(1)"
 compare-elements-position-near: (".block.keyword li:nth-child(1)", ".mobile-topbar", {"y": 543})
 
 // Now checking the background color of the sidebar.
+show-text: true
 local-storage: {"rustdoc-use-system-theme": "false", "rustdoc-theme": "dark"}
 reload:
 
 // Open the sidebar menu.
 click: ".sidebar-menu-toggle"
-assert-css: (".sidebar", {"background-color": "rgb(80, 80, 80)"})
+assert-css: (".sidebar", {"background-color": "rgb(80, 80, 80)", "color": "rgb(221, 221, 221)"})
 
 local-storage: {"rustdoc-use-system-theme": "false", "rustdoc-theme": "ayu"}
 reload:
 
 // Open the sidebar menu.
 click: ".sidebar-menu-toggle"
-assert-css: (".sidebar", {"background-color": "rgb(20, 25, 31)"})
+assert-css: (".sidebar", {"background-color": "rgb(20, 25, 31)", "color": "rgb(197, 197, 197)"})
 
 local-storage: {"rustdoc-use-system-theme": "false", "rustdoc-theme": "light"}
 reload:
 
 // Open the sidebar menu.
 click: ".sidebar-menu-toggle"
-assert-css: (".sidebar", {"background-color": "rgb(245, 245, 245)"})
+assert-css: (".sidebar", {"background-color": "rgb(245, 245, 245)", "color": "rgb(0, 0, 0)"})