rustdoc: Move the "copy path" button out of the HTML and generate it with JS

src/librustdoc/html/static/css/noscript.css

@@ -9,7 +9,7 @@ rules.
 	margin-left: 0 !important;
 }
 
-#copy-path, #sidebar-button, .sidebar-resizer {
+#sidebar-button, .sidebar-resizer {
 	/* It requires JS to work so no need to display it in this case. */
 	display: none !important;
 }

src/librustdoc/html/static/js/main.js

@@ -2113,34 +2113,41 @@ function preLoadCss(cssUrl) {
         }, 1000);
     }
 
-    // Copy button that appears next to the path breadcrumbs.
-    const but = document.getElementById("copy-path");
-    if (!but) {
-        return;
-    }
-    but.onclick = () => {
-        // We get the path from the "breadcrumbs" and the actual item name.
-        let path = "";
-        // @ts-expect-error
-        const heading = document.getElementById(MAIN_ID).querySelector(".main-heading");
-
-        if (heading) {
-            const breadcrumbs = heading.querySelector(".rustdoc-breadcrumbs");
-            if (breadcrumbs) {
-                // @ts-expect-error
-                path = breadcrumbs.innerText;
-                if (path.length > 0) {
-                    path += "::";
+    const itemPath = nonnull(document.getElementById(MAIN_ID)).querySelector(".main-heading h1");
+    // The best way to check it's a page where we should generate the "copy path" button is to
+    // check if there is a `<span>` in the `<h1>`.
+    if (itemPath && itemPath.querySelector("span")) {
+        // Copy button that appears next to the path breadcrumbs.
+        const but = document.createElement("button");
+        but.id = "copy-path";
+        but.setAttribute("title", "Copy item path to clipboard");
+        but.innerText = "Copy item path";
+
+        but.onclick = () => {
+            const heading = nonnull(
+                document.getElementById(MAIN_ID)).querySelector(".main-heading");
+            if (heading) {
+                // We get the path from the "breadcrumbs" and the actual item name.
+                let path = "";
+
+                const breadcrumbs = heading.querySelector(".rustdoc-breadcrumbs");
+                if (breadcrumbs) {
+                    // @ts-expect-error
+                    path = breadcrumbs.innerText;
+                    if (path.length > 0) {
+                        path += "::";
+                    }
                 }
-            }
 
-            // @ts-expect-error
-            path += heading.querySelector("h1 > span").innerText;
+                // @ts-expect-error
+                path += heading.querySelector("h1 > span").innerText;
 
-            copyContentToClipboard(path);
-            copyButtonAnimation(but);
-        }
-    };
+                copyContentToClipboard(path);
+                copyButtonAnimation(but);
+            }
+        };
+        itemPath.appendChild(but);
+    }
 
     /**
      * Copy buttons on code examples.

src/librustdoc/html/templates/print_item.html

@@ -11,12 +11,9 @@
     {% endif %}
     <h1>
         {{typ}}
-        <span{% if item_type != "mod" +%} class="{{item_type}}"{% endif %}>
+        <span {% if item_type != "mod" +%} class="{{item_type}}"{% endif %}>
         {{name|wrapped|safe}}
         </span>&nbsp;{# #}
-        <button id="copy-path" title="Copy item path to clipboard"> {# #}
-            Copy item path {# #}
-        </button> {# #}
     </h1> {# #}
     <rustdoc-toolbar></rustdoc-toolbar> {# #}
     <span class="sub-heading">

tests/rustdoc-gui/copy-path.goml

@@ -1,12 +1,14 @@
-// Checks that the "copy path" button is not triggering JS error and its display
-// isn't broken and the copied path is as expected.
+// Checks that the "copy path" button is not triggering JS error and its display isn't broken and
+// the copied path is as expected. Also checks that the button is only present on the expected
+// pages.
 go-to: "file://" + |DOC_PATH| + "/test_docs/foreign_impl_order/trait.Foo.html"
 permissions: ["clipboard-read"]
 
 // We ensure that the clipboard is empty.
 assert-clipboard: ""
 
 // First we store the size of the button before we click on it.
+wait-for: "#copy-path"
 store-size: ("#copy-path", {"width": width, "height": height})
 click: "#copy-path"
 // We wait for the new text to appear.
@@ -22,6 +24,7 @@ assert-size: ("#copy-path:not(.clicked)", {"width": |width|, "height": |height|}
 
 // Check the path for a module.
 go-to: "file://" + |DOC_PATH| + "/test_docs/foreign_impl_order/index.html"
+wait-for: "#copy-path"
 click: "#copy-path"
 // We wait for the new text to appear.
 wait-for: "#copy-path.clicked"
@@ -30,8 +33,49 @@ assert-clipboard: "test_docs::foreign_impl_order"
 
 // Check the path for the crate.
 go-to: "file://" + |DOC_PATH| + "/test_docs/index.html"
+wait-for: "#copy-path"
 click: "#copy-path"
 // We wait for the new text to appear.
 wait-for: "#copy-path.clicked"
 // We check that the clipboard value is the expected one.
 assert-clipboard: "test_docs"
+
+// Now check the presence of the "copy code" button. Above we already checked for items, crate
+// and modules.
+define-function: ("check-copy-path-presence", [path], block {
+    go-to: "file://" + |DOC_PATH| + "/test_docs/" + |path|
+    wait-for: "#copy-path"
+})
+
+// Keyword
+call-function: ("check-copy-path-presence", {"path": "keyword.for.html"})
+// Attribute
+call-function: ("check-copy-path-presence", {"path": "attribute.forbid.html"})
+// Macro
+call-function: ("check-copy-path-presence", {"path": "macro.attr_macro.html"})
+// Constant
+call-function: ("check-copy-path-presence", {"path": "constant.CONST.html"})
+
+// And now we check its absence.
+define-function: ("check-copy-path-absence", [path], block {
+    go-to: "file://" + |DOC_PATH| + "/" + |path|
+    expect-failure: true
+    wait-for: "#copy-path"
+    expect-failure: false
+})
+
+// To prevent waiting for too long, we set the maximum time for "wait-for" to 1 second.
+set-timeout: 1000
+
+// Source code page.
+call-function: ("check-copy-path-absence", {"path": "src/test_docs/lib.rs.html"})
+// Settings page.
+call-function: ("check-copy-path-absence", {"path": "settings.html"})
+// Help page.
+call-function: ("check-copy-path-absence", {"path": "help.html"})
+// All items page.
+call-function: ("check-copy-path-absence", {"path": "test_docs/all.html"})
+
+// Check the button is not present if javascript is disabled (since it's generated with JS...).
+javascript: false
+call-function: ("check-copy-path-absence", {"path": "test_docs/index.html"})