Fix the 'Expand All' button in the all-site ToC (#56439)

Co-authored-by: Sarah Schneider <sarahs@github.com>

Author: hubwriter

src/dev-toc/README.md

@@ -1,3 +1,33 @@
 # Developer table of contents
 
 This directory generates a full table of contents for the docs.github.com site.
+
+<img src="toc-screenshot.png" width=30% style="padding-bottom: 2em" />
+
+The table of contents is generated locally within the `static` subdirectory as a series of `index.html` files, within version subdirectories such as `free-pro-team@latest` and `enterprise-cloud@latest` etc.
+
+## Generating the table of contents
+
+To generate the table of contents, run the following command from the Terminal:
+
+```bash
+npm run dev-toc
+```
+
+After generating the files, the ToC should open in your default browser. If it doesn't, open your browser and naviate to `file:///PATH/TO/docs-internal/src/dev-toc/static/free-pro-team@latest/index.html`.
+
+## Generating the ToC with one or more sections auto-expanded
+
+Alternatively, you can generate the table of contents with a specific top-level section of the docs auto-expanded by running the following command:
+
+```bash
+tsx src/dev-toc/generate.ts -o PRODUCT-ID [PRODUCT-ID PRODUCT-ID ...]
+```
+
+where `PRODUCT-ID` is the first part of the URL for the top-level section of the docs. For example, the `actions` section of the docs has the URL `https://docs.github.com/en/actions`, so the `PRODUCT-ID` is `actions`. So the command would be:
+
+```bash
+tsx src/dev-toc/generate.ts -o actions
+```
+
+Note: if you generate the table more than once, with a different product ID flag you will need to refresh the page to see the changes.

src/dev-toc/index.ts

@@ -61,7 +61,17 @@ <h2 class="mt-3 mb-3"><abbr>TOC</abbr> for {{ allVersions[currentVersion].versio
 {% endfor %}
 {% endif %}
 
-<script src="../../index.js"></script>
+<script>
+const expandBtn = document.querySelector('.js-expand');
+expandBtn?.addEventListener('click', function() {
+  const details = document.querySelectorAll('details');
+  const shouldExpand = expandBtn.textContent.trim() === 'Expand All';
+  details.forEach(detail => {
+    detail.open = shouldExpand;
+  });
+  expandBtn.textContent = shouldExpand ? 'Collapse All' : 'Expand All';
+});
+</script>
 </main>
 </body>
 </html>