Accept Promise<Target>

[fregante]

Targeting the sidebar from the content script requires knowing its own tabId. That is currently still only possible by asking the runtime. This means we can't define a static target like before:

const target = { page: "/sidebar.html" };

+ // Potential race condition
+ void getThisFrame().then((frame) => {
+   target.page += "?tabId=" + frame.tabId;
+});

const sidebarInThisTab = {
  renderPanels: getMethod("SIDEBAR_RENDER_PANELS", target),
// etc

With this change, it would be possible to write:

const target = getThisFrame().then((frame) => ({ page: "/sidebar.html?tabId=" + frame.tabId })

const sidebarInThisTab = {
  renderPanels: getMethod("SIDEBAR_RENDER_PANELS", target),
// etc

Related:

• request: allow to retrieve a tabId and documentId from the content script w3c/webextensions#469
• https://github.com/pixiebrix/pixiebrix-extension/pull/7320/files#diff-74d7ef496f52cfd5c735c367dc49bfcd29ef6259099952c44da2f077b37eed12R26