#885 disables move tab to a new window when only one tab is opened

src/js/popup.js

@@ -212,6 +212,11 @@ const Logic = {
     return false;
   },
 
+  async noOfTabs() {
+    const activeTabs = await browser.tabs.query({windowId: browser.windows.WINDOW_ID_CURRENT});
+    return activeTabs.length;
+  },
+
   async refreshIdentities() {
     const [identities, state] = await Promise.all([
       browser.contextualIdentities.query({}),
@@ -716,6 +721,10 @@ Logic.registerPanel(P_CONTAINER_INFO, {
         incompatEl.classList.add("container-info-tab-row");
 
         moveTabsEl.parentNode.insertBefore(fragment, moveTabsEl.nextSibling);
+      } else {
+        Logic.noOfTabs().then(result => {
+          if (result === 1) {
+            moveTabsEl.classList.remove("clickable");
           } else {
             Logic.addEnterHandler(moveTabsEl, async function () {
               await browser.runtime.sendMessage({
@@ -726,6 +735,10 @@ Logic.registerPanel(P_CONTAINER_INFO, {
               window.close();
             });
           }
+        }).catch(error => {
+          throw new Error(error);
+        });
+      }
     } catch (e) {
       throw new Error("Could not check for incompatible add-ons.");
     }