From 1522b0e2dca4378a98a534b07b09b7e0859f7e2a Mon Sep 17 00:00:00 2001
From: glacambre <code@lacamb.re>
Date: Fri, 26 Jan 2024 18:56:17 +0100
Subject: [PATCH] lib/tabs.ts: enable accessing all tabs through `tri.tabs`

---
 src/excmds.ts   | 16 +++++++++++++---
 src/lib/tabs.ts | 15 ++++++---------
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/src/excmds.ts b/src/excmds.ts
index 114974c5..a76ae610 100644
--- a/src/excmds.ts
+++ b/src/excmds.ts
@@ -5890,9 +5890,19 @@ export async function js(...str: string[]) {
  * - Get the URL of the tab whose id 3:
  *   `:jsb tri.tabs[3].location.href.then(console.log)`
  * - Set the title of the tab whose id is 6:
- *   `:jsb tri.tabs[3].document.title = "New title!"`
- * - Run `alert()` in all tabs:
- *   `:jsb browser.tabs.query({}).then(tabs => tabs.forEach(tab => tri.tabs[tab.id].tri.excmds.js('alert()')))`
+ *   `:jsb tri.tabs[6].document.title = "New title!"`
+ * - Run `alert()` in a tab whose id is 9:
+ *   `:jsb tri.tabs[9].alert()`
+ *
+ * You can also directly access the corresonding property in all tabs by using
+ * the "tabs" object itself, e.g.
+ *
+ * - Build a string containing the id of the active element of each tab:
+ *   `:jsb tri.tabs.document.activeElement.id.then(ids => ids.reduce(s, id => s + " " + id))`
+ * - Scroll all tabs to the tenth pixel:
+ *   `:jsb tri.tabs.document.documentElement.scrollTop = 10`
+ * - Use tridactyl's JS ex command to perform a complex computation:
+ *   `:jsb tri.tabs.tri.excmds.js("let x = 1; let y = 2; x + y").then(console.log)`
  *
  * When fetching a value or running a function in a tab through the `tabs` property, the returned value is a Promise and must be awaited.
  * Setting values through the `tab` property is asynchronous too and there is no way to await this operation.
diff --git a/src/lib/tabs.ts b/src/lib/tabs.ts
index 63ea917a..7339ef4b 100644
--- a/src/lib/tabs.ts
+++ b/src/lib/tabs.ts
@@ -2,9 +2,6 @@ import * as Messaging from "@src/lib/messaging"
 
 const allTabs = -1
 
-// Small wrapper meant to enable sending a message either to a single tab or
-// multiple ones. Note that for now, sending messages to all tabs does not
-// work, for reasons unknown.
 const msg = (tabId, ...args) => {
     if (tabId === allTabs) {
         return Messaging.messageAllTabs("omniscient_content", ...args)
@@ -80,11 +77,11 @@ export const tabsProxy = new Proxy(Object.create(null), {
             // for a single tab
             return tabProxy(id, [])
         }
-        throw Error("Foreground tabs proxy needs to be indexed by tab ID.")
-        // Ideally, if p is a string, we should construct a proxy for all
-        // existing tabs. This unfortunately does not seem to work:
-        // Messaging.messageAllTab seems to return an array of undefined when
-        // running e.g. `tabs.document.title`.
-        // return tabProxy(allTabs, []);
+        if (typeof p === "string") {
+            // If `p` is a string, then we return a proxy with a sentinel value
+            // indicating that the request should be sent to all tabs instead.
+            return tabProxy(allTabs, [])[p]
+        }
+        throw new Error(`'tabs' object can only be accessed by a number (e.g. tabs[3]) or a string (e.g. tabs.document or tabs['document']). Type of accessor: "${typeof p}"`)
     },
 })