dm: make a selected recipient the active conversation in the right pane

Clicking "Message" added the user to the sidebar list but the right-hand
message pane stayed on the previously-active conversation. setDirectMessageRecipient
called setFocusedDmConversation (which only tracks read-state) and never set
activeDmConversationId — the value buildDmConversationData reads to choose which
thread the right pane renders — so it kept resolving the stale id.

Set activeDmConversationId directly (mirroring handleDmConversationSelect), and
switch the mobile pane to the thread for explicit selections (not the auto
thread-default).

Regression: tests/ui/dm-set-recipient-active.test.mjs.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

js/ui/profileModal/ProfileDirectMessageController.js

@@ -242,15 +242,24 @@ export class ProfileDirectMessageController {
     this.updateMessageThreadSelection(nextRecipient);
 
     if (nextRecipient) {
-      // Focus this recipient's conversation so a freshly-selected recipient
-      // (e.g. the "Message" button for someone with no existing thread) isn't
-      // overridden by a stale activeDmConversationId pointing at the top of the
-      // inbox.
+      // Make this recipient's conversation the active one so a freshly-selected
+      // recipient (e.g. the "Message" button for someone with no existing
+      // thread) isn't overridden by a stale activeDmConversationId pointing at
+      // the top of the inbox. setFocusedDmConversation only tracks read-state —
+      // activeDmConversationId is what buildDmConversationData reads to decide
+      // which thread the right-hand pane renders, so set it directly (mirroring
+      // handleDmConversationSelect).
       const actor = this.helper.resolveActiveDmActor();
       const conversationId = actor
         ? this.helper.buildDmConversationId(actor, nextRecipient)
         : "";
       if (conversationId) {
+        this.activeDmConversationId = conversationId;
+        // Selecting a recipient explicitly (not the auto thread-default) means
+        // the user wants to see that thread — switch the mobile pane to it too.
+        if (reason !== "thread-default") {
+          this.dmMobileView = "thread";
+        }
         this.setFocusedDmConversation(conversationId);
       }
       void this.helper.ensureDmRecipientData(nextRecipient);

tests/ui/dm-set-recipient-active.test.mjs

@@ -0,0 +1,94 @@
+// Regression: clicking the "Message" button added the user to the sidebar but
+// the right-hand message pane stayed on the previously-active conversation.
+// setDirectMessageRecipient relied on setFocusedDmConversation (which only
+// tracks read-state) and never updated activeDmConversationId — the value
+// buildDmConversationData reads to decide which thread the right pane renders.
+//
+// Scenario (SCN-dm-select-makes-active):
+//   Given a controller whose activeDmConversationId points at an old thread,
+//   When a new recipient is selected via setDirectMessageRecipient,
+//   Then activeDmConversationId becomes the new recipient's conversation id
+//     (so the right pane switches), and the mobile pane shows the thread.
+
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { ProfileDirectMessageController } from "../../js/ui/profileModal/ProfileDirectMessageController.js";
+
+// The method does `instanceof HTMLElement` guards; the stubbed DOM refs are null,
+// so the constructor just needs the global to exist.
+if (typeof globalThis.HTMLElement === "undefined") {
+  globalThis.HTMLElement = class HTMLElement {};
+}
+
+const ACTOR = "a".repeat(64);
+const OLD = "b".repeat(64);
+const NEW = "c".repeat(64);
+
+function makeFakeController() {
+  const focusCalls = [];
+  return {
+    activeDmConversationId: `dm:${[ACTOR, OLD].sort().join(":")}`,
+    dmMobileView: "list",
+    dmPrivacyToggleTouched: true,
+    directMessagesCache: [],
+    focusCalls,
+    mainController: {
+      normalizeHexPubkey: (v) => (typeof v === "string" && v.trim() ? v.trim() : ""),
+      state: { setDmRecipient: () => {} },
+    },
+    helper: {
+      resolveActiveDmActor: () => ACTOR,
+      buildDmConversationId: (actor, remote) =>
+        `dm:${[actor, remote].sort().join(":")}`,
+      ensureDmRecipientData: () => {},
+    },
+    renderer: {
+      profileMessagesList: null,
+      dmAppShellContainer: null,
+      setMessagesAnnouncement: () => {},
+      renderDirectMessageConversation: () => {},
+      renderDmAppShell: () => {},
+    },
+    updateMessageThreadSelection() {},
+    setFocusedDmConversation(id) {
+      focusCalls.push(id);
+    },
+  };
+}
+
+test("selecting a recipient makes its conversation active in the right pane", () => {
+  const ctx = makeFakeController();
+  const expectedId = `dm:${[ACTOR, NEW].sort().join(":")}`;
+
+  const result = ProfileDirectMessageController.prototype.setDirectMessageRecipient.call(
+    ctx,
+    NEW,
+    { reason: "external" },
+  );
+
+  assert.equal(result, NEW, "returns the normalized recipient");
+  assert.equal(
+    ctx.activeDmConversationId,
+    expectedId,
+    "activeDmConversationId must move to the selected recipient (not stay on the old thread)",
+  );
+  assert.equal(ctx.dmMobileView, "thread", "mobile pane switches to the thread");
+  assert.deepEqual(
+    ctx.focusCalls,
+    [expectedId],
+    "still tracks read-state for the focused conversation",
+  );
+});
+
+test("the auto thread-default does not force the mobile thread view", () => {
+  const ctx = makeFakeController();
+  ProfileDirectMessageController.prototype.setDirectMessageRecipient.call(ctx, NEW, {
+    reason: "thread-default",
+  });
+  assert.equal(
+    ctx.dmMobileView,
+    "list",
+    "thread-default keeps the inbox list visible on mobile",
+  );
+});