fix(tui): handle composed Option-D in model picker

Author: bwachman

src/tui/product-host.test.ts

@@ -650,6 +650,53 @@ describe("flat type-to-filter model picker", () => {
     }
   });
 
+  test("composed Option+D (∂) sets the default instead of filtering the model picker", async () => {
+    const defaults: string[] = [];
+    const { harness, host } = await mountPicker({
+      onSetDefault: (id) => defaults.push(id),
+    });
+    try {
+      host.openModels?.();
+      await harness.renderOnce();
+      const composed = {
+        name: "∂",
+        sequence: "∂",
+        ctrl: false,
+        meta: false,
+        option: false,
+      } as KeyEvent;
+      expect(handleListFilterKey(host.shell, composed)).toBe(false);
+      expect(runOverlayAction(host.shell, composed)).toBe(true);
+      expect(defaults).toEqual(["codex/abk-labs:gpt-5.5"]);
+      expect(host.shell.overlayItems).not.toEqual(["(no matches)"]);
+    } finally {
+      host.dispose();
+      harness.destroy();
+    }
+  });
+
+  test("composed Option+D (∂) remains filter text when setting a default is unavailable", async () => {
+    const { harness, host } = await mountPicker();
+    try {
+      host.openModels?.();
+      await harness.renderOnce();
+      const composed = {
+        name: "∂",
+        sequence: "∂",
+        ctrl: false,
+        meta: false,
+        option: false,
+      } as KeyEvent;
+      expect(handleListFilterKey(host.shell, composed)).toBe(true);
+      await harness.renderOnce();
+      expect(host.shell.overlayItems).toEqual(["(no matches)"]);
+      expect(runOverlayAction(host.shell, composed)).toBe(false);
+    } finally {
+      host.dispose();
+      harness.destroy();
+    }
+  });
+
   test("Alt+D on the no-matches sentinel does not set a default", async () => {
     const defaults: string[] = [];
     const { harness, host } = await mountPicker({
@@ -663,8 +710,35 @@ describe("flat type-to-filter model picker", () => {
       }
       await harness.renderOnce();
       expect(host.shell.overlayItems).toEqual(["(no matches)"]);
-      expect(runOverlayAction(host.shell, altD)).toBe(false);
+      expect(runOverlayAction(host.shell, altD)).toBe(true);
+      expect(defaults).toEqual([]);
+      expect(host.shell.overlayKind).toBe("model_picker");
+    } finally {
+      host.dispose();
+      harness.destroy();
+    }
+  });
+
+  test("composed Option+D (∂) on the no-matches sentinel does not reach the prompt", async () => {
+    const defaults: string[] = [];
+    const { harness, host } = await mountPicker({
+      onSetDefault: (id) => defaults.push(id),
+    });
+    try {
+      host.shell.prompt.value = "draft";
+      host.openModels?.();
+      await harness.renderOnce();
+      for (const ch of "zzzz-no-such-model") {
+        harness.pressKey(ch);
+      }
+      await harness.renderOnce();
+      expect(host.shell.overlayItems).toEqual(["(no matches)"]);
+
+      harness.pressKey("∂");
+      await harness.renderOnce();
+
       expect(defaults).toEqual([]);
+      expect(host.shell.prompt.value).toBe("draft");
       expect(host.shell.overlayKind).toBe("model_picker");
     } finally {
       host.dispose();

src/tui/product-host.ts

@@ -61,6 +61,7 @@ import {
 import { setOwnedOverlayItems } from "./shell/overlay-host.js";
 import {
   isAddProviderShortcutKey,
+  isSetDefaultShortcutKey,
   setPaletteCatalog,
 } from "./shell/palette.js";
 import { surfaceSystemNotice } from "./shell/prompt.js";
@@ -670,18 +671,26 @@ export async function mountProductHost(
                   openAddProvider({ returnToModels: true });
                   return true;
                 }
-                if (!(key.meta || key.option)) return false;
+                // Alt+F stays modifier-only; the default shortcut also accepts
+                // the composed Option+D glyph through its scoped predicate.
                 const name =
                   typeof key.name === "string" ? key.name.toLowerCase() : "";
-                // Alt+F / Alt+D, never bare — type-to-filter claims printable keys.
-                if (name === "f" && onFavoriteToggle !== undefined) {
+                if (
+                  !key.ctrl &&
+                  (key.meta || key.option) &&
+                  name === "f" &&
+                  onFavoriteToggle !== undefined
+                ) {
                   // Empty id is the "(no matches)" filter sentinel — not a model.
                   if (itemId.length === 0) return false;
                   onFavoriteToggle(itemId);
                   return true;
                 }
-                if (name === "d" && onSetDefault !== undefined) {
-                  if (itemId.length === 0) return false;
+                if (
+                  onSetDefault !== undefined &&
+                  isSetDefaultShortcutKey(key)
+                ) {
+                  if (itemId.length === 0) return true;
                   onSetDefault(itemId);
                   return true;
                 }

src/tui/shell/palette.ts

@@ -168,6 +168,7 @@ export function handlePaletteFilterKey(
  * Glyphs some terminals emit for Option+A without setting meta/option.
  */
 const OPTION_A_COMPOSED_CHARS = new Set(["å", "Å"]);
+const OPTION_D_COMPOSED_CHARS = new Set(["∂"]);
 
 /**
  * True when a key event is the model-picker Alt+A add-provider chord.
@@ -183,6 +184,20 @@ export function isAddProviderShortcutKey(key: KeyEvent): boolean {
   return false;
 }
 
+/**
+ * True when a key event is the model-picker Alt+D set-default chord.
+ * Terminals may deliver Option+D as ∂ without meta/option.
+ */
+export function isSetDefaultShortcutKey(key: KeyEvent): boolean {
+  if (key.ctrl) return false;
+  const name = typeof key.name === "string" ? key.name : "";
+  const seq = typeof key.sequence === "string" ? key.sequence : "";
+  if ((key.meta || key.option) && name.toLowerCase() === "d") return true;
+  if (OPTION_D_COMPOSED_CHARS.has(name) || OPTION_D_COMPOSED_CHARS.has(seq))
+    return true;
+  return false;
+}
+
 /**
  * Keys a type-to-filter list overlay claims while open, so the `>` row
  * narrows as you type. Mirrors the palette filter, but updates the open
@@ -206,6 +221,16 @@ export function handleListFilterKey(shell: AppShell, key: KeyEvent): boolean {
     return false;
   }
 
+  // setDefaultHint similarly gates the composed Option+D (∂) bypass. Outside
+  // this model-picker action context, ∂ remains ordinary filter text.
+  if (
+    bag?.primaryBindings.setDefaultHint === true &&
+    shell.overlayKind === "model_picker" &&
+    isSetDefaultShortcutKey(key)
+  ) {
+    return false;
+  }
+
   if (key.name === "backspace") {
     if (state.query.length === 0) return true;
     state.query = state.query.slice(0, -1);