Refine mine inbox shortcut behavior

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/lib/inbox.test.ts

@@ -6,6 +6,7 @@ import {
   computeInboxBadgeData,
   getApprovalsForTab,
   getInboxWorkItems,
+  getInboxKeyboardSelectionIndex,
   getRecentTouchedIssues,
   getUnreadTouchedIssues,
   isMineInboxTab,
@@ -411,9 +412,15 @@ describe("inbox helpers", () => {
   });
 
   it("anchors Mine selection to the first available inbox row", () => {
-    expect(resolveInboxSelectionIndex(-1, 3, true)).toBe(0);
-    expect(resolveInboxSelectionIndex(-1, 3, false)).toBe(-1);
-    expect(resolveInboxSelectionIndex(5, 3, true)).toBe(2);
-    expect(resolveInboxSelectionIndex(1, 0, true)).toBe(-1);
+    expect(resolveInboxSelectionIndex(-1, 3)).toBe(-1);
+    expect(resolveInboxSelectionIndex(5, 3)).toBe(2);
+    expect(resolveInboxSelectionIndex(1, 0)).toBe(-1);
+  });
+
+  it("selects the first row only after keyboard navigation starts", () => {
+    expect(getInboxKeyboardSelectionIndex(-1, 3, "next")).toBe(0);
+    expect(getInboxKeyboardSelectionIndex(-1, 3, "previous")).toBe(0);
+    expect(getInboxKeyboardSelectionIndex(0, 3, "next")).toBe(1);
+    expect(getInboxKeyboardSelectionIndex(0, 3, "previous")).toBe(0);
   });
 });

ui/src/lib/inbox.ts

@@ -105,13 +105,24 @@ export function isMineInboxTab(tab: InboxTab): boolean {
 export function resolveInboxSelectionIndex(
   previousIndex: number,
   itemCount: number,
-  canSelectItems: boolean,
 ): number {
   if (itemCount === 0) return -1;
-  if (previousIndex < 0) return canSelectItems ? 0 : -1;
+  if (previousIndex < 0) return -1;
   return Math.min(previousIndex, itemCount - 1);
 }
 
+export function getInboxKeyboardSelectionIndex(
+  previousIndex: number,
+  itemCount: number,
+  direction: "next" | "previous",
+): number {
+  if (itemCount === 0) return -1;
+  if (previousIndex < 0) return 0;
+  return direction === "next"
+    ? Math.min(previousIndex + 1, itemCount - 1)
+    : Math.max(previousIndex - 1, 0);
+}
+
 export function getLatestFailedRunsByAgent(runs: HeartbeatRun[]): HeartbeatRun[] {
   const sorted = [...runs].sort(
     (a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime(),