feat(ui): add expandable microinteractions

- Add visible open and close motion to collapsible content
- Animate tree row, chevron, and selection feedback
- Cover expandable motion behavior with focused unit tests

ui/components/shadcn/collapsible.test.tsx

@@ -0,0 +1,59 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it } from "vitest";
+
+import {
+  Collapsible,
+  CollapsibleContent,
+  CollapsibleTrigger,
+} from "./collapsible";
+
+describe("Collapsible", () => {
+  it("uses an intentional open and close motion contract", () => {
+    // Given
+    render(
+      <Collapsible open>
+        <CollapsibleTrigger>Toggle details</CollapsibleTrigger>
+        <CollapsibleContent>Expandable content</CollapsibleContent>
+      </Collapsible>,
+    );
+
+    // When
+    const content = screen.getByText("Expandable content");
+
+    // Then
+    expect(content).toHaveAttribute("data-slot", "collapsible-content");
+    expect(content).toHaveClass(
+      "overflow-hidden",
+      "duration-200",
+      "ease-out",
+      "data-[state=open]:animate-in",
+      "data-[state=open]:fade-in-0",
+      "data-[state=open]:slide-in-from-top-1",
+      "data-[state=closed]:animate-out",
+      "data-[state=closed]:fade-out-0",
+      "data-[state=closed]:slide-out-to-top-1",
+      "data-[state=closed]:duration-150",
+      "data-[state=closed]:ease-in",
+    );
+  });
+
+  it("removes transform-heavy motion for reduced-motion users", () => {
+    // Given
+    render(
+      <Collapsible open>
+        <CollapsibleTrigger>Toggle details</CollapsibleTrigger>
+        <CollapsibleContent>Expandable content</CollapsibleContent>
+      </Collapsible>,
+    );
+
+    // When
+    const content = screen.getByText("Expandable content");
+
+    // Then
+    expect(content).toHaveClass(
+      "motion-reduce:animate-none",
+      "motion-reduce:transform-none",
+      "motion-reduce:transition-none",
+    );
+  });
+});

ui/components/shadcn/collapsible.tsx

@@ -2,6 +2,8 @@
 
 import * as CollapsiblePrimitive from "@radix-ui/react-collapsible";
 
+import { cn } from "@/lib/utils";
+
 function Collapsible({
   ...props
 }: React.ComponentProps<typeof CollapsiblePrimitive.Root>) {
@@ -20,11 +22,20 @@ function CollapsibleTrigger({
 }
 
 function CollapsibleContent({
+  className,
   ...props
 }: React.ComponentProps<typeof CollapsiblePrimitive.CollapsibleContent>) {
   return (
     <CollapsiblePrimitive.CollapsibleContent
       data-slot="collapsible-content"
+      className={cn(
+        "overflow-hidden duration-200 ease-out",
+        "data-[state=open]:animate-in data-[state=open]:fade-in-0 data-[state=open]:slide-in-from-top-1",
+        "data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=closed]:slide-out-to-top-1",
+        "data-[state=closed]:duration-150 data-[state=closed]:ease-in",
+        "motion-reduce:transform-none motion-reduce:animate-none motion-reduce:transition-none",
+        className,
+      )}
       {...props}
     />
   );

ui/components/shadcn/tree-view/tree-leaf.tsx

@@ -58,7 +58,9 @@ export function TreeLeaf({
       className={cn(
         "flex items-center gap-2 rounded-md px-2 py-1.5",
         "hover:bg-prowler-white/5 cursor-pointer",
+        "transition-[background-color,box-shadow,color] duration-150 ease-out motion-reduce:transition-none",
         "focus-visible:ring-border-input-primary-press focus-visible:ring-2 focus-visible:outline-none",
+        isSelected && "bg-prowler-white/5",
         item.disabled && "cursor-not-allowed opacity-50",
         item.className,
       )}

ui/components/shadcn/tree-view/tree-node.tsx

@@ -96,7 +96,9 @@ export function TreeNode({
         className={cn(
           "flex items-center gap-2 rounded-md px-2 py-1.5",
           "hover:bg-prowler-white/5 cursor-pointer",
+          "transition-[background-color,box-shadow,color] duration-150 ease-out motion-reduce:transition-none",
           "focus-visible:ring-border-input-primary-press focus-visible:ring-2 focus-visible:outline-none",
+          isSelected && "bg-prowler-white/5",
           item.disabled && "cursor-not-allowed opacity-50",
           item.className,
         )}
@@ -110,7 +112,7 @@ export function TreeNode({
         onKeyDown={handleKeyDown}
       >
         <button
-          className="hover:bg-prowler-white/10 shrink-0 rounded p-0.5"
+          className="hover:bg-prowler-white/10 shrink-0 rounded p-0.5 transition-colors duration-150 ease-out motion-reduce:transition-none"
           aria-label={isExpanded ? "Collapse" : "Expand"}
           onClick={(e) => {
             e.stopPropagation();
@@ -123,7 +125,7 @@ export function TreeNode({
           ) : (
             <ChevronRightIcon
               className={cn(
-                "h-4 w-4 transition-transform duration-200",
+                "h-4 w-4 transition-transform duration-200 ease-out motion-reduce:transition-none",
                 isExpanded && "rotate-90",
               )}
             />

ui/components/shadcn/tree-view/tree-view.test.tsx

@@ -0,0 +1,76 @@
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+
+import { TreeView } from "./tree-view";
+
+const treeData = [
+  {
+    id: "org-1",
+    name: "Organization",
+    children: [
+      { id: "account-1", name: "Production" },
+      { id: "account-2", name: "Development" },
+    ],
+  },
+];
+
+describe("TreeView", () => {
+  it("animates node affordances and expanded content", () => {
+    // Given
+    render(<TreeView data={treeData} expandedIds={["org-1"]} showCheckboxes />);
+
+    // When
+    const node = screen.getByRole("treeitem", { name: /organization/i });
+    const expandButton = screen.getByRole("button", { name: /collapse/i });
+    const chevron = expandButton.querySelector("svg");
+    const group = screen.getByRole("group");
+
+    // Then
+    expect(node).toHaveClass(
+      "transition-[background-color,box-shadow,color]",
+      "duration-150",
+      "ease-out",
+      "motion-reduce:transition-none",
+    );
+    expect(expandButton).toHaveClass(
+      "transition-colors",
+      "duration-150",
+      "ease-out",
+      "motion-reduce:transition-none",
+    );
+    expect(chevron).toHaveClass(
+      "transition-transform",
+      "duration-200",
+      "ease-out",
+      "motion-reduce:transition-none",
+      "rotate-90",
+    );
+    expect(group).toHaveClass("overflow-hidden");
+  });
+
+  it("animates selected leaf row feedback", () => {
+    // Given
+    render(
+      <TreeView
+        data={treeData}
+        expandedIds={["org-1"]}
+        selectedIds={["account-1"]}
+        onSelectionChange={vi.fn()}
+        showCheckboxes
+      />,
+    );
+
+    // When
+    const selectedLeaf = screen.getByRole("treeitem", { name: /production/i });
+
+    // Then
+    expect(selectedLeaf).toHaveAttribute("aria-selected", "true");
+    expect(selectedLeaf).toHaveClass(
+      "bg-prowler-white/5",
+      "transition-[background-color,box-shadow,color]",
+      "duration-150",
+      "ease-out",
+      "motion-reduce:transition-none",
+    );
+  });
+});