test(FN-4121): complete Step 2 — cover layout preference resolver behavior

Fusion-Task-Id: FN-4121
Fusion-Task-Lineage: aa8b8ab7-c250-4ce5-b42e-7b7a2ba920b1

packages/dashboard/app/components/__tests__/agentsOrgChartLayout.test.ts

@@ -1,6 +1,10 @@
 import { describe, expect, it } from "vitest";
 import type { OrgTreeNode } from "../../api";
-import { estimateOrgChartWidth, resolveOrgChartLayoutMode } from "../agentsOrgChartLayout";
+import {
+  estimateOrgChartWidth,
+  isOrgChartLayoutPreference,
+  resolveOrgChartLayoutMode,
+} from "../agentsOrgChartLayout";
 
 function makeNode(id: string, children: OrgTreeNode[] = []): OrgTreeNode {
   return {
@@ -40,4 +44,49 @@ describe("agentsOrgChartLayout", () => {
     expect(resolveOrgChartLayoutMode({ tree, availableWidth: 0 })).toBe("horizontal");
     expect(resolveOrgChartLayoutMode({ tree, availableWidth: 120 })).toBe("horizontal");
   });
+
+  it("forces horizontal when preference is horizontal", () => {
+    const tree = [
+      makeNode("root", [
+        makeNode("a", [makeNode("a1"), makeNode("a2")]),
+        makeNode("b", [makeNode("b1"), makeNode("b2")]),
+      ]),
+      makeNode("root-2", [makeNode("c"), makeNode("d")]),
+    ];
+    expect(resolveOrgChartLayoutMode({ tree, availableWidth: 400, preference: "horizontal" })).toBe("horizontal");
+  });
+
+  it("forces vertical when preference is vertical", () => {
+    const tree = [makeNode("root", [makeNode("child")])];
+    const width = estimateOrgChartWidth(tree);
+    expect(resolveOrgChartLayoutMode({ tree, availableWidth: width + 1, preference: "vertical" })).toBe("vertical");
+  });
+
+  it("treats auto preference the same as omission", () => {
+    const tree = [
+      makeNode("root", [
+        makeNode("a", [makeNode("a1"), makeNode("a2")]),
+        makeNode("b", [makeNode("b1"), makeNode("b2")]),
+      ]),
+      makeNode("root-2", [makeNode("c"), makeNode("d")]),
+    ];
+
+    expect(resolveOrgChartLayoutMode({ tree, availableWidth: 400, preference: "auto" })).toBe(
+      resolveOrgChartLayoutMode({ tree, availableWidth: 400 }),
+    );
+  });
+});
+
+describe("isOrgChartLayoutPreference", () => {
+  it("accepts valid preference values", () => {
+    expect(isOrgChartLayoutPreference("auto")).toBe(true);
+    expect(isOrgChartLayoutPreference("horizontal")).toBe(true);
+    expect(isOrgChartLayoutPreference("vertical")).toBe(true);
+  });
+
+  it("rejects invalid preference values", () => {
+    expect(isOrgChartLayoutPreference(null)).toBe(false);
+    expect(isOrgChartLayoutPreference("")).toBe(false);
+    expect(isOrgChartLayoutPreference("auto-fit")).toBe(false);
+  });
 });