1 files changed, 67 insertions, 0 deletions
diff --git a/src/features/surface-host/logic/todo.test.ts b/src/features/surface-host/logic/todo.test.ts
new file mode 100644
index 0000000..66ff036
--- /dev/null
+++ b/src/features/surface-host/logic/todo.test.ts
@@ -0,0 +1,67 @@
+import { describe, expect, it } from "vitest";
+import { parseTodoPayload, type TodoItem } from "./todo";
+
+const item = (content: string, status: TodoItem["status"] = "pending"): TodoItem => ({
+  content,
+  status,
+});
+
+describe("parseTodoPayload", () => {
+  it("parses a well-formed payload with items", () => {
+    const data = parseTodoPayload({
+      todos: [
+        item("Write tests", "in_progress"),
+        item("Ship it", "pending"),
+        item("Read docs", "completed"),
+      ],
+    });
+    expect(data).toEqual({
+      todos: [
+        item("Write tests", "in_progress"),
+        item("Ship it", "pending"),
+        item("Read docs", "completed"),
+      ],
+    });
+  });
+
+  it("parses an empty-todos payload", () => {
+    expect(parseTodoPayload({ todos: [] })).toEqual({ todos: [] });
+  });
+
+  it("preserves item order", () => {
+    const data = parseTodoPayload({ todos: [item("a"), item("b"), item("c")] });
+    expect(data?.todos.map((t) => t.content)).toEqual(["a", "b", "c"]);
+  });
+
+  it("accepts all four status values", () => {
+    const data = parseTodoPayload({
+      todos: [
+        item("p", "pending"),
+        item("i", "in_progress"),
+        item("c", "completed"),
+        item("x", "cancelled"),
+      ],
+    });
+    expect(data?.todos.map((t) => t.status)).toEqual([
+      "pending",
+      "in_progress",
+      "completed",
+      "cancelled",
+    ]);
+  });
+
+  it.each([
+    ["null", null],
+    ["a number", 7],
+    ["a string", "nope"],
+    ["missing todos key", { foo: [] }],
+    ["todos not an array", { todos: "x" }],
+    ["entry not an object", { todos: ["x"] }],
+    ["entry missing content", { todos: [{ status: "pending" }] }],
+    ["entry with non-string content", { todos: [{ content: 1, status: "pending" }] }],
+    ["entry missing status", { todos: [{ content: "x" }] }],
+    ["entry with invalid status", { todos: [item("x", "done" as never)] }],
+  ])("returns null for invalid payload: %s", (_label, payload) => {
+    expect(parseTodoPayload(payload)).toBeNull();
+  });
+});