1 files changed, 49 insertions, 0 deletions
diff --git a/src/adapters/portal.test.ts b/src/adapters/portal.test.ts
new file mode 100644
index 0000000..a5624d5
--- /dev/null
+++ b/src/adapters/portal.test.ts
@@ -0,0 +1,49 @@
+import { afterEach, describe, expect, it } from "vitest";
+import { portal } from "./portal";
+
+describe("portal action", () => {
+  afterEach(() => {
+    // Strip any leftover teleported nodes between tests.
+    document.querySelectorAll("body > :not(script)").forEach((n) => {
+      if (n instanceof HTMLElement) n.remove();
+    });
+  });
+
+  it("teleports the node to document.body (escaping an ancestor with transform)", () => {
+    // Simulate the sidebar: a transformed ancestor establishes a containing
+    // block for `position: fixed`.
+    const ancestor = document.createElement("div");
+    ancestor.style.transform = "translateX(0)";
+    document.body.appendChild(ancestor);
+
+    const node = document.createElement("div");
+    node.setAttribute("data-testid", "modal");
+    ancestor.appendChild(node);
+    expect(node.parentNode).toBe(ancestor);
+
+    const action = portal(node);
+
+    // After the action, the node is a direct child of <body>, not the ancestor.
+    expect(node.parentNode).toBe(document.body);
+    expect(ancestor.contains(node)).toBe(false);
+
+    action.destroy();
+
+    // On destroy the node is removed from <body>.
+    expect(document.body.contains(node)).toBe(false);
+  });
+
+  it("is a no-op (does not throw) when document is unavailable (SSR guard)", () => {
+    const originalDocument = globalThis.document;
+    // @ts-expect-error — deliberately undefined to exercise the SSR guard.
+    globalThis.document = undefined;
+    try {
+      const stub = {} as HTMLElement;
+      const action = portal(stub);
+      // Must not throw, and returns a destroy that is safe to call.
+      action.destroy();
+    } finally {
+      globalThis.document = originalDocument;
+    }
+  });
+});