refactor: fix test

Author: mdjastrzebski

src/__tests__/render.test.tsx

@@ -164,8 +164,8 @@ test('returns host root', () => {
   render(<View testID="inner" />);
 
   expect(screen.root).toBeDefined();
-  expect(screen.root.type).toBe('View');
-  expect(screen.root.props.testID).toBe('inner');
+  expect(screen.root?.type).toBe('View');
+  expect(screen.root?.props.testID).toBe('inner');
 });
 
 test('returns container', () => {

src/helpers/host-component-names.tsx

@@ -45,12 +45,12 @@ function detectHostComponentNames(): HostComponentNames {
       );
     });
     return {
-      text: getByTestId(renderer.root, 'text').type as string,
-      textInput: getByTestId(renderer.root, 'textInput').type as string,
-      image: getByTestId(renderer.root, 'image').type as string,
-      switch: getByTestId(renderer.root, 'switch').type as string,
-      scrollView: getByTestId(renderer.root, 'scrollView').type as string,
-      modal: getByTestId(renderer.root, 'modal').type as string,
+      text: getByTestId(renderer.container, 'text').type as string,
+      textInput: getByTestId(renderer.container, 'textInput').type as string,
+      image: getByTestId(renderer.container, 'image').type as string,
+      switch: getByTestId(renderer.container, 'switch').type as string,
+      scrollView: getByTestId(renderer.container, 'scrollView').type as string,
+      modal: getByTestId(renderer.container, 'modal').type as string,
     };
   } catch (error) {
     const errorMessage =

src/render.tsx

@@ -69,7 +69,7 @@ function buildRenderResult(renderer: Renderer, wrap: (element: React.ReactElemen
     toJSON: renderer.toJSON,
     debug: debug(renderer),
     container: renderer.container,
-    get root(): HostElement {
+    get root(): HostElement | null {
       return renderer.root;
     },
   };

src/renderer/renderer.ts

@@ -11,8 +11,8 @@ export type RendererOptions = {
 export type Renderer = {
   render: (element: ReactElement) => void;
   unmount: () => void;
-  root: HostElement;
   container: HostElement;
+  root: HostElement | null;
   toJSON: () => JsonNode | JsonNode[] | null;
 };
 
@@ -79,11 +79,15 @@ export function createRenderer(options?: RendererOptions): Renderer {
     render,
     unmount,
     toJSON,
-    get root(): HostElement {
-      if (containerFiber == null || container == null || container.children.length === 0) {
+    get root(): HostElement | null {
+      if (containerFiber == null || container == null) {
         throw new Error("Can't access .root on unmounted test renderer");
       }
 
+      if (container.children.length === 0) {
+        return null;
+      }
+
       const root = HostElement.fromInstance(container.children[0]);
       if (typeof root === 'string') {
         throw new Error('Cannot render string as root element');

src/screen.ts

@@ -18,7 +18,7 @@ interface Screen extends RenderResult {
 
 const defaultScreen: Screen = {
   isDetached: true,
-  get root(): HostElement {
+  get root(): HostElement | null {
     throw new Error(SCREEN_ERROR);
   },
   get container(): HostElement {