A test renderer for React hooks

packages/react/package.json

@@ -83,6 +83,7 @@
         "jest-runner-prettier": "^1.0.0",
         "prettier": "^3.1",
         "react": "^18",
+        "react-error-boundary": "^4.0.12",
         "react-test-renderer": "^18",
         "test-config": "workspace:*",
         "tsconfig": "workspace:*",

packages/react/src/test-renderer.tsx

@@ -0,0 +1,70 @@
+import React from 'react';
+import { ErrorBoundary } from 'react-error-boundary';
+import { act, create, ReactTestRenderer } from 'react-test-renderer';
+
+type Result<T> =
+    | {
+          __type: 'error';
+          current: Error;
+          reset: () => void;
+      }
+    | {
+          __type: 'result';
+          current?: T;
+      };
+
+type TestComponentProps<THookReturn> = {
+    executor(): THookReturn;
+    resultRef: Result<THookReturn>;
+};
+
+function TestComponentHookRenderer<THookFn extends (...args: never) => unknown>({
+    executor,
+    resultRef,
+}: TestComponentProps<ReturnType<THookFn>>) {
+    resultRef.current = executor();
+    return null;
+}
+
+function TestComponent<THookFn extends (...args: never) => unknown>({
+    executor,
+    resultRef,
+}: TestComponentProps<ReturnType<THookFn>>) {
+    return (
+        <ErrorBoundary
+            fallbackRender={({ error, resetErrorBoundary }) => {
+                resultRef.__type = 'error';
+                resultRef.current = error;
+                (resultRef as Extract<typeof resultRef, { __type: 'error' }>).reset = resetErrorBoundary;
+                return null;
+            }}
+            onReset={() => {
+                resultRef.__type = 'result';
+                delete resultRef.current;
+                // eslint-disable-next-line @typescript-eslint/no-explicit-any
+                delete (resultRef as any).reset;
+            }}
+        >
+            <TestComponentHookRenderer executor={executor} resultRef={resultRef} />
+        </ErrorBoundary>
+    );
+}
+
+export function renderHook<THookReturn>(executor: () => THookReturn): {
+    rerenderHook(nextExecutor: () => THookReturn): void;
+    result: Readonly<Result<THookReturn>>;
+} {
+    const result = { __type: 'result' } as Result<THookReturn>;
+    let testRenderer: ReactTestRenderer;
+    act(() => {
+        testRenderer = create(<TestComponent executor={executor} resultRef={result} />);
+    });
+    return {
+        rerenderHook(nextExecutor) {
+            act(() => {
+                testRenderer.update(<TestComponent executor={nextExecutor} resultRef={result} />);
+            });
+        },
+        result,
+    };
+}