Fix

.babelrc

@@ -0,0 +1,7 @@
+{
+  "env": {
+    "test": {
+      "plugins": ["istanbul"]
+    }
+  }
+}

cypress.config.ts

@@ -2,6 +2,7 @@
 import installCoverageTask from "@cypress/code-coverage/task";
 import { defineConfig } from "cypress";
 import { devServer } from "cypress-rspack-dev-server";
+import { merge } from "webpack-merge";
 
 export default defineConfig({
   viewportWidth: 1280,
@@ -25,12 +26,11 @@ export default defineConfig({
       return devServer({
         ...devServerConfig,
         framework: "react",
-        rspackConfig: {
-          ...require("./rspack.config").default,
+        rspackConfig: merge(require("./rspack.config").default, {
           experiments: {
             lazyCompilation: !devServerConfig.cypressConfig.isTextTerminal,
           },
-        },
+        }),
       });
     },
     specPattern: "packages/**/src/**/*.cy.{js,ts,jsx,tsx}",

rspack.config.ts

@@ -1,5 +1,6 @@
 import path from "node:path";
 import { defineConfig } from "@rspack/cli";
+import { version as reactVersion } from "react";
 
 const prod = true;
 
@@ -15,6 +16,10 @@ export default defineConfig({
         test: /\.css$/,
         use: ["style-loader", "css-loader", "postcss-loader"],
       },
+      {
+        test: /packages\/.*\/src\/.*\.[tj]sx?$/,
+        use: ["babel-loader"],
+      },
       {
         test: /\.(j|t)s$/,
         exclude: [/[\\/]node_modules[\\/]/],
@@ -63,6 +68,11 @@ export default defineConfig({
       configFile: path.resolve(__dirname, "./tsconfig.json"),
       references: "auto",
     },
+    alias: {
+      "cypress/react18": reactVersion.startsWith("18")
+        ? "cypress/react18"
+        : "cypress/react",
+    },
     extensions: ["...", ".ts", ".tsx", ".js", ".jsx", ".css"],
   },
 });