No tests found in spec file

[d3caf]

Reproduction repo: https://github.com/andrew-anguiano/reproductions/tree/main/cypress-component-testing-16784

I'm trying to set up Cypress in a new React+TS project and use the new component testing feature. I followed the setup process in the docs, but when I run yarn run cypress open-ct and select a component to test, I just see "Your tests are loading..." and nothing ever happens. No tests are shown in the pane. I'm not seeing any errors being output either.

Here is my webpack config:

const webpack = require('webpack');
const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
// const LodashModuleReplacementPlugin = require('lodash-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const ReactRefreshWebpackPlugin = require('@pmmmwh/react-refresh-webpack-plugin');
const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin');

const isDevelopment = process.env.NODE_ENV !== 'production';

const config = {
  mode: isDevelopment ? 'development' : 'production',
  devtool: isDevelopment ? 'eval-source-map' : 'none',
  entry: './src/index.tsx',
  target: isDevelopment ? 'web' : 'browserslist',
  devServer: {
    contentBase: path.join(__dirname, 'dist'),
    historyApiFallback: true,
    publicPath: '/',
    hot: true,
  },
  output: {
    path: path.resolve(__dirname, '../../priv/static/js'),
    filename: 'app.js',
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        use: 'babel-loader',
        exclude: /node_modules/,
      },
      {
        test: /\.ts(x)?$/,
        exclude: /node_modules/,
        use: [
          {
            loader: 'babel-loader',
            options: {
              plugins: [isDevelopment && require.resolve('react-refresh/babel')].filter(Boolean),
            },
          },
        ],
      },
      {
        test: /\.js$/,
        enforce: 'pre',
        use: ['source-map-loader'],
      },
      {
        test: /\.css$/,
        use: [
          'style-loader',
          {
            loader: 'css-loader',
            options: {
              importLoaders: 1,
              modules: true,
            },
          },
        ],
      },
      {
        test: /\.module.scss$/,
        use: [
          isDevelopment ? 'style-loader' : MiniCssExtractPlugin.loader,
          {
            loader: 'css-loader',
            options: {
              modules: true,
              sourceMap: isDevelopment,
            },
          },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: isDevelopment,
              sassOptions: {
                includePaths: ['node_modules/gravity/dist/css'],
              },
            },
          },
        ],
      },
      {
        test: /\.scss$/,
        exclude: /\.module.scss$/,
        use: [
          isDevelopment ? 'style-loader' : MiniCssExtractPlugin.loader,
          {
            loader: 'css-loader',
            options: {
              sourceMap: isDevelopment,
            },
          },
          {
            loader: 'sass-loader',
            options: {
              sourceMap: isDevelopment,
            },
          },
        ],
      },
      {
        oneOf: [
          {
            resourceQuery: /raw/,
            type: 'asset/source',
          },
          {
            test: /\.svg$/,
            use: 'asset/source',
          },
        ],
      },
      {
        test: /\.png$/,
        type: 'asset',
      },
      {
        test: /\.(woff|woff2)$/,
        type: 'asset/inline',
      },
    ],
  },
  resolve: {
    extensions: ['.js', '.jsx', '.tsx', '.ts', '.scss'],
    alias: {
      '@': path.resolve(__dirname, 'src'),
    },
  },
  plugins: [
    // new LodashModuleReplacementPlugin(),
    new MiniCssExtractPlugin({
      filename: isDevelopment ? '../css/[name].css' : '../css/[name].[hash].css',
      chunkFilename: isDevelopment ? '../css/[id].css' : '../css/[id].[hash].css',
    }),
    new ForkTsCheckerWebpackPlugin({
      eslint: {
        files: './src/**/*.{ts,tsx,js,jsx}',
      },
    }),
    new webpack.DefinePlugin({
      'process.env.NAME': JSON.stringify(require('./package.json').name),
      'process.env.VERSION': JSON.stringify(require('./package.json').version),
      IS_DEVELOPMENT: isDevelopment,
      ENDPOINTS: {
        // removed
      },
    }),
    new HtmlWebpackPlugin({
      template: './public/index.html',
      publicPath: '/',
    }),
    isDevelopment && new ReactRefreshWebpackPlugin(),
  ].filter(Boolean),
};

module.exports = config;

and my plugins/index.js file in the cypress folder:

module.exports = (on, config) => {
  // `on` is used to hook into various events Cypress emits
  // `config` is the resolved Cypress config
  if (config.testingType === 'component') {
    const { startDevServer } = require('@cypress/webpack-dev-server');
    const webpackConfig = require('../../webpack.config.ts');

    on('dev-server:start', (options) => startDevServer({ options, webpackConfig }));
  }
};

Thanks for any help!

Update
Investigating further: it appears that the test file is never loaded... I'll dig further.

Update 2
It seems to be an issue with my webpack config. Now it's loading the test files, but unable to find any tests in them...