feat(app-next): app-next initial spike

This change introduces the new frontend system by adding a new app-next
package.  This new frontend can co-exist alongside the previous frontend
system and is enabled by setting the following environment variable:

```bash
export APP_CONFIG_app_packageName=app-next
```

before starting the RHDH backend.  An additional start:next script has
been added to the backend package, and it is also possible to use this
environment variable to select the new frontend when using the RHDH
container.

Signed-off-by: Stan Lewis <[email protected]>
Assisted-by: Cursor Desktop

Author: gashcrumb

.rhdh/docker/Dockerfile

@@ -73,6 +73,7 @@ COPY $EXTERNAL_SOURCE_NESTED/plugins/dynamic-plugins-info-backend/package.json .
 COPY $EXTERNAL_SOURCE_NESTED/packages/plugin-utils/package.json ./packages/plugin-utils/package.json
 COPY $EXTERNAL_SOURCE_NESTED/packages/backend/package.json ./packages/backend/package.json
 COPY $EXTERNAL_SOURCE_NESTED/packages/app/package.json ./packages/app/package.json
+COPY $EXTERNAL_SOURCE_NESTED/packages/app-next/package.json ./packages/app-next/package.json
 COPY $EXTERNAL_SOURCE_NESTED/package.json ./package.json
 # END COPY package.json files
 

docker/Dockerfile

@@ -72,6 +72,7 @@ COPY $EXTERNAL_SOURCE_NESTED/plugins/dynamic-plugins-info-backend/package.json .
 COPY $EXTERNAL_SOURCE_NESTED/packages/plugin-utils/package.json ./packages/plugin-utils/package.json
 COPY $EXTERNAL_SOURCE_NESTED/packages/backend/package.json ./packages/backend/package.json
 COPY $EXTERNAL_SOURCE_NESTED/packages/app/package.json ./packages/app/package.json
+COPY $EXTERNAL_SOURCE_NESTED/packages/app-next/package.json ./packages/app-next/package.json
 COPY $EXTERNAL_SOURCE_NESTED/package.json ./package.json
 # END COPY package.json files
 

packages/app-next/.eslintrc.js

@@ -0,0 +1,5 @@
+module.exports = require('@backstage/cli/config/eslint-factory')(__dirname, {
+    rules: {
+        '@backstage/no-top-level-material-ui-4-imports': 'error',
+    },
+});

packages/app-next/README.md

@@ -0,0 +1,42 @@
+# app-next
+
+## Overview
+
+This package contains the Red Hat Developer Hub (RHDH) frontend application built using Backstage's new frontend system architecture.  The `app-next` package leverages Backstage's new frontend system, which introduces a more modular and extensible architecture compared to the legacy frontend system. This new system is built around the concepts of extensions, plugins, and utility APIs, providing better composability and customization options.
+
+## Development
+
+### Primary Development Workflow
+
+The recommended way to run the new frontend system is using the `backend start:next` command:
+
+```bash
+# from the root of the repo
+yarn workspace backend start:next
+```
+
+### Standalone Development
+
+You can also run the frontend application independently for development:
+
+```bash
+# from the root of the repo
+yarn workspace app-next start
+```
+
+### Other Available Commands
+
+- `yarn build` - Build the application for production
+- `yarn test` - Run the test suite
+- `yarn lint` - Run linting checks
+- `yarn clean` - Clean build artifacts
+
+## Architecture
+
+This application is built using Backstage's [new frontend system](https://backstage.io/docs/frontend-system/architecture/index), which provides:
+
+- **Extension-based architecture**: Modular components that can be composed together
+- **Plugin system**: Reusable functionality packages
+- **Utility APIs**: Shared services and functionality
+- **Route management**: Dynamic routing system for plugin navigation
+- **Theming and customization**: Flexible styling and branding options

packages/app-next/package.json

@@ -0,0 +1,93 @@
+{
+  "name": "app-next",
+  "version": "0.0.23",
+  "private": true,
+  "bundled": true,
+  "backstage": {
+    "role": "frontend"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/redhat-developer/rhdh",
+    "directory": "packages/app-next"
+  },
+  "license": "Apache-2.0",
+  "files": [
+    "dist"
+  ],
+  "scripts": {
+    "build": "backstage-cli package build",
+    "clean": "backstage-cli package clean",
+    "lint": "backstage-cli package lint",
+    "start": "backstage-cli package start --config ../../app-config.yaml",
+    "test": "backstage-cli package test"
+  },
+  "browserslist": {
+    "production": [
+      ">0.2%",
+      "not dead",
+      "not op_mini all"
+    ],
+    "development": [
+      "last 1 chrome version",
+      "last 1 firefox version",
+      "last 1 safari version"
+    ]
+  },
+  "dependencies": {
+    "@backstage/app-defaults": "1.6.2",
+    "@backstage/catalog-model": "1.7.4",
+    "@backstage/cli": "0.32.1",
+    "@backstage/config": "1.3.2",
+    "@backstage/core-app-api": "1.17.0",
+    "@backstage/core-compat-api": "0.4.2",
+    "@backstage/core-components": "0.17.2",
+    "@backstage/core-plugin-api": "1.10.7",
+    "@backstage/frontend-app-api": "0.11.2",
+    "@backstage/frontend-defaults": "0.2.2",
+    "@backstage/frontend-dynamic-feature-loader": "0.1.0",
+    "@backstage/frontend-plugin-api": "0.10.2",
+    "@backstage/integration-react": "1.2.7",
+    "@backstage/plugin-app": "0.1.9",
+    "@backstage/plugin-app-visualizer": "0.1.19",
+    "@backstage/plugin-auth-react": "0.1.15",
+    "@backstage/plugin-catalog": "1.30.0",
+    "@backstage/plugin-catalog-common": "1.1.4",
+    "@backstage/plugin-catalog-graph": "0.4.19",
+    "@backstage/plugin-catalog-import": "0.13.0",
+    "@backstage/plugin-catalog-react": "1.18.0",
+    "@backstage/plugin-catalog-unprocessed-entities": "0.2.17",
+    "@backstage/plugin-home": "0.8.8",
+    "@backstage/plugin-permission-react": "0.4.34",
+    "@backstage/plugin-scaffolder": "1.31.0",
+    "@backstage/plugin-scaffolder-react": "1.16.0",
+    "@backstage/plugin-search": "1.4.26",
+    "@backstage/plugin-search-common": "1.2.18",
+    "@backstage/plugin-search-react": "1.9.0",
+    "@backstage/plugin-user-settings": "0.8.22",
+    "@backstage/theme": "0.6.6",
+    "@material-ui/core": "4.12.2",
+    "@material-ui/icons": "4.9.1",
+    "@material-ui/lab": "4.0.0-alpha.61",
+    "@octokit/rest": "19.0.3",
+    "history": "5.0.0",
+    "react": "18.3.1",
+    "react-dom": "18.3.1",
+    "react-router": "6.3.0",
+    "react-router-dom": "6.30.1",
+    "react-use": "17.6.0",
+    "zen-observable": "0.10.0"
+  },
+  "devDependencies": {
+    "@backstage/test-utils": "1.7.8",
+    "@testing-library/dom": "9.3.4",
+    "@testing-library/jest-dom": "6.6.3",
+    "@testing-library/react": "14.3.1",
+    "@testing-library/user-event": "14.6.1",
+    "@types/jquery": "3.3.34",
+    "@types/react": "18.3.23",
+    "@types/react-dom": "18.3.7",
+    "@types/zen-observable": "0.8.0",
+    "cross-env": "7.0.0"
+  }
+}