med-plan-assistant/docs/README.dev-notes.md

Development Notes

Current Tech Stack (2025-11-26)

• React 19.1.1 with TypeScript 5.9.3
• shadcn/ui component library (Radix UI + Tailwind)
• Tailwind CSS 3.4.18 for styling
• Recharts 3.3.0 for data visualization
• Vite 5 as build tool

Version Management

The project uses a hybrid versioning approach:

• Semver (e.g., 0.2.1) in package.json for npm ecosystem compatibility
• Git hash (e.g., +a3f2b9c) automatically appended at build time
• Displayed version in UI footer: 0.2.1+a3f2b9c (or 0.2.1+a3f2b9c-dirty if uncommitted changes)

Version Scripts

# Bump version manually (updates package.json)
npm run version:patch  # 0.2.1 → 0.2.2 (bug fixes)
npm run version:minor  # 0.2.1 → 0.3.0 (new features)
npm run version:major  # 0.2.1 → 1.0.0 (breaking changes)

# Generate version.json with git info (runs automatically on build)
npm run prebuild

# Build for production (automatically generates version)
npm run build

How It Works

1. Manual semver bump: Run npm run version:patch|minor|major when you want to increment the version
2. Automatic git info: On build, scripts/generate-version.js creates src/version.json with:
   • version: Semver + git hash (e.g., 0.2.1+a3f2b9c)
   • semver: Just the semver (e.g., 0.2.1)
   • commit: Git commit hash (e.g., a3f2b9c)
   • branch: Current git branch
   • buildDate: ISO timestamp
   • gitDate: Commit date
3. Fallback handling: If version.json is missing (fresh clone before first build), src/constants/defaults.ts generates a fallback version from package.json

Version Display

The version is displayed in the UI footer (bottom right) next to the GitHub repository link. The format is:

• 0.2.1+a3f2b9c (clean working directory)
• 0.2.1+a3f2b9c-dirty (uncommitted changes present)
• 0.2.1-dev (fallback when version.json is missing)

Files

• scripts/generate-version.js - Generates version.json from git + package.json
• scripts/bump-version.js - Manually bumps semver in package.json
• src/version.json - Auto-generated, ignored by git
• src/version.json.template - Fallback template (committed to repo)
• src/constants/defaults.ts - Exports APP_VERSION and BUILD_INFO

Initial Setup (Fresh Clone)

# Install all dependencies
npm install

# Run development server (Vite on port 3000)
npm start

# Build for production
npm run build

# Optionally preview the production build
npm run preview

2026-01-07 Build Tool Migration

We migrated from Create React App to Vite to resolve conflicting optional peer dependencies around typescript (CRA expected TS ^3.2 || ^4 while several libraries prefer TS ^5). Vite supports modern TypeScript and avoids those conflicts, making new workspace setups straightforward. It is also much faster in dev mode.

shadcn/ui Setup (Already Done)

The project was set up with shadcn/ui components. If you need to add more components:

# Add new shadcn/ui components
npx shadcn@latest add [component-name]

# Example:
npx shadcn@latest add dialog

TypeScript Configuration

TypeScript is configured with:

• Strict mode enabled
• Path aliases: @/* → ./src/*
• Target: ES5
• Module: ESNext
• JSX: react-jsx

Tailwind CSS Configuration

Content paths in tailwind.config.js:

module.exports = {
  content: [
    "./src/**/*.{js,jsx,ts,tsx}",
  ],
  theme: {
    extend: {
      colors: {
        // HSL-based color system for shadcn/ui
      },
    },
  },
  plugins: [require("tailwindcss-animate")],
}

Global styles in ./src/styles/global.css:

@tailwind base;
@tailwind components;
@tailwind utilities;

@layer base {
  :root {
    --background: 0 0% 98%;
    --foreground: 222 47% 11%;
    /* ... more CSS variables for shadcn/ui theme */
  }
}

WSL Networking Issues

Please be aware that the issues and potential solutions in this section were relevant when using Create React App's webpack dev server. They may still apply to Vite in some cases, but Vite generally handles WSL2 networking better. The documentation was changed to reflect Vite usage (see earlier revisions), but never verified in all details.

If access to http://localhost:3000 does not work from Windows host when running the Vite dev server in WSL, look at the following troubleshooting steps.

Note that not all steps may be necessary, depending on your specific WSL and Windows setup.

For Vite: The HOST=0.0.0.0 binding is configured in vite.config.ts with server.host: true. The start:wsl2 script also sets the environment variable as a fallback.

In my case the npm start terminal output shows:

  Local:            http://localhost:3000
  On Your Network:  http://172.20.39.187:3000

WSL Networking Modes

Check and potentially change the network mode of WSL.

Option 1: NAT Networking Mode (Default)

This is the default mode used if Option 2 is not specifically set. Unless the settings described in Option 2 are applied, this mode is active.

Option 2: Mirrored Networking Mode (Windows 11 22H2+)

In %USERPROFILE%\.wslconfig add:

[wsl2]
networkingMode=mirrored

Then stop WSL and start it again so the changes take effect:

wsl --shutdown
wsl

Dev Server Host Binding

Vite automatically binds to all interfaces when server.host: true is set in vite.config.ts (already configured).

For WSL2 environments, use the dedicated script:

npm run start:wsl2

This sets HOST=0.0.0.0 explicitly as an environment variable for additional compatibility.

Port Forwarding

If you want to access the Vite dev server via http://localhost:3000 on Windows host, you need to set up port forwarding from Windows localhost to the WSL IP address.

First get the WSL IP address by running the following command in WSL:

hostname -I

# Or from Windows Command Prompt / PowerShell:
wsl hostname -I

Then use the WSL IP address (in my case 172.20.39.187) in the following command to set up permanent port forwarding.

# Add port forwarding rule
netsh interface portproxy add v4tov4 listenport=3000 listenaddress=127.0.0.1 connectport=3000 connectaddress=172.20.39.187

# Just in case you need to delete the rule later, use:
#netsh interface portproxy delete v4tov4 listenport=3000 listenaddress=127.0.0.1

You should now be able to access the Vite dev server via http://localhost:3000 on Windows host, instead of having to use the WSL IP address.

Open Firewall Ports

In case you have trouble with your Windows Firewall blocking access to the forwarded port, or you want to allow access from other devices on your network, you may need to open the port in the firewall.

Run the following PowerShell commands to open the necessary port (just an example, ensure that the settings fit your security requirements):

# Open port 3000 for inbound TCP traffic on WSL virtual network interface
New-NetFirewallRule -DisplayName "Allow WSL Inbound Port 3000" `
    -Direction Inbound -Action Allow -Protocol TCP -LocalPort 3000 `
    -InterfaceAlias "vEthernet (WSL (Hyper-V firewall))"

In case the above does not resolve your issues, just to rule out potential firewall issues, it is always an option to temporarily disable the firewall all together.

WARNING: IF YOU DO THIS, DO NOT FORGET TO RE-ENABLE THE FIREWALL AFTER TESTING!

VS Code Dev Container Port Forwarding

When running the Vite dev server in a VS Code dev container (WSL2 + Podman/Docker), VS Code automatically forwards ports from the container to the Windows host.

Vite HMR (Hot Module Replacement) automatically detects the correct WebSocket port from the page URL, so no special configuration is needed (unlike the old webpack dev server which required WDS_SOCKET_PORT=0).

You may encounter:

1. Port remapping: If port 3000 is busy on Windows, VS Code may forward to 3001 or another available port - this is normal and Vite will adapt automatically.

Dev Container vs Direct WSL2 Configuration Differences

In VS Code Dev Containers:

• HOST=0.0.0.0 is not needed - VS Code handles port forwarding from container's localhost
• File watching works reliably - Vite's HMR is fast and stable

In Direct WSL2 (no container):

• HOST=0.0.0.0 is recommended - to bind to WSL2's network interface for host access
• Manual port forwarding with netsh interface portproxy may be needed

Project Scripts:

The project includes separate scripts for different environments:

# In VS Code Dev Container (default, optimized)
npm start

# In direct WSL2 (without container)
npm run start:wsl2

Configured in package.json:

"scripts": {
  "start": "vite",
  "start:wsl2": "HOST=0.0.0.0 vite"
}

This way you don't need to modify scripts when switching between environments.

Configure Port Forwarding Behavior

In .devcontainer/devcontainer.json, you can configure port forwarding:

{
  "forwardPorts": [3000],
  "portsAttributes": {
    "3000": {
      "label": "Vite Dev Server",
      "onAutoForward": "notify"
    }
  }
}

Check Which Port is Actually Forwarded

In VS Code, check the PORTS tab (usually in the bottom panel) to see:

• Which container ports are forwarded
• Which Windows host ports they map to
• You can manually change the forwarded port by right-clicking the port entry

Note: If port 3000 is busy on Windows, VS Code may automatically forward to 3001 or another available port. This is normal - just use whatever port VS Code assigns in the PORTS tab.

Kill Stuck Dev Server

If you need to free port 3000 (e.g., stuck dev server process):

npm run kill

This script uses lsof to find and terminate any process using port 3000. Note: lsof must be installed in the container (already configured in Dockerfile).

Important: No Manual Port Proxy Needed

When using VS Code dev containers, you do not need netsh interface portproxy rules. VS Code handles all port forwarding automatically. Remove any existing rules:

netsh interface portproxy delete v4tov4 listenport=3000 listenaddress=127.0.0.1

Development Server

(Prevent) Auto Open in Browser

Vite does not automatically open the browser by default when the dev server starts. If you want to enable this behavior, add to vite.config.ts:

export default defineConfig({
  server: {
    open: true  // Opens browser automatically
  }
});

Hot Module Replacement (HMR)

Vite's HMR is significantly faster than webpack and works reliably in most environments including WSL2 and dev containers. File system watching is handled natively and typically doesn't require polling.

If you encounter issues with HMR not detecting changes (rare), you can configure polling in vite.config.ts:

export default defineConfig({
  server: {
    watch: {
      usePolling: true
    }
  }
});

Then the start script can remain as:

npm start

Webhint

Setup webhint in Project

Check local config:

# Install hint locally in the project
npm install hint --save-dev

# Optionally use the web-recommended config
#npm install @hint/configuration-web-recommended --save-dev
#npm create hintrc

# Or create .hintrc manually with a basic config
```sh
cat > .hintrc <<EOL
{
  "extends": ["web-recommended"]
}
EOL

Add webhint script to package.json:

"scripts": {
  "webhint": "hint"
}

Optionally install puppeteer if you want to run webhint with headless Chrome:

npm install puppeteer --save-dev

Run webhint

Ensure that the Vite development server is running when you run webhint against http://localhost:3000.

npm start

Run webhint:

npm run webhint -- http://localhost:3000

Open ./hint-report/http-localhost-3000.html in a browser to see the report.

VS Code: Problems with "Microsoft Edge Tools for VS Code" Extension

Error message:

Unable to start webhint. Ensure you are using the latest version of the hint package.

Solution:

Install webhint locally in the project as shown above, or update to the latest version:

npm install hint@latest --save-dev

In doubt check the global installation and remove it if necessary:

# Global config
npm list -g hint

# Uninstall global version if necessary
npm uninstall -g hint

External Resources

• https://github.com/webhintio/hint
• https://webhint.io/docs/user-guide/configuring-webhint/summary/