ci: add github pages

Author: OliverDudgeon

.github/workflows/deploy.yml

@@ -0,0 +1,66 @@
+name: Deploy to GitHub Pages
+
+on:
+  # Runs on pushes targeting the main branch
+  push:
+    branches: ["main"]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
+# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  # Build job
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 9.0.0
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: "pnpm"
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Build
+        run: pnpm run build
+
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: ./dist
+
+  # Deployment job
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

DEPLOYMENT.md

@@ -0,0 +1,80 @@
+# GitHub Pages Deployment Setup
+
+## What Was Added
+
+### 1. GitHub Actions Workflow (`.github/workflows/deploy.yml`)
+
+- Automatically builds and deploys to GitHub Pages on every push to `main`
+- Can also be triggered manually from the Actions tab
+- Uses pnpm for efficient dependency installation
+- Builds with `pnpm run build`
+- Deploys the `dist` folder to GitHub Pages
+
+### 2. Vite Configuration Update (`vite.config.ts`)
+
+- Added `base: "/observable-plot-scatter-poc/"` for correct asset paths on GitHub Pages
+- This ensures all JavaScript, CSS, and other assets load correctly from the subdirectory
+
+### 3. Jekyll Bypass (`public/.nojekyll`)
+
+- Empty file that tells GitHub Pages not to process the site with Jekyll
+- Ensures files starting with underscores (like Vite's `_assets/`) are served correctly
+
+## Manual Steps Required on GitHub
+
+### One-Time Setup (Required)
+
+1. **Go to Repository Settings**
+
+   - Navigate to: https://github.com/InformaticsMatters/observable-plot-scatter-poc/settings/pages
+
+2. **Configure GitHub Pages**
+
+   - Under "Build and deployment"
+   - **Source**: Select "**GitHub Actions**" from the dropdown
+   - (Don't select "Deploy from a branch" - we want to use the Actions workflow)
+
+3. **Wait for First Deployment**
+
+   - Push these changes to the `main` branch
+   - Go to the **Actions** tab to watch the deployment progress
+   - First deployment takes 2-3 minutes
+
+4. **Access Your Site**
+   - Once deployed, your app will be available at:
+   - https://informaticsmatters.github.io/observable-plot-scatter-poc/
+
+### That's It!
+
+After the initial setup, every push to `main` will automatically trigger a new deployment. No further manual steps needed.
+
+## Optional: Manual Deployment
+
+You can trigger a deployment manually without pushing code:
+
+1. Go to **Actions** tab: https://github.com/InformaticsMatters/observable-plot-scatter-poc/actions
+2. Click on "Deploy to GitHub Pages" workflow
+3. Click "Run workflow" button
+4. Select the `main` branch and click "Run workflow"
+
+## Troubleshooting
+
+### If deployment fails:
+
+- Check the Actions tab for error logs
+- Ensure the repository has Pages enabled in Settings
+- Verify that Actions have write permissions (Settings → Actions → General → Workflow permissions)
+
+### If site loads but shows 404:
+
+- Verify the `base` path in `vite.config.ts` matches your repository name
+- Check that all files are in the `dist` folder after build
+
+### To test locally before deploying:
+
+```sh
+pnpm run build
+pnpm run preview
+```
+
+This simulates the production build with the correct base path.

README.md

@@ -27,6 +27,36 @@ pnpm dev
 
 Open your browser and navigate to the local dev server (typically `http://localhost:5173`).
 
+## Deployment
+
+This project is set up to automatically deploy to GitHub Pages on every push to the `main` branch.
+
+**Live Demo:** https://informaticsmatters.github.io/observable-plot-scatter-poc/
+
+### Initial Setup (One-time)
+
+To enable GitHub Pages deployment, you need to configure your repository settings:
+
+1. Go to your GitHub repository
+2. Navigate to **Settings** → **Pages** (in the left sidebar)
+3. Under **Build and deployment**:
+   - **Source**: Select "GitHub Actions"
+4. That's it! The next push to `main` will trigger the deployment
+
+The workflow will:
+
+- Build the app using pnpm and Vite
+- Deploy the `dist` folder to GitHub Pages
+- Make your app available at `https://informaticsmatters.github.io/observable-plot-scatter-poc/`
+
+### Manual Deployment
+
+You can also trigger a deployment manually:
+
+1. Go to **Actions** tab in your repository
+2. Select the "Deploy to GitHub Pages" workflow
+3. Click "Run workflow"
+
 ## Usage
 
 ### Interactive Selection

public/.nojekyll

@@ -4,4 +4,7 @@ import react from "@vitejs/plugin-react";
 // https://vitejs.dev/config/
 export default defineConfig({
   plugins: [react()],
+  // Set base path for GitHub Pages deployment
+  // Format: /repository-name/
+  base: "/observable-plot-scatter-poc/",
 });