feat: add spa integration

packages/integrations/spa/client.js

@@ -0,0 +1,9 @@
+import listen from 'micromorph/spa'
+
+export default () => {
+	listen({
+		afterDiff() {
+			window.dispatchEvent(new CustomEvent('astro:locationchange'))
+		}
+	});
+}

packages/integrations/spa/package.json

@@ -0,0 +1,37 @@
+{
+  "name": "@astrojs/spa",
+  "description": "SPA Astro Integrations",
+  "version": "0.0.2",
+  "type": "module",
+  "types": "./dist/index.d.ts",
+  "author": "withastro",
+  "license": "MIT",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/withastro/astro.git",
+    "directory": "packages/integrations/turbolinks"
+  },
+  "keywords": [
+    "astro-component",
+    "performance"
+  ],
+  "bugs": "https://github.com/withastro/astro/issues",
+  "homepage": "https://astro.build",
+  "exports": {
+    ".": "./dist/index.js",
+    "./client.js": "./client.js",
+    "./package.json": "./package.json"
+  },
+  "scripts": {
+    "build": "astro-scripts build \"src/**/*.ts\" && tsc",
+    "build:ci": "astro-scripts build \"src/**/*.ts\"",
+    "dev": "astro-scripts dev \"src/**/*.ts\""
+  },
+  "dependencies": {
+    "micromorph": "^0.1.2"
+  },
+  "devDependencies": {
+    "astro": "workspace:*",
+    "astro-scripts": "workspace:*"
+  }
+}

packages/integrations/spa/src/index.ts

@@ -0,0 +1,15 @@
+import type { AstroIntegration } from 'astro';
+
+export default function createPlugin(): AstroIntegration {
+	return {
+		name: '@astrojs/spa',
+		hooks: {
+			'astro:config:setup': ({ injectScript }) => {
+				// This gets injected into the user's page, so we need to re-export Turbolinks
+				// from our own package so that package managers like pnpm don't get mad and
+				// can follow the import correctly.
+				injectScript('page', `import listen from "@astrojs/spa/client.js"; listen();`);
+			},
+		},
+	};
+}

packages/integrations/spa/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "include": ["src"],
+  "compilerOptions": {
+    "allowJs": true,
+    "module": "ES2020",
+    "outDir": "./dist",
+    "target": "ES2020"
+  }
+}