Implement custom client directives

.changeset/tall-eyes-vanish.md

@@ -0,0 +1,51 @@
+---
+'astro': minor
+---
+
+Integrations can add new `client:` directives through the `astro:config:setup` hook's `addClientDirective()` API. To enable this API, the user needs to set `experimental.customClientDirectives` to `true` in their config.
+
+```js
+import { defineConfig } from 'astro/config';
+import onClickDirective from 'astro-click-directive';
+
+export default defineConfig({
+  integrations: [onClickDirective()],
+  experimental: {
+    customClientDirectives: true
+  }
+});
+```
+
+```js
+export default function onClickDirective() {
+  return {
+    hooks: {
+      'astro:config:setup': ({ addClientDirective }) => {
+        addClientDirective({
+          name: 'click',
+          entrypoint: 'astro-click-directive/click.js'
+        });
+      },
+    }
+  }
+}
+```
+
+```astro
+<Counter client:click />
+```
+
+The client directive file (e.g. `astro-click-directive/click.js`) should export a function of type `ClientDirective`:
+
+```ts
+import type { ClientDirective } from 'astro'
+
+const clickDirective: ClientDirective = (load, opts, el) => {
+  window.addEventListener('click', async () => {
+    const hydrate = await load()
+    await hydrate()
+  }, { once: true })
+}
+
+export default clickDirective
+```

packages/astro/astro-jsx.d.ts

@@ -18,12 +18,13 @@ declare namespace astroHTML.JSX {
 		children: {};
 	}
 
-	interface IntrinsicAttributes extends AstroBuiltinProps, AstroBuiltinAttributes {
+	interface IntrinsicAttributes extends AstroBuiltinProps, AstroBuiltinAttributes, AstroClientDirectives {
 		slot?: string;
 		children?: Children;
 	}
 
 	type AstroBuiltinProps = import('./dist/@types/astro.js').AstroBuiltinProps;
+	type AstroClientDirectives = import('./dist/@types/astro.js').AstroClientDirectives;
 	type AstroBuiltinAttributes = import('./dist/@types/astro.js').AstroBuiltinAttributes;
 	type AstroDefineVarsAttribute = import('./dist/@types/astro.js').AstroDefineVarsAttribute;
 	type AstroScriptAttributes = import('./dist/@types/astro.js').AstroScriptAttributes &

packages/astro/e2e/custom-client-directives.test.js

@@ -0,0 +1,92 @@
+import { expect } from '@playwright/test';
+import { testFactory, waitForHydrate } from './test-utils.js';
+import testAdapter from '../test/test-adapter.js';
+
+const test = testFactory({
+	root: './fixtures/custom-client-directives/',
+});
+
+test.describe('Custom Client Directives - dev', () => {
+	let devServer;
+
+	test.beforeAll(async ({ astro }) => {
+		devServer = await astro.startDevServer();
+	});
+
+	test.afterAll(async () => {
+		await devServer.stop();
+	});
+
+	testClientDirectivesShared();
+});
+
+test.describe('Custom Client Directives - build static', () => {
+	let previewServer;
+
+	test.beforeAll(async ({ astro }) => {
+		await astro.build();
+		previewServer = await astro.preview();
+	});
+
+	test.afterAll(async () => {
+		await previewServer.stop();
+	});
+
+	testClientDirectivesShared();
+});
+
+test.describe('Custom Client Directives - build server', () => {
+	let previewServer;
+
+	test.beforeAll(async ({ astro }) => {
+		await astro.build({
+			adapter: testAdapter(),
+		});
+		previewServer = await astro.preview();
+	});
+
+	test.afterAll(async () => {
+		await previewServer.stop();
+	});
+
+	testClientDirectivesShared();
+});
+
+function testClientDirectivesShared() {
+	test('client:click should work', async ({ astro, page }) => {
+		await page.goto(astro.resolveUrl('/'));
+
+		const incrementBtn = page.locator('#client-click .increment');
+		const counterValue = page.locator('#client-click pre');
+
+		await expect(counterValue).toHaveText('0');
+
+		// Component only hydrates on first click
+		await Promise.all([waitForHydrate(page, counterValue), incrementBtn.click()]);
+
+		// Since first click only triggers hydration, this should stay 0
+		await expect(counterValue).toHaveText('0');
+		await incrementBtn.click();
+		// Hydrated, this should be 1
+		await expect(counterValue).toHaveText('1');
+	});
+
+	test('client:password should work', async ({ astro, page }) => {
+		await page.goto(astro.resolveUrl('/'));
+
+		const incrementBtn = page.locator('#client-password .increment');
+		const counterValue = page.locator('#client-password pre');
+
+		await expect(counterValue).toHaveText('0');
+		await incrementBtn.click();
+		// Not hydrated, so this should stay 0
+		await expect(counterValue).toHaveText('0');
+
+		// Type super cool password to activate password!
+		await Promise.all([waitForHydrate(page, counterValue), page.keyboard.type('hunter2')]);
+
+		await incrementBtn.click();
+		// Hydrated, this should be 1
+		await expect(counterValue).toHaveText('1');
+	});
+}

packages/astro/e2e/fixtures/custom-client-directives/astro.config.mjs

@@ -0,0 +1,38 @@
+import { defineConfig } from 'astro/config';
+import react from "@astrojs/react";
+import { fileURLToPath } from 'url';
+
+export default defineConfig({
+  integrations: [astroClientClickDirective(), astroClientPasswordDirective(), react()],
+  experimental: {
+    customClientDirectives: true
+  }
+});
+
+function astroClientClickDirective() {
+  return {
+    name: 'astro-client-click',
+    hooks: {
+      'astro:config:setup': (opts) => {
+        opts.addClientDirective({
+          name: 'click',
+          entrypoint: fileURLToPath(new URL('./client-click.js', import.meta.url))
+        });
+      }
+    }
+  };
+}
+
+function astroClientPasswordDirective() {
+  return {
+    name: 'astro-client-click',
+    hooks: {
+      'astro:config:setup': (opts) => {
+        opts.addClientDirective({
+          name: 'password',
+          entrypoint: fileURLToPath(new URL('./client-password.js', import.meta.url))
+        });
+      }
+    }
+  };
+}

packages/astro/e2e/fixtures/custom-client-directives/client-click.js

@@ -0,0 +1,7 @@
+// Hydrate on first click on the window
+export default (load) => {
+  window.addEventListener('click', async () => {
+    const hydrate = await load()
+    await hydrate()
+  }, { once: true })
+}

packages/astro/e2e/fixtures/custom-client-directives/client-password.js

@@ -0,0 +1,21 @@
+// Hydrate when the user types the correct password
+export default (load, options) => {
+  const password = options.value
+  let consecutiveMatch = 0
+
+  const handleKeydown = async (e) => {
+    if (e.key === password[consecutiveMatch]) {
+      consecutiveMatch++
+    } else {
+      consecutiveMatch = 0
+    }
+
+    if (consecutiveMatch === password.length) {
+      window.removeEventListener('keydown', handleKeydown)
+      const hydrate = await load()
+      await hydrate()
+    }
+  }
+
+  window.addEventListener('keydown', handleKeydown)
+}

packages/astro/e2e/fixtures/custom-client-directives/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "@test/custom-client-directives",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@astrojs/react": "workspace:*",
+    "astro": "workspace:*",
+    "react": "^18.0.0",
+    "react-dom": "^18.0.0"
+  }
+}

packages/astro/e2e/fixtures/custom-client-directives/src/client-directives-types.d.ts

@@ -0,0 +1,9 @@
+declare module 'astro' {
+  interface AstroClientDirectives {
+    'client:click'?: boolean
+    'client:password'?: string
+  }
+}
+
+// Make d.ts a module to similate common packaging setups where the entry `index.d.ts` would augment the types
+export {}

packages/astro/e2e/fixtures/custom-client-directives/src/components/Counter.jsx

@@ -0,0 +1,18 @@
+import React, { useState } from 'react';
+
+export default function Counter({ children, count: initialCount = 0, id }) {
+	const [count, setCount] = useState(initialCount);
+	const add = () => setCount((i) => i + 1);
+	const subtract = () => setCount((i) => i - 1);
+
+	return (
+		<>
+			<div id={id} className="counter">
+				<button className="decrement" onClick={subtract}>-</button>
+				<pre>{count}</pre>
+				<button className="increment" onClick={add}>+</button>
+			</div>
+			<div className="counter-message">{children}</div>
+		</>
+	);
+}

packages/astro/e2e/fixtures/custom-client-directives/src/pages/index.astro

@@ -0,0 +1,10 @@
+---
+import Counter from '../components/Counter.jsx';
+---
+
+<html>
+<body>
+  <Counter id="client-click" client:click>client:click</Counter>
+  <Counter id="client-password" client:password="hunter2">client:password</Counter>
+</body>
+</html>

packages/astro/e2e/fixtures/custom-client-directives/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "compilerOptions": {
+    // preserveSymlinks set to true so the augmented `declare module 'astro'` works.
+    // This is only needed because we link Astro locally.
+    "preserveSymlinks": true
+  },
+  "include": ["./src/**/*"]
+}

packages/astro/e2e/test-utils.js

@@ -55,7 +55,6 @@ export async function getErrorOverlayContent(page) {
 }
 
 /**
- * @param {import('@playwright/test').Locator} el
  * @returns {Promise<string>}
  */
 export async function getColor(el) {

packages/astro/package.json

@@ -137,6 +137,7 @@
     "devalue": "^4.2.0",
     "diff": "^5.1.0",
     "es-module-lexer": "^1.1.0",
+    "esbuild": "^0.17.18",
     "estree-walker": "3.0.0",
     "execa": "^6.1.0",
     "fast-glob": "^3.2.11",