feat(vercel): Add support for analytics (Audiences & Web Vitals) (#6148)

* feat(intergration/vercel): add vercel analytics support

* docs(intergration/vercel): add vercel analytics prop

* docs(intergration/vercel): bump version to 3.1.0

* Update packages/integrations/vercel/README.md

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* docs(intergration/vercel): add file name for example

* feat(intergration/vercel): convert analytics to ts and support in edge

* docs(intergration/vercel): move file names to code blocks as comments

* fix(intergration/vercel): remove unused import

* feat(intergration/vercel): add analytics support to static mode

* chore(intergration/vercel): revert version change

* style(intergration/vercel): add a blank line after astro import

* chore(intergration/vercel): generate file by changeset

* Update .changeset/eighty-bobcats-deliver.md

Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>

* Update packages/integrations/vercel/README.md

Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>

* Update packages/integrations/vercel/src/analytics.ts

Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>

* chore(intergration/vercel): simplify analytics script

---------

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>
Co-authored-by: Nate Moore <natemoo-re@users.noreply.github.com>
Co-authored-by: Chris Swithinbank <swithinbank@gmail.com>

4 files changed, 89 insertions, 5 deletions

diff --git a/packages/integrations/vercel/src/analytics.ts b/packages/integrations/vercel/src/analytics.ts
new file mode 100644
index 000000000..95dee83e3
--- /dev/null
+++ b/packages/integrations/vercel/src/analytics.ts
@@ -0,0 +1,64 @@
+import { inject } from '@vercel/analytics';
+import type { Metric } from 'web-vitals';
+import { getCLS, getFCP, getFID, getLCP, getTTFB } from 'web-vitals';
+
+const vitalsUrl = 'https://vitals.vercel-analytics.com/v1/vitals';
+
+type Options = { path: string; analyticsId: string };
+
+const getConnectionSpeed = () => {
+	return 'connection' in navigator &&
+		navigator['connection'] &&
+		'effectiveType' in (navigator['connection'] as unknown as { effectiveType: string })
+		? (navigator['connection'] as unknown as { effectiveType: string })['effectiveType']
+		: '';
+};
+
+const sendToAnalytics = (metric: Metric, options: Options) => {
+	const body = {
+		dsn: options.analyticsId,
+		id: metric.id,
+		page: options.path,
+		href: location.href,
+		event_name: metric.name,
+		value: metric.value.toString(),
+		speed: getConnectionSpeed(),
+	};
+	const blob = new Blob([new URLSearchParams(body).toString()], {
+		type: 'application/x-www-form-urlencoded',
+	});
+	if (navigator.sendBeacon) {
+		navigator.sendBeacon(vitalsUrl, blob);
+	} else
+		fetch(vitalsUrl, {
+			body: blob,
+			method: 'POST',
+			credentials: 'omit',
+			keepalive: true,
+		});
+};
+
+function webVitals() {
+	const analyticsId = (import.meta as any).env.PUBLIC_VERCEL_ANALYTICS_ID;
+	if (!analyticsId) {
+		console.error('[Analytics] VERCEL_ANALYTICS_ID not found');
+		return;
+	}
+	const options: Options = { path: window.location.pathname, analyticsId };
+	try {
+		getFID((metric) => sendToAnalytics(metric, options));
+		getTTFB((metric) => sendToAnalytics(metric, options));
+		getLCP((metric) => sendToAnalytics(metric, options));
+		getCLS((metric) => sendToAnalytics(metric, options));
+		getFCP((metric) => sendToAnalytics(metric, options));
+	} catch (err) {
+		console.error('[Analytics]', err);
+	}
+}
+
+const mode = (import.meta as any).env.MODE as 'development' | 'production';
+
+inject({ mode });
+if (mode === 'production') {
+	webVitals();
+}
diff --git a/packages/integrations/vercel/src/edge/adapter.ts b/packages/integrations/vercel/src/edge/adapter.ts
index 3f38a074e..3e9eb5929 100644
--- a/packages/integrations/vercel/src/edge/adapter.ts
+++ b/packages/integrations/vercel/src/edge/adapter.ts
@@ -1,4 +1,5 @@
 import type { AstroAdapter, AstroConfig, AstroIntegration } from 'astro';
+
 import esbuild from 'esbuild';
 import { relative as relativePath } from 'node:path';
 import { fileURLToPath } from 'node:url';
@@ -24,9 +25,13 @@ function getAdapter(): AstroAdapter {
 
 export interface VercelEdgeConfig {
 	includeFiles?: string[];
+	analytics?: boolean;
 }
 
-export default function vercelEdge({ includeFiles = [] }: VercelEdgeConfig = {}): AstroIntegration {
+export default function vercelEdge({
+	includeFiles = [],
+	analytics,
+}: VercelEdgeConfig = {}): AstroIntegration {
 	let _config: AstroConfig;
 	let buildTempFolder: URL;
 	let functionFolder: URL;
@@ -35,7 +40,10 @@ export default function vercelEdge({ includeFiles = [] }: VercelEdgeConfig = {})
 	return {
 		name: PACKAGE_NAME,
 		hooks: {
-			'astro:config:setup': ({ config, updateConfig }) => {
+			'astro:config:setup': ({ config, updateConfig, injectScript }) => {
+				if (analytics) {
+					injectScript('page', 'import "@astrojs/vercel/analytics"');
+				}
 				const outDir = getVercelOutput(config.root);
 				updateConfig({
 					outDir,
diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 3ff5eb3e5..884510516 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -19,11 +19,13 @@ function getAdapter(): AstroAdapter {
 export interface VercelServerlessConfig {
 	includeFiles?: string[];
 	excludeFiles?: string[];
+	analytics?: boolean;
 }
 
 export default function vercelServerless({
 	includeFiles,
 	excludeFiles,
+	analytics,
 }: VercelServerlessConfig = {}): AstroIntegration {
 	let _config: AstroConfig;
 	let buildTempFolder: URL;
@@ -33,7 +35,10 @@ export default function vercelServerless({
 	return {
 		name: PACKAGE_NAME,
 		hooks: {
-			'astro:config:setup': ({ config, updateConfig }) => {
+			'astro:config:setup': ({ config, updateConfig, injectScript }) => {
+				if (analytics) {
+					injectScript('page', 'import "@astrojs/vercel/analytics"');
+				}
 				const outDir = getVercelOutput(config.root);
 				updateConfig({
 					outDir,
diff --git a/packages/integrations/vercel/src/static/adapter.ts b/packages/integrations/vercel/src/static/adapter.ts
index 597c93626..28da5d4da 100644
--- a/packages/integrations/vercel/src/static/adapter.ts
+++ b/packages/integrations/vercel/src/static/adapter.ts
@@ -9,13 +9,20 @@ function getAdapter(): AstroAdapter {
 	return { name: PACKAGE_NAME };
 }
 
-export default function vercelStatic(): AstroIntegration {
+export interface VercelStaticConfig {
+	analytics?: boolean;
+}
+
+export default function vercelStatic({ analytics }: VercelStaticConfig = {}): AstroIntegration {
 	let _config: AstroConfig;
 
 	return {
 		name: '@astrojs/vercel',
 		hooks: {
-			'astro:config:setup': ({ config }) => {
+			'astro:config:setup': ({ config, injectScript }) => {
+				if (analytics) {
+					injectScript('page', 'import "@astrojs/vercel/analytics"');
+				}
 				config.outDir = new URL('./static/', getVercelOutput(config.root));
 				config.build.format = 'directory';
 			},