[cli] Ignore VERCEL_ANALYTICS_ID if @vercel/speed-insights is present…

… on the project (#11305)

In the past, we used the `VERCEL_ANALYTICS_ID` environment variable with the previous Speed Insights feature on Vercel to activate specific logic in Next.js, Nuxt and Gatsby for collecting and sending web vitals data.

With the new Speed Insights, that's not required anymore.

We no longer want to set the environment variable when detecting the new `@vercel/speed-insights` package. 
This PR confirms that the variable is not set if the new package is detected.

.changeset/friendly-points-fold.md

@@ -0,0 +1,5 @@
+---
+'vercel': minor
+---
+
+Don't propagate legacy env VERCEL_ANALYTICS_ID if @vercel/speed-insights package is detected

packages/build-utils/src/get-installed-package-version.ts

@@ -0,0 +1,22 @@
+import debug from './debug';
+
+export async function getInstalledPackageVersion(
+  packageName: string,
+  path?: string | string[]
+): Promise<string | undefined> {
+  try {
+    const resolved = require.resolve(`${packageName}/package.json`, {
+      paths: path ? (Array.isArray(path) ? path : [path]) : [process.cwd()],
+    });
+
+    const version: string = require(resolved).version;
+
+    return version;
+  } catch (err) {
+    debug(
+      `Could not resolve package "${packageName}". Package is not installed.`,
+      err
+    );
+    return undefined;
+  }
+}

packages/build-utils/src/index.ts

@@ -111,3 +111,5 @@ export * from './types';
 export * from './errors';
 
 export { NODE_VERSIONS } from './fs/node-version';
+
+export { getInstalledPackageVersion } from './get-installed-package-version';

packages/cli/src/commands/build/index.ts

@@ -1,4 +1,4 @@
-import fs, { readJSON } from 'fs-extra';
+import fs from 'fs-extra';
 import chalk from 'chalk';
 import dotenv from 'dotenv';
 import semver from 'semver';
@@ -22,6 +22,7 @@ import {
   Cron,
   validateNpmrc,
   type FlagDefinitions,
+  getInstalledPackageVersion,
 } from '@vercel/build-utils';
 import {
   detectBuilders,
@@ -71,7 +72,6 @@ import { setMonorepoDefaultSettings } from '../../util/build/monorepo';
 import { help } from '../help';
 import { buildCommand } from './command';
 import { scrubArgv } from '../../util/build/scrub-argv';
-import { cwd } from 'process';
 
 type BuildResult = BuildResultV2 | BuildResultV3;
 
@@ -253,8 +253,11 @@ export default async function main(client: Client): Promise<number> {
       output.debug(`Loaded environment variables from "${envPath}"`);
     }
 
-    // For Vercel Legacy speed Insights support
+    // For legacy Speed Insights
     if (project.settings.analyticsId) {
+      // we pass the env down to the builder
+      // inside the builder we decide if we want to keep it or not
+
       envToUnset.add('VERCEL_ANALYTICS_ID');
       process.env.VERCEL_ANALYTICS_ID = project.settings.analyticsId;
     }
@@ -584,8 +587,7 @@ async function doBuild(
   }
 
   let needBuildsJsonOverride = false;
-  const speedInsightsVersion = await readInstalledVersion(
-    client,
+  const speedInsightsVersion = await getInstalledPackageVersion(
     '@vercel/speed-insights'
   );
   if (speedInsightsVersion) {
@@ -595,8 +597,7 @@ async function doBuild(
     };
     needBuildsJsonOverride = true;
   }
-  const webAnalyticsVersion = await readInstalledVersion(
-    client,
+  const webAnalyticsVersion = await getInstalledPackageVersion(
     '@vercel/analytics'
   );
   if (webAnalyticsVersion) {
@@ -859,21 +860,3 @@ async function writeFlagsJSON(
 async function writeBuildJson(buildsJson: BuildsManifest, outputDir: string) {
   await fs.writeJSON(join(outputDir, 'builds.json'), buildsJson, { spaces: 2 });
 }
-
-export async function readInstalledVersion(
-  { output }: Client,
-  pkgName: string
-): Promise<string | undefined> {
-  try {
-    const descriptorPath = require.resolve(`${pkgName}/package.json`, {
-      paths: [cwd()],
-    });
-    const descriptor = await readJSON(descriptorPath);
-    return descriptor?.version;
-  } catch (err) {
-    output.debug(
-      `Package ${pkgName} is not installed (failed to read its package.json: ${err})`
-    );
-  }
-  return;
-}

packages/cli/test/fixtures/unit/commands/build/nextjs-with-speed-insights-package/.gitignore

@@ -0,0 +1,2 @@
+!.vercel
+public/env.json

packages/cli/test/fixtures/unit/commands/build/nextjs-with-speed-insights-package/.vercel/project.json

@@ -0,0 +1,7 @@
+{
+  "orgId": ".",
+  "projectId": ".",
+  "settings": {
+    "analyticsId": "12345"
+  }
+}

packages/cli/test/fixtures/unit/commands/build/nextjs-with-speed-insights-package/next.config.js

@@ -0,0 +1,5 @@
+const fs = require('fs');
+fs.mkdirSync('public', { recursive: true });
+fs.writeFileSync('public/env.json', JSON.stringify(process.env));
+
+module.exports = {};