feat(devtools): respect DO_NOT_TRACK environment variable (#1064)

Author: antfubot

README.md

@@ -177,6 +177,8 @@ Nuxt DevTools collects anonymous telemetry data about general usage. This helps
 
 Nuxt DevTools' telemetry data is piped through [Nuxt Telemetry](https://github.com/nuxt/telemetry), meaning that Nuxt DevTools will respect your local and global Nuxt Telemetry settings. You can also opt-out Nuxt DevTools' telemetry in the Nuxt DevTools settings.
 
+Nuxt DevTools also respects the [`DO_NOT_TRACK`](https://donottrack.sh/) environment variable convention — set `DO_NOT_TRACK=1` in your environment to disable Nuxt DevTools telemetry regardless of any other setting.
+
 The data we collect is completely anonymous, not traceable to the source (using hash+seed), and only meaningful in aggregate form. No data we collect is personally identifiable or trackable.
 
 ### Events

packages/devtools/src/server-rpc/telemetry.ts

@@ -8,6 +8,17 @@ const SEND_DELAY = 5_000
 
 type ArgumentsType<T> = T extends (...args: infer A) => any ? A : never
 
+/**
+ * Whether the user has opted out of tracking via the `DO_NOT_TRACK`
+ * environment variable convention.
+ *
+ * @see https://donottrack.sh/
+ */
+function isDoNotTrackEnabled() {
+  const value = process.env.DO_NOT_TRACK
+  return value === '1' || value?.toLowerCase() === 'true'
+}
+
 function throttle<T extends () => any>(fn: T, delay: number) {
   let timer: ReturnType<typeof setTimeout> | undefined
 
@@ -28,7 +39,7 @@ const throttledSend = throttle(() => {
 }, SEND_DELAY)
 
 export function setupTelemetryRPC({ nuxt, options }: NuxtDevtoolsServerContext) {
-  if (options.telemetry !== false) {
+  if (options.telemetry !== false && !isDoNotTrackEnabled()) {
     // Only when global telemetry is enabled, the hook will be called
     nuxt.hook('telemetry:setup', (t) => {
       telemetry = t
@@ -58,6 +69,9 @@ export function telemetryEvent(payload: object, immediate = false) {
   if (getOptions()?.behavior.telemetry === false)
     return
 
+  if (isDoNotTrackEnabled())
+    return
+
   telemetry.createEvent('devtools', payload)
 
   if (immediate)