feat(gatsby): invite people with long page query running to try out q…

…uery on demand feature (#28181)

packages/gatsby/src/services/run-page-queries.ts

@@ -2,6 +2,13 @@ import { processPageQueries } from "../query"
 import reporter from "gatsby-cli/lib/reporter"
 import { IQueryRunningContext } from "../state-machines/query-running/types"
 import { assertStore } from "../utils/assert-store"
+import {
+  showExperimentNoticeAfterTimeout,
+  CancelExperimentNoticeCallbackOrUndefined,
+} from "../utils/show-experiment-notice"
+import { isCI } from "gatsby-core-utils"
+
+const TWO_MINUTES = 2 * 60 * 1000
 
 export async function runPageQueries({
   parentSpan,
@@ -35,12 +42,40 @@ export async function runPageQueries({
   )
 
   activity.start()
+
+  let cancelNotice: CancelExperimentNoticeCallbackOrUndefined
+  if (
+    process.env.gatsby_executing_command === `develop` &&
+    !process.env.GATSBY_EXPERIMENTAL_QUERY_ON_DEMAND &&
+    !isCI()
+  ) {
+    cancelNotice = showExperimentNoticeAfterTimeout(
+      `queryOnDemand`,
+      reporter.stripIndent(`
+        Your local development experience is about to get better, faster, and stronger!
+
+        Your friendly Gatsby maintainers detected your site takes longer than ideal to run page queries. We're working right now to improve this.
+
+        If you're interested in trialing out one of these future improvements *today* which should make your local development experience faster, go ahead and run your site with QUERY_ON_DEMAND enabled.
+
+        GATSBY_EXPERIMENTAL_QUERY_ON_DEMAND=true gatsby develop
+
+        Please do let us know how it goes (good, bad, or otherwise) and learn more about it at https://gatsby.dev/query-on-demand-feedback
+      `),
+      TWO_MINUTES
+    )
+  }
+
   await processPageQueries(pageQueryIds, {
     state,
     activity,
     graphqlRunner,
     graphqlTracing: program?.graphqlTracing,
   })
 
+  if (cancelNotice) {
+    cancelNotice()
+  }
+
   activity.done()
 }