Avoid collisions between schema hot reloader and __refresh

packages/gatsby/src/bootstrap/schema-hot-reloader.ts

@@ -36,19 +36,28 @@ const maybeRebuildSchema = debounce(async (): Promise<void> => {
   activity.end()
 }, 1000)
 
-const snapshotInferenceMetadata = (): void => {
+function snapshotInferenceMetadata(): void {
   const { inferenceMetadata } = store.getState()
   lastMetadata = cloneDeep(inferenceMetadata)
 }
 
-export const bootstrapSchemaHotReloader = (): void => {
+export function bootstrapSchemaHotReloader(): void {
   // Snapshot inference metadata at the time of the last schema rebuild
   // (even if schema was rebuilt elsewhere)
   // Using the snapshot later to check if inferred types actually changed since the last rebuild
   snapshotInferenceMetadata()
   emitter.on(`SET_SCHEMA`, snapshotInferenceMetadata)
 
+  startSchemaHotReloader()
+}
+
+export function startSchemaHotReloader(): void {
   // Listen for node changes outside of a regular sourceNodes API call,
   // e.g. markdown file update via watcher
   emitter.on(`API_RUNNING_QUEUE_EMPTY`, maybeRebuildSchema)
 }
+
+export function stopSchemaHotReloader(): void {
+  emitter.off(`API_RUNNING_QUEUE_EMPTY`, maybeRebuildSchema)
+  maybeRebuildSchema.cancel()
+}

packages/gatsby/src/commands/develop.ts

@@ -31,13 +31,17 @@ import * as WorkerPool from "../utils/worker/pool"
 import http from "http"
 import https from "https"
 
-import { bootstrapSchemaHotReloader } from "../bootstrap/schema-hot-reloader"
+import {
+  bootstrapSchemaHotReloader,
+  startSchemaHotReloader,
+  stopSchemaHotReloader,
+} from "../bootstrap/schema-hot-reloader"
 import bootstrapPageHotReloader from "../bootstrap/page-hot-reloader"
 import { developStatic } from "./develop-static"
 import withResolverContext from "../schema/context"
 import sourceNodes from "../utils/source-nodes"
 import { createSchemaCustomization } from "../utils/create-schema-customization"
-import { rebuild } from "../schema"
+import { rebuild as rebuildSchema } from "../schema"
 import { websocketManager } from "../utils/websocket-manager"
 import getSslCert from "../utils/get-ssl-cert"
 import { slash } from "gatsby-core-utils"
@@ -204,6 +208,7 @@ async function startServer(program: IProgram): Promise<IServer> {
    **/
   const REFRESH_ENDPOINT = `/__refresh`
   const refresh = async (req: express.Request): Promise<void> => {
+    stopSchemaHotReloader()
     let activity = report.activityTimer(`createSchemaCustomization`, {})
     activity.start()
     await createSchemaCustomization({
@@ -218,8 +223,9 @@ async function startServer(program: IProgram): Promise<IServer> {
     activity.end()
     activity = report.activityTimer(`rebuild schema`)
     activity.start()
-    await rebuild({ parentSpan: activity })
+    await rebuildSchema({ parentSpan: activity })
     activity.end()
+    startSchemaHotReloader()
   }
   app.use(REFRESH_ENDPOINT, express.json())
   app.post(REFRESH_ENDPOINT, (req, res) => {