feat(gatsby): Capture number of compiled TS files in Telemetry

packages/gatsby-telemetry/src/telemetry.ts

@@ -111,6 +111,7 @@ export interface ITelemetryTagsPayload {
     SSRCount?: number
     DSGCount?: number
     SSGCount?: number
+    compiledTSFilesCount?: number
   }
   errorV2?: IStructuredErrorV2
   valueString?: string

packages/gatsby/src/utils/parcel/compile-gatsby-files.ts

@@ -2,6 +2,7 @@ import { Parcel } from "@parcel/core"
 import type { Diagnostic } from "@parcel/diagnostic"
 import reporter from "gatsby-cli/lib/reporter"
 import { ensureDir, emptyDir, existsSync } from "fs-extra"
+import telemetry from "gatsby-telemetry"
 
 export const COMPILED_CACHE_DIR = `.cache/compiled`
 export const PARCEL_CACHE_DIR = `.cache/.parcel-cache`
@@ -46,7 +47,20 @@ export async function compileGatsbyFiles(siteRoot: string): Promise<void> {
     const distDir = `${siteRoot}/${COMPILED_CACHE_DIR}`
     await ensureDir(distDir)
     await emptyDir(distDir)
-    await parcel.run()
+    const { bundleGraph } = await parcel.run()
+
+    if (telemetry.isTrackingEnabled()) {
+      const bundles = bundleGraph.getBundles()
+      let compiledTSFilesCount = 0
+      for (const bundle of bundles) {
+        if (bundle?.getMainEntry()?.filePath?.endsWith(`.ts`)) {
+          compiledTSFilesCount = compiledTSFilesCount + 1
+        }
+      }
+      telemetry.addSiteMeasurement(`PARCEL_COMPILATION_END`, {
+        compiledTSFilesCount,
+      })
+    }
   } catch (error) {
     if (error.diagnostics) {
       handleErrors(error.diagnostics)

packages/gatsby/src/utils/worker/__tests__/config.ts

@@ -9,6 +9,7 @@ jest.mock(`gatsby-telemetry`, () => {
   return {
     decorateEvent: jest.fn(),
     trackCli: jest.fn(),
+    isTrackingEnabled: jest.fn(),
   }
 })
 

packages/gatsby/src/utils/worker/__tests__/datastore.ts

@@ -12,6 +12,7 @@ jest.mock(`gatsby-telemetry`, () => {
     decorateEvent: jest.fn(),
     trackError: jest.fn(),
     trackCli: jest.fn(),
+    isTrackingEnabled: jest.fn(),
   }
 })
 

packages/gatsby/src/utils/worker/__tests__/jobs.ts

@@ -11,6 +11,7 @@ jest.mock(`gatsby-telemetry`, () => {
   return {
     decorateEvent: jest.fn(),
     trackCli: jest.fn(),
+    isTrackingEnabled: jest.fn(),
   }
 })
 

packages/gatsby/src/utils/worker/__tests__/queries.ts

@@ -51,6 +51,7 @@ jest.mock(`gatsby-telemetry`, () => {
     decorateEvent: jest.fn(),
     trackError: jest.fn(),
     trackCli: jest.fn(),
+    isTrackingEnabled: jest.fn(),
   }
 })
 

packages/gatsby/src/utils/worker/__tests__/schema.ts

@@ -44,6 +44,7 @@ jest.mock(`gatsby-telemetry`, () => {
     decorateEvent: jest.fn(),
     trackError: jest.fn(),
     trackCli: jest.fn(),
+    isTrackingEnabled: jest.fn(),
   }
 })
 

packages/gatsby/src/utils/worker/__tests__/share-state.ts

@@ -12,6 +12,7 @@ jest.mock(`gatsby-telemetry`, () => {
     decorateEvent: jest.fn(),
     trackError: jest.fn(),
     trackCli: jest.fn(),
+    isTrackingEnabled: jest.fn(),
   }
 })