From e2bcd6e09ca5259a10a25096e23b1165925e4916 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Wed, 21 Oct 2026 01:10:17 -0700
Subject: [PATCH] Reuse Windows server native prebuilds across app version
 bumps (#31450)

* Measure Windows ARM qualification worker concurrency

* Reuse Windows server prebuilds across app version bumps

* Match native cache measurement to adhoc compiler settings

* Keep measured cache fix and remove temporary comparison modes
---
 .../scripts/orcad-windows-prebuild-cache.mjs  | 10 ++++++-
 .../orcad-windows-prebuild-cache.test.mjs     | 26 ++++++++++++++++++-
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/config/scripts/orcad-windows-prebuild-cache.mjs b/config/scripts/orcad-windows-prebuild-cache.mjs
index 3c3942ee544..de2112d0134 100644
--- a/config/scripts/orcad-windows-prebuild-cache.mjs
+++ b/config/scripts/orcad-windows-prebuild-cache.mjs
@@ -73,7 +73,15 @@ export function windowsPrebuildCacheIdentity({
   }
   const digest = createHash('sha256').update(JSON.stringify({ slot, imageOS, imageVersion }))
   for (const file of WINDOWS_PREBUILD_CACHE_INPUTS) {
-    digest.update(`\0${file}\0`).update(readFileSync(join(repository, file)))
+    const bytes = readFileSync(join(repository, file))
+    if (file === 'package.json') {
+      const manifest = JSON.parse(bytes.toString('utf8'))
+      // App versions do not affect the separately versioned node-pty binary.
+      delete manifest.version
+      digest.update(`\0${file}\0`).update(JSON.stringify(manifest))
+    } else {
+      digest.update(`\0${file}\0`).update(bytes)
+    }
   }
   return {
     slot,
diff --git a/config/scripts/orcad-windows-prebuild-cache.test.mjs b/config/scripts/orcad-windows-prebuild-cache.test.mjs
index 3abe13a08bc..189a0cdf94f 100644
--- a/config/scripts/orcad-windows-prebuild-cache.test.mjs
+++ b/config/scripts/orcad-windows-prebuild-cache.test.mjs
@@ -242,6 +242,25 @@ describe('Windows server prebuild cache inputs', () => {
     )
   })
 
+  it('reuses native binaries across app versions but invalidates every other manifest field', () => {
+    const repository = mkdtempSync(join(tmpdir(), 'orca-prebuild-version-key-'))
+    temporary.push(repository)
+    const source = resolve(import.meta.dirname, '../..')
+    for (const relative of WINDOWS_PREBUILD_CACHE_INPUTS) {
+      mkdirSync(dirname(join(repository, relative)), { recursive: true })
+      cpSync(join(source, relative), join(repository, relative))
+    }
+    const path = join(repository, 'package.json')
+    const manifest = JSON.parse(readFileSync(path, 'utf8'))
+    const before = windowsPrebuildCacheIdentity({ ...options, repository }).key
+    writeFileSync(path, JSON.stringify({ ...manifest, version: '999.0.0' }))
+    expect(windowsPrebuildCacheIdentity({ ...options, repository }).key).toBe(before)
+    for (const field of Object.keys(manifest).filter((field) => field !== 'version')) {
+      writeFileSync(path, JSON.stringify({ ...manifest, [field]: 'changed' }))
+      expect(windowsPrebuildCacheIdentity({ ...options, repository }).key).not.toBe(before)
+    }
+  })
+
   it.each(WINDOWS_PREBUILD_CACHE_INPUTS)('invalidates a changed %s input', (file) => {
     const repository = mkdtempSync(join(tmpdir(), 'orca-prebuild-key-'))
     temporary.push(repository)
@@ -253,7 +272,12 @@ describe('Windows server prebuild cache inputs', () => {
     const before = windowsPrebuildCacheIdentity({ ...options, repository }).key
     writeFileSync(
       join(repository, file),
-      `${readFileSync(join(repository, file), 'utf8')}\nchanged input`
+      file === 'package.json'
+        ? JSON.stringify({
+            ...JSON.parse(readFileSync(join(repository, file), 'utf8')),
+            engines: { node: 'changed' }
+          })
+        : `${readFileSync(join(repository, file), 'utf8')}\nchanged input`
     )
     expect(windowsPrebuildCacheIdentity({ ...options, repository }).key).not.toBe(before)
   })