From d6d11ecab707e1fd42f8e722a48b8249529d1f4d Mon Sep 17 00:00:00 2001
From: Andrew Bradley <cspotcode@gmail.com>
Date: Fri, 21 Jan 2022 14:21:52 -0500
Subject: [PATCH 1/2] initial commit

---
 package-lock.json |  5 +++++
 package.json      |  1 +
 src/index.ts      |  3 ++-
 src/util.ts       | 18 ++++++++++++++++++
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/package-lock.json b/package-lock.json
index bb7dd8c91..6b088bd73 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4882,6 +4882,11 @@
       "integrity": "sha512-HjSDRw6gZE5JMggctHBcjVak08+KEVhSIiDzFnT9S9aegmp85S/bReBVTb4QTFaRNptJ9kuYaNhnbNEOkbKb/A==",
       "dev": true
     },
+    "v8-compile-cache-lib": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/v8-compile-cache-lib/-/v8-compile-cache-lib-3.0.0.tgz",
+      "integrity": "sha512-mpSYqfsFvASnSn5qMiwrr4VKfumbPyONLCOPmsR3A6pTY/r0+tSaVbgPWSAIuzbk3lCTa+FForeTiO+wBQGkjA=="
+    },
     "validate-npm-package-license": {
       "version": "3.0.4",
       "resolved": "https://registry.npmjs.org/validate-npm-package-license/-/validate-npm-package-license-3.0.4.tgz",
diff --git a/package.json b/package.json
index e3e64415c..320ee79fc 100644
--- a/package.json
+++ b/package.json
@@ -164,6 +164,7 @@
     "create-require": "^1.1.0",
     "diff": "^4.0.1",
     "make-error": "^1.1.1",
+    "v8-compile-cache-lib": "^3.0.0",
     "yn": "3.1.1"
   },
   "prettier": {
diff --git a/src/index.ts b/src/index.ts
index 41959f7c2..613775083 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -10,6 +10,7 @@ import type * as _ts from 'typescript';
 import type { Transpiler, TranspilerFactory } from './transpilers/types';
 import {
   assign,
+  attemptRequireWithV8CompileCache,
   cachedLookup,
   normalizeSlashes,
   parse,
@@ -568,7 +569,7 @@ export function create(rawOptions: CreateOptions = {}): Service {
     const compiler = require.resolve(name || 'typescript', {
       paths: [relativeToPath, __dirname],
     });
-    const ts: typeof _ts = require(compiler);
+    const ts: typeof _ts = attemptRequireWithV8CompileCache(require, compiler);
     return { compiler, ts };
   }
 
diff --git a/src/util.ts b/src/util.ts
index da6cc53be..edff62d5e 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -90,3 +90,21 @@ export function cachedLookup<T, R>(fn: (arg: T) => R): (arg: T) => R {
     return cache.get(arg)!;
   };
 }
+
+/**
+ * @internal
+ * Require something with v8-compile-cache, which should make subsequent requires faster.
+ * Do lots of error-handling so that, worst case, we require without the cache, and users are not blocked.
+ */
+export function attemptRequireWithV8CompileCache(requireFn: typeof require, specifier: string) {
+  try {
+    const v8CC = (require('v8-compile-cache-lib') as typeof import('v8-compile-cache-lib')).install();
+    try {
+      return requireFn(specifier);
+    } finally {
+      v8CC?.uninstall();
+    }
+  } catch(e) {
+    return requireFn(specifier);
+  }
+}

From 9ecc03743f4e187289f01933c979ce8ffab52e79 Mon Sep 17 00:00:00 2001
From: Andrew Bradley <cspotcode@gmail.com>
Date: Fri, 21 Jan 2022 14:31:36 -0500
Subject: [PATCH 2/2] lint-fix

---
 src/util.ts | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/util.ts b/src/util.ts
index edff62d5e..217dc6669 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -96,15 +96,20 @@ export function cachedLookup<T, R>(fn: (arg: T) => R): (arg: T) => R {
  * Require something with v8-compile-cache, which should make subsequent requires faster.
  * Do lots of error-handling so that, worst case, we require without the cache, and users are not blocked.
  */
-export function attemptRequireWithV8CompileCache(requireFn: typeof require, specifier: string) {
+export function attemptRequireWithV8CompileCache(
+  requireFn: typeof require,
+  specifier: string
+) {
   try {
-    const v8CC = (require('v8-compile-cache-lib') as typeof import('v8-compile-cache-lib')).install();
+    const v8CC = (
+      require('v8-compile-cache-lib') as typeof import('v8-compile-cache-lib')
+    ).install();
     try {
       return requireFn(specifier);
     } finally {
       v8CC?.uninstall();
     }
-  } catch(e) {
+  } catch (e) {
     return requireFn(specifier);
   }
 }