From a8de326aaeedb3a0287f2841a594460027fdc70d Mon Sep 17 00:00:00 2001
From: Tony Valderrama <tonyvalderrama@tuplehealth.com>
Date: Tue, 1 Aug 2017 18:12:56 -0700
Subject: [PATCH] Cache tsconfig when generating per-file cache key.

---
 src/preprocessor.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/preprocessor.ts b/src/preprocessor.ts
index 083dcced98..28fe8a4dad 100644
--- a/src/preprocessor.ts
+++ b/src/preprocessor.ts
@@ -78,6 +78,7 @@ export function process(
     return src;
 }
 
+let tsConfig = undefined;
 export function getCacheKey(
     fileData: string,
     filePath: Path,
@@ -85,7 +86,9 @@ export function getCacheKey(
     options: TransformOptions = { instrument: false }): string {
 
     const jestConfig: JestConfig = JSON.parse(configStr);
-    const tsConfig = getTSConfig(jestConfig.globals, options.instrument);
+    if (!tsConfig) {
+        tsConfig = getTSConfig(jestConfig.globals, options.instrument);
+    }
 
     return crypto.createHash('md5')
         .update(JSON.stringify(tsConfig), 'utf8')