From d2420aaf42055097dfe1e6a54bf3701214b06402 Mon Sep 17 00:00:00 2001
From: BIKI DAS <bikid475@gmail.com>
Date: Sat, 7 Jan 2023 18:24:02 +0530
Subject: [PATCH] JestRuntime:-Using scriptTransformer cache in jest-runner
 (#13735)

---
 CHANGELOG.md                       |  1 +
 packages/jest-runtime/src/index.ts | 29 ++++++++---------------------
 2 files changed, 9 insertions(+), 21 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d84c581f30c8..067791482e22 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@
 - `[jest-mock]` fix mockReset and resetAllMocks undefined return ([#13692](https://github.com/facebook/jest/pull/13692))
 - `[jest-resolve]` Add global paths to `require.resolve.paths` ([#13633](https://github.com/facebook/jest/pull/13633))
 - `[jest-runtime]` Support Wasm files that import JS resources ([#13608](https://github.com/facebook/jest/pull/13608))
+- `[jest-runtime]` Using the scriptTransformer cache in jest-runner ([#13735](https://github.com/facebook/jest/pull/13735))
 - `[jest-snapshot]` Make sure to import `babel` outside of the sandbox ([#13694](https://github.com/facebook/jest/pull/13694))
 
 ### Chore & Maintenance
diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index dcca9ceef75d..2729651f622a 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -42,7 +42,6 @@ import {
   CallerTransformOptions,
   ScriptTransformer,
   ShouldInstrumentOptions,
-  TransformResult,
   TransformationOptions,
   handlePotentialSyntaxError,
   shouldInstrument,
@@ -1574,14 +1573,7 @@ export default class Runtime {
       return source;
     }
 
-    let transformedFile: TransformResult | undefined =
-      this._fileTransforms.get(filename);
-
-    if (transformedFile) {
-      return transformedFile.code;
-    }
-
-    transformedFile = this._scriptTransformer.transform(
+    const transformedFile = this._scriptTransformer.transform(
       filename,
       this._getFullTransformationOptions(options),
       source,
@@ -1608,23 +1600,18 @@ export default class Runtime {
       return source;
     }
 
-    let transformedFile: TransformResult | undefined =
-      this._fileTransforms.get(filename);
-
-    if (transformedFile) {
-      return transformedFile.code;
-    }
-
-    transformedFile = await this._scriptTransformer.transformAsync(
+    const transformedFile = await this._scriptTransformer.transformAsync(
       filename,
       this._getFullTransformationOptions(options),
       source,
     );
 
-    this._fileTransforms.set(filename, {
-      ...transformedFile,
-      wrapperLength: 0,
-    });
+    if (this._fileTransforms.get(filename)?.code !== transformedFile.code) {
+      this._fileTransforms.set(filename, {
+        ...transformedFile,
+        wrapperLength: 0,
+      });
+    }
 
     if (transformedFile.sourceMapPath) {
       this._sourceMapRegistry.set(filename, transformedFile.sourceMapPath);