From 9c9fd6097aea36a6e8b06b0e8841df22896f9121 Mon Sep 17 00:00:00 2001
From: Ahn <27772165+ahnpnl@users.noreply.github.com>
Date: Tue, 27 Sep 2022 14:07:45 +0200
Subject: [PATCH] fix: merge config from `globals` with transformer config
 correctly (#3842)

Fixes #3841
---
 src/legacy/ts-jest-transformer.spec.ts | 2 +-
 src/legacy/ts-jest-transformer.ts      | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/legacy/ts-jest-transformer.spec.ts b/src/legacy/ts-jest-transformer.spec.ts
index f24a5df772..849e2d3041 100644
--- a/src/legacy/ts-jest-transformer.spec.ts
+++ b/src/legacy/ts-jest-transformer.spec.ts
@@ -304,7 +304,7 @@ describe('TsJestTransformer', () => {
     let tr!: TsJestTransformer
 
     beforeEach(() => {
-      tr = new TsJestTransformer()
+      tr = new TsJestTransformer({})
       jest.spyOn(TsJestCompiler.prototype, 'getResolvedModules').mockReturnValueOnce([])
     })
 
diff --git a/src/legacy/ts-jest-transformer.ts b/src/legacy/ts-jest-transformer.ts
index 7f118434f7..b4dbdc2a20 100644
--- a/src/legacy/ts-jest-transformer.ts
+++ b/src/legacy/ts-jest-transformer.ts
@@ -109,12 +109,17 @@ export class TsJestTransformer implements SyncTransformer {
         if (config.globals?.['ts-jest']) {
           this._logger.warn(Deprecations.GlobalsTsJestConfigOption)
         }
+        const jestGlobalsConfig = config.globals ?? {}
+        const tsJestGlobalsConfig = jestGlobalsConfig['ts-jest'] ?? {}
         const migratedConfig = this.tsJestConfig
           ? {
               ...config,
               globals: {
-                ...(config.globals ?? Object.create(null)),
-                'ts-jest': this.tsJestConfig,
+                ...jestGlobalsConfig,
+                'ts-jest': {
+                  ...tsJestGlobalsConfig,
+                  ...this.tsJestConfig,
+                },
               },
             }
           : config