From ff4b302ae34320dfe9ef317af406f5693efc6c07 Mon Sep 17 00:00:00 2001
From: ahnpnl <anhpnnd@gmail.com>
Date: Wed, 10 Jul 2024 02:18:29 +0200
Subject: [PATCH] fix: set `allowSyntheticDefaultImports` properly

Fixes #4156
---
 src/legacy/compiler/__snapshots__/ts-compiler.spec.ts.snap | 4 ++--
 src/legacy/compiler/ts-compiler.ts                         | 1 -
 src/legacy/config/config-set.spec.ts                       | 2 --
 src/legacy/config/config-set.ts                            | 5 -----
 4 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/src/legacy/compiler/__snapshots__/ts-compiler.spec.ts.snap b/src/legacy/compiler/__snapshots__/ts-compiler.spec.ts.snap
index 08d11b3d25..44eb97c2ed 100644
--- a/src/legacy/compiler/__snapshots__/ts-compiler.spec.ts.snap
+++ b/src/legacy/compiler/__snapshots__/ts-compiler.spec.ts.snap
@@ -18,7 +18,7 @@ exports[`TsCompiler getCompiledOutput isolatedModules false should compile codes
 
 exports[`TsCompiler getCompiledOutput isolatedModules false should compile codes with useESM {"babelConfig": false, "supportsStaticESM": true, "useESM": true} 1`] = `
 {
-  "allowSyntheticDefaultImports": true,
+  "allowSyntheticDefaultImports": undefined,
   "esModuleInterop": true,
   "module": 1,
 }
@@ -50,7 +50,7 @@ exports[`TsCompiler getCompiledOutput isolatedModules true should transpile code
 
 exports[`TsCompiler getCompiledOutput isolatedModules true should transpile code with config {"babelConfig": false, "supportsStaticESM": true, "useESM": true} 1`] = `
 {
-  "allowSyntheticDefaultImports": true,
+  "allowSyntheticDefaultImports": undefined,
   "esModuleInterop": true,
   "module": 1,
 }
diff --git a/src/legacy/compiler/ts-compiler.ts b/src/legacy/compiler/ts-compiler.ts
index 3dd57fc89d..43a8fa0202 100644
--- a/src/legacy/compiler/ts-compiler.ts
+++ b/src/legacy/compiler/ts-compiler.ts
@@ -172,7 +172,6 @@ export class TsCompiler implements TsCompilerInstance {
       ...compilerOptions,
       module: moduleKind,
       esModuleInterop: esModuleInterop ?? false,
-      allowSyntheticDefaultImports: esModuleInterop ?? compilerOptions.allowSyntheticDefaultImports,
     }
   }
 
diff --git a/src/legacy/config/config-set.spec.ts b/src/legacy/config/config-set.spec.ts
index ebcb658c1b..40ffb4c63c 100644
--- a/src/legacy/config/config-set.spec.ts
+++ b/src/legacy/config/config-set.spec.ts
@@ -97,7 +97,6 @@ describe('parsedTsConfig', () => {
 
     expect(cs.parsedTsConfig.options).toMatchObject({
       module: ts.ModuleKind.AMD,
-      allowSyntheticDefaultImports: true,
       esModuleInterop: false,
     })
     expect(target.lines.warn.join()).toEqual(expect.stringContaining(Errors.ConfigNoModuleInterop))
@@ -839,7 +838,6 @@ describe('_resolveTsConfig', () => {
         expect(readConfig.mock.calls[0][0]).toBe(tscfgPathStub)
         expect(parseConfig.mock.calls[0][2]).toBe('/root')
         expect(parseConfig.mock.calls[0][4]).toBe(tscfgPathStub)
-        expect(conf.options.allowSyntheticDefaultImports).toEqual(true)
         expect(conf.errors).toMatchSnapshot()
       })
 
diff --git a/src/legacy/config/config-set.ts b/src/legacy/config/config-set.ts
index 10165f315d..a35939c099 100644
--- a/src/legacy/config/config-set.ts
+++ b/src/legacy/config/config-set.ts
@@ -487,11 +487,6 @@ export class ConfigSet {
         start: undefined,
         length: undefined,
       })
-      // at least enable synthetic default imports (except if it's set in the input config)
-      /* istanbul ignore next (already covered in unit test) */
-      if (!('allowSyntheticDefaultImports' in finalOptions)) {
-        finalOptions.allowSyntheticDefaultImports = true
-      }
     }
     // Make sure when allowJs is enabled, outDir is required to have when using allowJs: true
     if (finalOptions.allowJs && !finalOptions.outDir) {