fix(compiler): do not force module kind if piping babel

src/config/config-set.spec.ts

@@ -311,6 +311,25 @@ message TS151001: If you have issues related to imports, you should consider set
 "
 `)
   })
+
+  it('should not warn neither set synth. default imports if using babel', () => {
+    const target = logTargetMock()
+    target.clear()
+    const cs = createConfigSet({
+      tsJestConfig: {
+        tsConfig: { module: 'amd', esModuleInterop: false } as any,
+        diagnostics: { warnOnly: true, pretty: false },
+        babelConfig: { babelrc: false },
+      },
+      resolve: null,
+    })
+    expect(cs.typescript.options).toMatchObject({
+      module: ModuleKind.AMD,
+      esModuleInterop: false,
+    })
+    expect(cs.typescript.options.allowSyntheticDefaultImports).toBeFalsy()
+    expect(target.lines.warn).toHaveLength(0)
+  })
 }) // typescript
 
 describe('resolvePath', () => {

src/config/config-set.ts

@@ -453,7 +453,7 @@ export class ConfigSet {
 
   @Memoize()
   get overriddenCompilerOptions(): Partial<CompilerOptions> {
-    return {
+    const options: Partial<CompilerOptions> = {
       // we handle sourcemaps this way and not another
       sourceMap: true,
       inlineSourceMap: false,
@@ -462,8 +462,6 @@ export class ConfigSet {
       declaration: false,
       noEmit: false,
       outDir: '$$ts-jest$$',
-      // commonjs is required for jest
-      module: this.compilerModule.ModuleKind.CommonJS,
       // else istanbul related will be dropped
       removeComments: false,
       // to clear out else it's buggy
@@ -475,6 +473,12 @@ export class ConfigSet {
       emitDeclarationOnly: undefined,
       sourceRoot: undefined,
     }
+    // force the module kind if not piping babel-jest
+    if (!this.tsJest.babelConfig) {
+      // commonjs is required for jest
+      options.module = this.compilerModule.ModuleKind.CommonJS
+    }
+    return options
   }
 
   @Memoize()
@@ -627,6 +631,7 @@ export class ConfigSet {
       : ts.ModuleKind.ESNext
     const moduleValue = finalOptions.module == null ? defaultModule : finalOptions.module
     if (
+      'module' in forcedOptions &&
       moduleValue !== forcedOptions.module &&
       !(finalOptions.esModuleInterop || finalOptions.allowSyntheticDefaultImports)
     ) {