From 31410c875cc0161281f61add98e068a6d7e0acf1 Mon Sep 17 00:00:00 2001
From: Kirill Romanov <djaler1@gmail.com>
Date: Thu, 7 Nov 2019 22:56:54 +0300
Subject: [PATCH] feat(babel-transpiler): support object-style babel.config.js
 (#1762)

The babel transpiler will now also work with babel.config.js files that export object instead of function.
---
 packages/babel-transpiler/src/BabelConfigReader.ts       | 9 +++++++--
 .../test/integration/BabelProjects.it.spec.ts            | 8 +++++++-
 .../babelProjectWithBabelConfigJsObject/babel.config.js  | 3 +++
 .../expectedResult/foo.js                                | 1 +
 .../expectedResult/main.js                               | 1 +
 .../babelProjectWithBabelConfigJsObject/source/foo.ts    | 1 +
 .../babelProjectWithBabelConfigJsObject/source/main.ts   | 1 +
 7 files changed, 21 insertions(+), 3 deletions(-)
 create mode 100644 packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/babel.config.js
 create mode 100644 packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/foo.js
 create mode 100644 packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/main.js
 create mode 100644 packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/foo.ts
 create mode 100644 packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/main.ts

diff --git a/packages/babel-transpiler/src/BabelConfigReader.ts b/packages/babel-transpiler/src/BabelConfigReader.ts
index 9e5a35ac68..8d5eccba02 100644
--- a/packages/babel-transpiler/src/BabelConfigReader.ts
+++ b/packages/babel-transpiler/src/BabelConfigReader.ts
@@ -50,8 +50,13 @@ export class BabelConfigReader {
             return require(babelrcPath) as babel.TransformOptions;
           }
           if (path.basename(babelrcPath) === 'babel.config.js') {
-            const config: babel.ConfigFunction = require(babelrcPath);
-            return config(optionsApi as babel.ConfigAPI);
+            const config = require(babelrcPath);
+            if (typeof config === 'function') {
+              const configFunction = config as babel.ConfigFunction;
+              return configFunction(optionsApi as babel.ConfigAPI);
+            } else {
+              return config as babel.TransformOptions;
+            }
           }
           return JSON.parse(fs.readFileSync(babelrcPath, 'utf8')) as babel.TransformOptions;
         } catch (error) {
diff --git a/packages/babel-transpiler/test/integration/BabelProjects.it.spec.ts b/packages/babel-transpiler/test/integration/BabelProjects.it.spec.ts
index 2af9d9356f..2e75c8a477 100644
--- a/packages/babel-transpiler/test/integration/BabelProjects.it.spec.ts
+++ b/packages/babel-transpiler/test/integration/BabelProjects.it.spec.ts
@@ -63,7 +63,7 @@ describe('Project with binary files', () => {
 describe('Different extensions', () => {
   describeIntegrationTest('differentExtensions');
 });
-describe('A Babel project with babel.config.js config file', () => {
+describe('A Babel project with babel.config.js config file that exports function', () => {
   const noop = () => {};
   describeIntegrationTest('babelProjectWithBabelConfigJs', {
     extensions: ['.ts'],
@@ -71,6 +71,12 @@ describe('A Babel project with babel.config.js config file', () => {
     optionsFile: 'babel.config.js'
   });
 });
+describe('A Babel project with babel.config.js config file that exports object', () => {
+  describeIntegrationTest('babelProjectWithBabelConfigJsObject', {
+    extensions: ['.ts'],
+    optionsFile: 'babel.config.js'
+  });
+});
 describe('A Babel project with .babelrc.js config file', () => {
   describeIntegrationTest('babelProjectWithBabelRcJs', {
     extensions: ['.ts'],
diff --git a/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/babel.config.js b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/babel.config.js
new file mode 100644
index 0000000000..b64fcf0f34
--- /dev/null
+++ b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/babel.config.js
@@ -0,0 +1,3 @@
+module.exports = {
+  presets: ["@babel/preset-typescript"]
+}
diff --git a/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/foo.js b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/foo.js
new file mode 100644
index 0000000000..c95d6c53a9
--- /dev/null
+++ b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/foo.js
@@ -0,0 +1 @@
+export const foo = 4;
\ No newline at end of file
diff --git a/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/main.js b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/main.js
new file mode 100644
index 0000000000..c4ad81e932
--- /dev/null
+++ b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/expectedResult/main.js
@@ -0,0 +1 @@
+const x = 0;
\ No newline at end of file
diff --git a/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/foo.ts b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/foo.ts
new file mode 100644
index 0000000000..914e3092cb
--- /dev/null
+++ b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/foo.ts
@@ -0,0 +1 @@
+export const foo: number = 4;
\ No newline at end of file
diff --git a/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/main.ts b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/main.ts
new file mode 100644
index 0000000000..cacb9b4964
--- /dev/null
+++ b/packages/babel-transpiler/testResources/babelProjectWithBabelConfigJsObject/source/main.ts
@@ -0,0 +1 @@
+const x: number = 0;
\ No newline at end of file