From f8faa4b53299c422af2b92d02ccd7bb016e66332 Mon Sep 17 00:00:00 2001
From: William Swanson <swansontec@gmail.com>
Date: Fri, 15 Feb 2019 05:39:22 -0800
Subject: [PATCH] Allow config files to contain non-default exports (#2673)

Before, if a config file contained exports other than `default`, rollup would break. Now, it correctly ignores these irrelevant config-file exports.
---
 bin/src/run/loadConfigFile.ts                | 7 ++++++-
 test/cli/samples/config-es6/rollup.config.js | 2 ++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/bin/src/run/loadConfigFile.ts b/bin/src/run/loadConfigFile.ts
index 8144b6dfd4c..53d1adbc1a6 100644
--- a/bin/src/run/loadConfigFile.ts
+++ b/bin/src/run/loadConfigFile.ts
@@ -10,6 +10,10 @@ interface NodeModuleWithCompile extends NodeModule {
 	_compile(code: string, filename: string): any;
 }
 
+function interopDefault<T>(ex: T): T {
+	return ex && typeof ex === 'object' && 'default' in ex ? (ex as any).default : ex;
+}
+
 export default function loadConfigFile(
 	configFile: string,
 	commandOptions: any = {}
@@ -33,6 +37,7 @@ export default function loadConfigFile(
 			}
 
 			return bundle.generate({
+				exports: 'named',
 				format: 'cjs'
 			});
 		})
@@ -49,7 +54,7 @@ export default function loadConfigFile(
 
 			delete require.cache[configFile];
 
-			return Promise.resolve(require(configFile))
+			return Promise.resolve(interopDefault(require(configFile)))
 				.then(configFileContent => {
 					if (typeof configFileContent === 'function') {
 						return configFileContent(commandOptions);
diff --git a/test/cli/samples/config-es6/rollup.config.js b/test/cli/samples/config-es6/rollup.config.js
index 22bbdf2e99b..036e93d68b9 100644
--- a/test/cli/samples/config-es6/rollup.config.js
+++ b/test/cli/samples/config-es6/rollup.config.js
@@ -1,5 +1,7 @@
 import replace from 'rollup-plugin-replace';
 
+export const ignoresNonDefaultExports = true
+
 export default {
 	input: 'main.js',
 	output: {