From f659aaa35ed003c392ab54e5895bfd101cd64913 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Fri, 29 Mar 2019 18:09:11 +0200
Subject: [PATCH 1/3] support Node-style format aliases

---
 src/utils/mergeOptions.ts | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/utils/mergeOptions.ts b/src/utils/mergeOptions.ts
index 8f8c2629a98..af66b6c8a50 100644
--- a/src/utils/mergeOptions.ts
+++ b/src/utils/mergeOptions.ts
@@ -229,7 +229,18 @@ function getOutputOptions(
 	command: GenericConfigObject = {}
 ): OutputOptions {
 	const getOption = createGetOption(config, command);
-	const format = getOption('format');
+	let format = getOption('format');
+
+	// Handle format aliases
+	switch (format) {
+		case 'esm':
+		case 'module':
+			format = 'es';
+			break;
+		case 'commonjs':
+			format = 'cjs';
+			break;
+	}
 
 	return {
 		amd: { ...config.amd, ...command.amd },

From 00d2f40e667ad2285fd0267a4dcd0b10dc8f8358 Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 1 Apr 2019 18:15:58 +0200
Subject: [PATCH 2/3] remove unnecessary fallback

---
 src/utils/mergeOptions.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/utils/mergeOptions.ts b/src/utils/mergeOptions.ts
index af66b6c8a50..00455edc6e9 100644
--- a/src/utils/mergeOptions.ts
+++ b/src/utils/mergeOptions.ts
@@ -239,7 +239,6 @@ function getOutputOptions(
 			break;
 		case 'commonjs':
 			format = 'cjs';
-			break;
 	}
 
 	return {

From 8b85f5843240bb5e781028c9a1afcfdcff21e81c Mon Sep 17 00:00:00 2001
From: Guy Bedford <guybedford@gmail.com>
Date: Mon, 1 Apr 2019 18:31:53 +0200
Subject: [PATCH 3/3] add formats to typings

---
 src/rollup/types.d.ts | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/rollup/types.d.ts b/src/rollup/types.d.ts
index 9fec100e5fc..189c49e8265 100644
--- a/src/rollup/types.d.ts
+++ b/src/rollup/types.d.ts
@@ -287,7 +287,16 @@ export interface InputOptions {
 	watch?: WatcherOptions;
 }
 
-export type ModuleFormat = 'amd' | 'cjs' | 'system' | 'es' | 'esm' | 'iife' | 'umd';
+export type ModuleFormat =
+	| 'amd'
+	| 'cjs'
+	| 'commonjs'
+	| 'es'
+	| 'esm'
+	| 'iife'
+	| 'module'
+	| 'system'
+	| 'umd';
 
 export type OptionsPaths = Record<string, string> | ((id: string) => string);