From 771a975e8bf0177240870ba04f25137d0ad973d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Grzegorz=20=28Greg=29=20Zi=C3=B3=C5=82kowski?=
 <grzegorz@gziolo.pl>
Date: Mon, 24 Feb 2020 17:49:16 +0100
Subject: [PATCH] Scripts: Ensure packages-update works with missing
 dependencies (#20408)

---
 packages/scripts/CHANGELOG.md               |  4 +++
 packages/scripts/scripts/packages-update.js | 30 ++++++++++-----------
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/packages/scripts/CHANGELOG.md b/packages/scripts/CHANGELOG.md
index 3334ccfe8676d5..7471b1cea78397 100644
--- a/packages/scripts/CHANGELOG.md
+++ b/packages/scripts/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Master
 
+### Bug Fixes
+
+- Ensure `packages-update` work when `dependencies` or `devDependencies` are missing in the `package.json` file ([#20408](https://github.com/WordPress/gutenberg/pull/20408)).
+
 ## 7.1.0 (2020-02-10)
 
 ### Bug Fixes
diff --git a/packages/scripts/scripts/packages-update.js b/packages/scripts/scripts/packages-update.js
index 6ebde42cc7b618..5bf8ce531d5822 100644
--- a/packages/scripts/scripts/packages-update.js
+++ b/packages/scripts/scripts/packages-update.js
@@ -15,9 +15,9 @@ function readJSONFile( fileName ) {
 	return JSON.parse( data );
 }
 
-function getWordPressPackages( packageJSON ) {
-	return Object.keys( packageJSON.dependencies )
-		.concat( Object.keys( packageJSON.devDependencies ) )
+function getWordPressPackages( { dependencies = {}, devDependencies = {} } ) {
+	return Object.keys( dependencies )
+		.concat( Object.keys( devDependencies ) )
 		.filter( ( packageName ) =>
 			packageName.startsWith( WORDPRESS_PACKAGES_PREFIX )
 		);
@@ -26,19 +26,17 @@ function getWordPressPackages( packageJSON ) {
 function getPackageVersionDiff( initialPackageJSON, finalPackageJSON ) {
 	const diff = [ 'dependencies', 'devDependencies' ].reduce(
 		( result, keyPackageJSON ) => {
-			return Object.keys( finalPackageJSON[ keyPackageJSON ] ).reduce(
-				( _result, dependency ) => {
-					const initial =
-						initialPackageJSON[ keyPackageJSON ][ dependency ];
-					const final =
-						finalPackageJSON[ keyPackageJSON ][ dependency ];
-					if ( initial !== final ) {
-						_result.push( { dependency, initial, final } );
-					}
-					return _result;
-				},
-				result
-			);
+			return Object.keys(
+				finalPackageJSON[ keyPackageJSON ] || {}
+			).reduce( ( _result, dependency ) => {
+				const initial =
+					initialPackageJSON[ keyPackageJSON ][ dependency ];
+				const final = finalPackageJSON[ keyPackageJSON ][ dependency ];
+				if ( initial !== final ) {
+					_result.push( { dependency, initial, final } );
+				}
+				return _result;
+			}, result );
 		},
 		[]
 	);