From feb0397b504231f1fd1cbc4500ba28200fa49b96 Mon Sep 17 00:00:00 2001
From: Andrei Glingeanu <andrei.glingeanu@gmail.com>
Date: Fri, 22 Dec 2017 14:02:28 +0200
Subject: [PATCH] feat($i18n): makes the setLocaleData call append to the
 existing locales

---
 i18n/index.js    | 19 ++++++++++++++---
 i18n/test/jed.js | 55 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 3 deletions(-)
 create mode 100644 i18n/test/jed.js

diff --git a/i18n/index.js b/i18n/index.js
index f61c35fa7c650..594078b1562d3 100644
--- a/i18n/index.js
+++ b/i18n/index.js
@@ -13,12 +13,25 @@ let i18n;
  * @param {Object} data Locale data configuration
  */
 export function setLocaleData( data ) {
-	i18n = new Jed( data );
+	i18n = new Jed( {
+		...(i18n ? i18n.options : {}),
+		...data
+	} );
 }
 
 /**
- * Returns the current Jed instance, initializing with a default configuration
- * if not already assigned.
+ * Resets the Jed instance.
+ *
+ * @see http://messageformat.github.io/Jed/
+ *
+ * @param {Object} data Locale data configuration
+ */
+export function resetLocaleData () {
+	i18n = new Jed( { '': {} });
+}
+
+/**
+ * Returns the current Jed instance.
  *
  * @return {Jed} Jed instance
  */
diff --git a/i18n/test/jed.js b/i18n/test/jed.js
new file mode 100644
index 0000000000000..9489eaa48cf8f
--- /dev/null
+++ b/i18n/test/jed.js
@@ -0,0 +1,55 @@
+import { resetLocaleData, setLocaleData, __, getI18n } from '../index';
+
+describe( 'wp.i18n', () => {
+	describe( '.setLocaleData', () => {
+		it('should set locale data', () => {
+			resetLocaleData();
+
+			setLocaleData({
+				domain: 'gutenberg',
+				locale_data: {
+					gutenberg: {
+						"": {
+							domain: 'gutenberg',
+							lang: 'ro_RO'
+						},
+						Demo: ["Demonstrație"],
+						['Gutenberg Team']: ["Echipa Gutenberg"]
+					}
+				}
+			});
+
+			expect( __('Demo') ).toBe( 'Demonstrație' );
+			expect( __('Gutenberg Team') ).toBe( 'Echipa Gutenberg' );
+		});
+
+		it('should preserve local data between multiple .setLocaleData calls', () => {
+			resetLocaleData();
+
+			setLocaleData({
+				domain: 'gutenberg',
+				locale_data: {
+					gutenberg: {
+						"": {
+							domain: 'gutenberg',
+							lang: 'ro_RO'
+						},
+						Demo: ["Demonstrație"]
+					}
+				}
+			});
+
+			setLocaleData({
+				...getI18n().options,
+				locale_data: {
+					gutenberg: {
+						...getI18n().options.locale_data.gutenberg,
+						['Gutenberg Team']: ["Echipa Gutenberg"]
+					}
+				}
+			});
+
+			expect( __('Gutenberg Team') ).toBe( 'Echipa Gutenberg' );
+		} );
+	} );
+} );