From 6ea1c38e24ad4101ead05635d8eb626bdb5b36d9 Mon Sep 17 00:00:00 2001
From: Sauli Anto <sauli.anto@gmail.com>
Date: Thu, 3 Oct 2019 12:43:46 +0300
Subject: [PATCH] Fix rest parameters

---
 src/automath.js    | 12 ++++--------
 src/mathediting.js | 10 +++-------
 src/mathui.js      |  5 +----
 3 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/src/automath.js b/src/automath.js
index 30340374c..d4417222e 100644
--- a/src/automath.js
+++ b/src/automath.js
@@ -58,10 +58,7 @@ export default class AutoMath extends Plugin {
 	_mathBetweenPositions( leftPosition, rightPosition ) {
 		const editor = this.editor;
 
-		const mathConfig = {
-			...defaultConfig,
-			...this.editor.config.get( 'math' )
-		};
+		const mathConfig = Object.assign( defaultConfig, this.editor.config.get( 'math' ) );
 
 		const equationRange = new LiveRange( leftPosition, rightPosition );
 		const walker = equationRange.getWalker( { ignoreElementEnd: true } );
@@ -106,10 +103,9 @@ export default class AutoMath extends Plugin {
 				}
 
 				editor.model.change( writer => {
-					const params = {
-						...extractDelimiters( text ),
-						type: mathConfig.outputType,
-					};
+					const params = Object.assign( extractDelimiters( text ), {
+						type: mathConfig.outputType
+					} );
 					const mathElement = writer.createElement( 'mathtex', params );
 
 					editor.model.insertContent( mathElement, insertPosition );
diff --git a/src/mathediting.js b/src/mathediting.js
index e7c1422cd..6c0b10c6c 100644
--- a/src/mathediting.js
+++ b/src/mathediting.js
@@ -36,10 +36,7 @@ export default class MathEditing extends Plugin {
 
 	_defineConverters() {
 		const conversion = this.editor.conversion;
-		const mathConfig = {
-			...defaultConfig,
-			...this.editor.config.get( 'math' )
-		};
+		const mathConfig = Object.assign( defaultConfig, this.editor.config.get( 'math' ) );
 
 		// View -> Model
 		conversion.for( 'upcast' )
@@ -86,10 +83,9 @@ export default class MathEditing extends Plugin {
 				model: ( viewElement, modelWriter ) => {
 					const equation = viewElement.getChild( 0 ).data.trim();
 
-					const params = {
-						...extractDelimiters( equation ),
+					const params = Object.assign( extractDelimiters( equation ), {
 						type: mathConfig.forceOutputType ? mathConfig.outputType : 'span'
-					};
+					} );
 
 					return modelWriter.createElement( 'mathtex', params );
 				}
diff --git a/src/mathui.js b/src/mathui.js
index 09fabf3d2..73300a951 100644
--- a/src/mathui.js
+++ b/src/mathui.js
@@ -59,10 +59,7 @@ export default class MathUI extends Plugin {
 		const editor = this.editor;
 		const mathCommand = editor.commands.get( 'math' );
 
-		const mathConfig = {
-			...defaultConfig,
-			...this.editor.config.get( 'math' )
-		};
+		const mathConfig = Object.assign( defaultConfig, this.editor.config.get( 'math' ) );
 
 		const formView = new MainFormView( editor.locale, mathConfig.engine, mathConfig.enablePreview );