Make normalizeLineItems More Robust by Adding Fallback (#4624)

* check for null value and add fallback to displayItem.name

* add test

---------

Co-authored-by: Mayisha <33387139+Mayisha@users.noreply.github.com>
Co-authored-by: daledupreez <dale.du.preez@automattic.com>
Co-authored-by: Wesley Rosa <wesleyjrosa@gmail.com>

Author: 4 people

client/express-checkout/utils/__tests__/normalize.test.js

@@ -94,6 +94,44 @@ describe( 'Express checkout normalization', () => {
 			);
 		} );
 
+		test( 'normalizes line item properly where label is not set', () => {
+			const displayItems = [
+				{
+					name: 'Item 1',
+					label: null,
+					amount: 100,
+				},
+				{
+					name: 'Item 2',
+					label: undefined,
+					amount: 200,
+				},
+				{
+					name: 'Item 3',
+					amount: 300,
+				},
+			];
+
+			const expected = [
+				{
+					name: 'Item 1',
+					amount: 100,
+				},
+				{
+					name: 'Item 2',
+					amount: 200,
+				},
+				{
+					name: 'Item 3',
+					amount: 300,
+				},
+			];
+
+			expect( normalizeLineItems( displayItems ) ).toStrictEqual(
+				expected
+			);
+		} );
+
 		test( 'normalizes discount line item properly', () => {
 			const displayItems = [
 				{

client/express-checkout/utils/normalize.js

@@ -18,7 +18,7 @@ export const normalizeLineItems = ( displayItems ) => {
 		}
 
 		return {
-			name: displayItem.label,
+			name: displayItem.label ?? displayItem.name,
 			amount,
 		};
 	} );