[Tools] Fix line breaks in default JSON serializer (elastic#22653) (e…

…lastic#22801)

* [Tools] Fix line breaks in default JSON serializer

* Add test for not escaped line breaks

src/dev/i18n/__snapshots__/utils.test.js.snap

@@ -1,3 +1,8 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`i18n utils should escape linebreaks 1`] = `"Text with\\\\n\\\\n\\\\nline-breaks and \\\\n\\\\n\\\\n      \\\\n\\\\n\\\\n      "`;
+exports[`i18n utils should not escape linebreaks 1`] = `
+"Text 
+ with
+   line-breaks
+"
+`;

src/dev/i18n/utils.js

@@ -30,7 +30,6 @@ import { promisify } from 'util';
 
 const ESCAPE_LINE_BREAK_REGEX = /(?<!\\)\\\n/g;
 const HTML_LINE_BREAK_REGEX = /[\s]*\n[\s]*/g;
-const LINE_BREAK_REGEX = /\n/g;
 
 export const readFileAsync = promisify(fs.readFile);
 export const writeFileAsync = promisify(fs.writeFile);
@@ -58,7 +57,7 @@ export function isI18nTranslateFunction(node) {
 }
 
 export function formatJSString(string) {
-  return (string || '').replace(ESCAPE_LINE_BREAK_REGEX, '').replace(LINE_BREAK_REGEX, '\\n');
+  return (string || '').replace(ESCAPE_LINE_BREAK_REGEX, '');
 }
 
 export function formatHTMLString(string) {

src/dev/i18n/utils.test.js

@@ -44,18 +44,13 @@ describe('i18n utils', () => {
   test('should remove escaped linebreak', () => {
     expect(formatJSString('Test\\\n str\\\ning')).toEqual('Test string');
   });
-
-  test('should escape linebreaks', () => {
+  test('should not escape linebreaks', () => {
     expect(
-      formatJSString(`Text with
-
-
-line-breaks and \n\n
-      \n\n
-      `)
+      formatJSString(`Text \n with
+   line-breaks
+`)
     ).toMatchSnapshot();
   });
-
   test('should detect i18n translate function call', () => {
     let source = i18nTranslateSources[0];
     let expressionStatementNode = [...traverseNodes(parse(source).program.body)].find(node =>