Replace re2 with RegExp in timeline and add unit tests

Remove re2 usage and replace it with JavaScript built-in
RegExp object. Also add more unit tests to make sure that
using RegExp has same expressions as using re2 library.

Issue Resolve
#3901

Signed-off-by: Anan Zhuang <ananzh@amazon.com>

Author: ananzh

CHANGELOG.md

@@ -238,6 +238,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - [Multi DataSource] UX enhancement on Data source management stack ([#2521](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2521))
 - [Multi DataSource] UX enhancement on Update stored password modal for Data source management stack ([#2532](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2532))
 - [Monaco editor] Add json worker support ([#3424](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3424))
+- Replace re2 with RegExp in timeline and add unit tests ([#3908](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3908))
 
 ### 🐛 Bug Fixes
 

src/plugins/vis_type_timeline/server/series_functions/label.js

@@ -62,10 +62,8 @@ export default new Chainable('label', {
     const config = args.byName;
     return alter(args, function (eachSeries) {
       if (config.regex) {
-        // not using a standard `import` so that if there's an issue with the re2 native module
-        // that it doesn't prevent OpenSearch Dashboards from starting up and we only have an issue using Timeline labels
-        const RE2 = require('re2');
-        eachSeries.label = eachSeries.label.replace(new RE2(config.regex), config.label);
+        const regex = new RegExp(config.regex);
+        eachSeries.label = eachSeries.label.replace(regex, config.label);
       } else {
         eachSeries.label = config.label;
       }

src/plugins/vis_type_timeline/server/series_functions/label.test.js

@@ -51,4 +51,24 @@ describe('label.js', () => {
       expect(r.output.list[0].label).to.equal('beerative');
     });
   });
+
+  it('can use a regex to capture groups to modify series label', () => {
+    return invoke(fn, [seriesList, 'beer$2', '(N)(egative)']).then((r) => {
+      expect(r.output.list[0].label).to.equal('beeregative');
+    });
+  });
+
+  it('can handle different regex patterns', () => {
+    const seriesListCopy1 = JSON.parse(JSON.stringify(seriesList));
+    const seriesListCopy2 = JSON.parse(JSON.stringify(seriesList));
+
+    return Promise.all([
+      invoke(fn, [seriesListCopy1, 'beer$1 - $2', '(N)(egative)']).then((r) => {
+        expect(r.output.list[0].label).to.equal('beerN - egative');
+      }),
+      invoke(fn, [seriesListCopy2, 'beer$1_$2', '(N)(eg.*)']).then((r) => {
+        expect(r.output.list[0].label).to.equal('beerN_egative');
+      }),
+    ]);
+  });
 });