Add Solarized Dark syntax highlighting theme

Add support for Solarized Dark syntax highlighting theme for the Web IDE

app/assets/javascripts/ide/lib/themes/index.js

 import white from './white';
 import dark from './dark';
+import monokai from './monokai';
+import solarizedDark from './solarized_dark';
 
 export const themes = [
   {
@@ -10,6 +12,14 @@ export const themes = [
     name: 'dark',
     data: dark,
   },
+  {
+    name: 'solarized-dark',
+    data: solarizedDark,
+  },
+  {
+    name: 'monokai',
+    data: monokai,
+  },
 ];
 
 export const DEFAULT_THEME = 'white';

app/assets/javascripts/ide/lib/themes/monokai.js

+/*
+
+https://github.com/brijeshb42/monaco-themes/blob/master/themes/Tomorrow-Night.json
+
+The MIT License (MIT)
+
+Copyright (c) Brijesh Bittu
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+*/
+
+export default {
+  base: 'vs-dark',
+  inherit: true,
+  rules: [
+    {
+      foreground: '75715e',
+      token: 'comment',
+    },
+    {
+      foreground: 'e6db74',
+      token: 'string',
+    },
+    {
+      foreground: 'ae81ff',
+      token: 'constant.numeric',
+    },
+    {
+      foreground: 'ae81ff',
+      token: 'constant.language',
+    },
+    {
+      foreground: 'ae81ff',
+      token: 'constant.character',
+    },
+    {
+      foreground: 'ae81ff',
+      token: 'constant.other',
+    },
+    {
+      foreground: 'f92672',
+      token: 'keyword',
+    },
+    {
+      foreground: 'f92672',
+      token: 'storage',
+    },
+    {
+      foreground: '66d9ef',
+      fontStyle: 'italic',
+      token: 'storage.type',
+    },
+    {
+      foreground: 'a6e22e',
+      fontStyle: 'underline',
+      token: 'entity.name.class',
+    },
+    {
+      foreground: 'a6e22e',
+      // eslint-disable-next-line @gitlab/require-i18n-strings
+      fontStyle: 'italic underline',
+      token: 'entity.other.inherited-class',
+    },
+    {
+      foreground: 'a6e22e',
+      token: 'entity.name.function',
+    },
+    {
+      foreground: 'fd971f',
+      fontStyle: 'italic',
+      token: 'variable.parameter',
+    },
+    {
+      foreground: 'f92672',
+      token: 'entity.name.tag',
+    },
+    {
+      foreground: 'a6e22e',
+      token: 'entity.other.attribute-name',
+    },
+    {
+      foreground: '66d9ef',
+      token: 'support.function',
+    },
+    {
+      foreground: '66d9ef',
+      token: 'support.constant',
+    },
+    {
+      foreground: '66d9ef',
+      fontStyle: 'italic',
+      token: 'support.type',
+    },
+    {
+      foreground: '66d9ef',
+      fontStyle: 'italic',
+      token: 'support.class',
+    },
+    {
+      foreground: 'f8f8f0',
+      background: 'f92672',
+      token: 'invalid',
+    },
+    {
+      foreground: 'f8f8f0',
+      background: 'ae81ff',
+      token: 'invalid.deprecated',
+    },
+    {
+      foreground: 'cfcfc2',
+      token: 'meta.structure.dictionary.json string.quoted.double.json',
+    },
+    {
+      foreground: '75715e',
+      token: 'meta.diff',
+    },
+    {
+      foreground: '75715e',
+      token: 'meta.diff.header',
+    },
+    {
+      foreground: 'f92672',
+      token: 'markup.deleted',
+    },
+    {
+      foreground: 'a6e22e',
+      token: 'markup.inserted',
+    },
+    {
+      foreground: 'e6db74',
+      token: 'markup.changed',
+    },
+    {
+      foreground: 'ae81ffa0',
+      token: 'constant.numeric.line-number.find-in-files - match',
+    },
+    {
+      foreground: 'e6db74',
+      token: 'entity.name.filename.find-in-files',
+    },
+  ],
+  colors: {
+    'editor.foreground': '#F8F8F2',
+    'editor.background': '#272822',
+    'editor.selectionBackground': '#49483E',
+    'editor.lineHighlightBackground': '#3E3D32',
+    'editorCursor.foreground': '#F8F8F0',
+    'editorWhitespace.foreground': '#3B3A32',
+    'editorIndentGuide.activeBackground': '#9D550FB0',
+    'editor.selectionHighlightBorder': '#222218',
+  },
+};

changelogs/unreleased/201927-solarized-dark.yml

+---
+title: Monokai and Solarized Dark syntax highlighting theme for Web IDE
+merge_request: 30931
+author:
+type: added