Use GitHub theme for Web IDE as default

Pygments uses GitHub theme as default. Use it in the Web IDE too.

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

+const BOLD = 'bold';
+const ITALIC = 'italic';
+const BOLD_ITALIC = 'bold italic';
+const UNDERLINE = 'underline';
+
 export default {
   base: 'vs',
-  inherit: true,
-  rules: [],
+  inherit: false,
+  rules: [
+    // Standard theme defaults and overrides based on VS theme
+    // https://github.com/Microsoft/vscode/blob/master/src/vs/editor/standalone/common/themes.ts
+    // License: MIT (https://github.com/microsoft/vscode/blob/master/LICENSE.txt)
+    { token: '', foreground: '2e2e2e', background: 'ffffff' },
+    { token: 'keyword.css', fontStyle: BOLD, foreground: '999999' },
+    { token: 'keyword.less', fontStyle: BOLD, foreground: '999999' },
+    { token: 'keyword.scss', fontStyle: BOLD, foreground: '999999' },
+    { token: 'keyword.md', fontStyle: BOLD, foreground: '800080' },
+
+    { token: 'variable', foreground: '008080' },
+    { token: 'variable.md', foreground: 'dd1144' },
+    { token: 'variable.predefined', foreground: '008080' },
+    { token: 'number', foreground: '009999' },
+    { token: 'number.hex', foreground: '3030c0' },
+
+    { token: 'type.identifier.ts', foreground: '445588', fontStyle: BOLD },
+    { token: 'type.identifier.swift', foreground: '445588', fontStyle: BOLD },
+    { token: 'type.identifier.kt', foreground: '445588', fontStyle: BOLD },
+    { token: 'type.identifier.perl', foreground: '2e2e2e', fontStyle: BOLD },
+
+    { token: 'tag', foreground: '000080' },
+    { token: 'tag.class', foreground: '445588', fontStyle: BOLD },
+    { token: 'tag.css', foreground: '445588', fontStyle: BOLD },
+    { token: 'tag.less', foreground: '445588', fontStyle: BOLD },
+    { token: 'tag.scss', foreground: '445588', fontStyle: BOLD },
+    { token: 'tag.id.jade', foreground: '445588' },
+    { token: 'tag.class.jade', foreground: '445588' },
+    { token: 'meta.scss', foreground: '800000' },
+    { token: 'metatag', foreground: 'e00000' },
+    { token: 'metatag.content.html', foreground: 'e00000' },
+    { token: 'metatag.html', foreground: '808080' },
+    { token: 'metatag.xml', foreground: '808080' },
+    { token: 'metatag.php', fontStyle: BOLD },
+
+    { token: 'key', foreground: '863b00' },
+    { token: 'key.ini', foreground: '008080' },
+    { token: 'string.key.json', foreground: '2e2e2e' },
+    { token: 'string.value.json', foreground: 'dd1144' },
+    { token: 'string.link.md', foreground: 'aa0000' },
+
+    { token: 'attribute.name', foreground: '008080' },
+    { token: 'attribute.name.css', foreground: '2e2e2e' },
+    { token: 'attribute.name.json', foreground: '2e2e2e' },
+    { token: 'attribute.name.scss', foreground: '2e2e2e' },
+    { token: 'attribute.name.less', foreground: '2e2e2e' },
+    { token: 'attribute.value', foreground: 'dd1144' },
+    { token: 'attribute.value.css', foreground: '0086b3' },
+    { token: 'attribute.value.hex', foreground: '0086b3' },
+    { token: 'attribute.value.number', foreground: '009999' },
+    { token: 'attribute.value.unit', foreground: '009999' },
+    { token: 'attribute.value.xml', foreground: 'dd1144' },
+    { token: 'attribute.value.html', foreground: 'dd1144' },
+    { token: 'attribute.value.md', foreground: 'aa0000' },
+
+    { token: 'string', foreground: 'dd1144' },
+    { token: 'string.target', foreground: 'aa0000' },
+    { token: 'string.sql', foreground: 'dd1144' },
+
+    { token: 'keyword.flow', foreground: '2e2e2e', fontStyle: BOLD },
+    { token: 'keyword.st', foreground: '445588', fontStyle: BOLD },
+    { token: 'variable.st', foreground: '445588', fontStyle: BOLD },
+    { token: 'type.st', foreground: '445588', fontStyle: BOLD },
+
+    { token: 'operator.scss', foreground: '666666' },
+    { token: 'operator.sql', foreground: '2e2e2e', fontStyle: BOLD },
+    { token: 'operator.swift', foreground: '666666' },
+    { token: 'predefined.sql', foreground: '2e2e2e', fontStyle: BOLD },
+
+    // GitHub theme based on https://github.com/brijeshb42/monaco-themes/blob/master/themes/GitHub.json
+    // Customized for Web IDE
+    // License: MIT (https://github.com/brijeshb42/monaco-themes/blob/master/LICENSE)
+    { token: 'comment', foreground: '999988', fontStyle: ITALIC },
+    { token: 'comment.block.preprocessor', foreground: '999999', fontStyle: BOLD },
+    { token: 'comment.documentation', foreground: '999999', fontStyle: BOLD_ITALIC },
+    { token: 'comment.block.documentation', foreground: '999999', fontStyle: BOLD_ITALIC },
+    { token: 'invalid.illegal', foreground: 'aa0000', background: 'e3d2d2' },
+    { token: 'keyword', fontStyle: BOLD, foreground: '2e2e2e' },
+    { token: 'storage', fontStyle: BOLD },
+    { token: 'keyword.operator', fontStyle: BOLD },
+    { token: 'constant.language', fontStyle: BOLD },
+    { token: 'support.constant', fontStyle: BOLD },
+    { token: 'storage.type', foreground: '445588', fontStyle: BOLD },
+    { token: 'support.type', foreground: '445588', fontStyle: BOLD },
+    { token: 'entity.other.attribute-name', foreground: '008080' },
+    { token: 'variable.other', foreground: '0086b3' },
+    { token: 'variable.language', foreground: '999999' },
+    { token: 'entity.name.type', foreground: '445588', fontStyle: BOLD },
+    { token: 'entity.other.inherited-class', foreground: '445588', fontStyle: BOLD },
+    { token: 'support.class', foreground: '445588', fontStyle: BOLD },
+    { token: 'variable.other.constant', foreground: '008080' },
+    { token: 'constant.character.entity', foreground: '800080' },
+    { token: 'entity.name.exception', foreground: 'aa0000' },
+    { token: 'entity.name.function', foreground: 'aa0000' },
+    { token: 'support.function', foreground: 'aa0000' },
+    { token: 'keyword.other.name-of-parameter', foreground: 'aa0000' },
+    { token: 'entity.name.section', foreground: '666666' },
+    { token: 'entity.name.tag', foreground: '000080' },
+    { token: 'variable.parameter', foreground: '008080' },
+    { token: 'support.variable', foreground: '008080' },
+    { token: 'constant.numeric', foreground: '009999' },
+    { token: 'constant.other', foreground: '009999' },
+    { token: 'constant.character', foreground: 'dd1144' },
+    { token: 'string.regexp', foreground: '009926' },
+    { token: 'constant.other.symbol', foreground: '990073' },
+    { token: 'punctuation', fontStyle: BOLD },
+    { token: 'markup.deleted', foreground: '000000', background: 'ffdddd' },
+    { token: 'markup.italic', fontStyle: ITALIC },
+    { token: 'markup.error', foreground: 'aa0000' },
+    { token: 'markup.heading.1', foreground: '999999' },
+    { token: 'markup.inserted', foreground: '000000', background: 'ddffdd' },
+    { token: 'markup.output', foreground: '808080' },
+    { token: 'markup.raw', foreground: '808080' },
+    { token: 'markup.prompt', foreground: '666666' },
+    { token: 'markup.bold', fontStyle: BOLD },
+    { token: 'markup.heading', foreground: '999999' },
+    { token: 'markup.traceback', foreground: 'aa0000' },
+    { token: 'markup.underline', fontStyle: UNDERLINE },
+    { token: 'meta.diff.range', foreground: '999999', background: 'eaf2f5' },
+    { token: 'meta.diff.index', foreground: '999999', background: 'eaf2f5' },
+    { token: 'meta.separator', foreground: '999999', background: 'eaf2f5' },
+    { token: 'meta.diff.header.from-file', foreground: '999999', background: 'ffdddd' },
+    { token: 'meta.diff.header.to-file', foreground: '999999', background: 'ddffdd' },
+    { token: 'meta.link', foreground: '4183c4' },
+  ],
   colors: {
-    'editorLineNumber.foreground': '#CCCCCC',
-    'diffEditor.insertedTextBackground': '#A0F5B420',
-    'diffEditor.removedTextBackground': '#f9d7dc20',
+    'editor.foreground': '#2e2e2e',
     'editor.selectionBackground': '#aad6f8',
+    'editor.lineHighlightBackground': '#fffeeb',
+    'editorCursor.foreground': '#666666',
+    'editorWhitespace.foreground': '#bbbbbb',
+
+    'editorLineNumber.foreground': '#cccccc',
+    'diffEditor.insertedTextBackground': '#a0f5b420',
+    'diffEditor.removedTextBackground': '#f9d7dc20',
     'editorIndentGuide.activeBackground': '#cccccc',
   },
 };

changelogs/unreleased/201931-white-syntax-highlighting-theme-for-web-ide.yml

+---
+title: Fix White syntax highlighting theme in Monaco to closely match the Pygments theme.
+merge_request: 25966
+author:
+type: fixed