Adding syntax highlighting for terraform / hcl

app/assets/javascripts/ide/lib/languages/hcl.js

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See https://github.com/microsoft/monaco-languages/blob/master/LICENSE.md
+ *--------------------------------------------------------------------------------------------*/
+
+/* eslint-disable no-useless-escape */
+/* eslint-disable @gitlab/require-i18n-strings */
+
+const conf = {
+  comments: {
+    lineComment: '//',
+    blockComment: ['/*', '*/'],
+  },
+  brackets: [['{', '}'], ['[', ']'], ['(', ')']],
+  autoClosingPairs: [
+    { open: '{', close: '}' },
+    { open: '[', close: ']' },
+    { open: '(', close: ')' },
+    { open: '"', close: '"', notIn: ['string'] },
+  ],
+  surroundingPairs: [
+    { open: '{', close: '}' },
+    { open: '[', close: ']' },
+    { open: '(', close: ')' },
+    { open: '"', close: '"' },
+  ],
+};
+
+const language = {
+  defaultToken: '',
+  tokenPostfix: '.hcl',
+
+  keywords: [
+    'var',
+    'local',
+    'path',
+    'for_each',
+    'any',
+    'string',
+    'number',
+    'bool',
+    'true',
+    'false',
+    'null',
+    'if ',
+    'else ',
+    'endif ',
+    'for ',
+    'in',
+    'endfor',
+  ],
+
+  operators: [
+    '=',
+    '>=',
+    '<=',
+    '==',
+    '!=',
+    '+',
+    '-',
+    '*',
+    '/',
+    '%',
+    '&&',
+    '||',
+    '!',
+    '<',
+    '>',
+    '?',
+    '...',
+    ':',
+  ],
+
+  symbols: /[=><!~?:&|+\-*\/\^%]+/,
+  escapes: /\\(?:[abfnrtv\\"']|x[0-9A-Fa-f]{1,4}|u[0-9A-Fa-f]{4}|U[0-9A-Fa-f]{8})/,
+  terraformFunctions: /(abs|ceil|floor|log|max|min|pow|signum|chomp|format|formatlist|indent|join|lower|regex|regexall|replace|split|strrev|substr|title|trimspace|upper|chunklist|coalesce|coalescelist|compact|concat|contains|distinct|element|flatten|index|keys|length|list|lookup|map|matchkeys|merge|range|reverse|setintersection|setproduct|setunion|slice|sort|transpose|values|zipmap|base64decode|base64encode|base64gzip|csvdecode|jsondecode|jsonencode|urlencode|yamldecode|yamlencode|abspath|dirname|pathexpand|basename|file|fileexists|fileset|filebase64|templatefile|formatdate|timeadd|timestamp|base64sha256|base64sha512|bcrypt|filebase64sha256|filebase64sha512|filemd5|filemd1|filesha256|filesha512|md5|rsadecrypt|sha1|sha256|sha512|uuid|uuidv5|cidrhost|cidrnetmask|cidrsubnet|tobool|tolist|tomap|tonumber|toset|tostring)/,
+  terraformMainBlocks: /(module|data|terraform|resource|provider|variable|output|locals)/,
+  tokenizer: {
+    root: [
+      // highlight main blocks
+      [
+        /^@terraformMainBlocks([ \t]*)([\w-]+|"[\w-]+"|)([ \t]*)([\w-]+|"[\w-]+"|)([ \t]*)(\{)/,
+        ['type', '', 'string', '', 'string', '', '@brackets'],
+      ],
+      // highlight all the remaining blocks
+      [
+        /(\w+[ \t]+)([ \t]*)([\w-]+|"[\w-]+"|)([ \t]*)([\w-]+|"[\w-]+"|)([ \t]*)(\{)/,
+        ['identifier', '', 'string', '', 'string', '', '@brackets'],
+      ],
+      // highlight block
+      [
+        /(\w+[ \t]+)([ \t]*)([\w-]+|"[\w-]+"|)([ \t]*)([\w-]+|"[\w-]+"|)(=)(\{)/,
+        ['identifier', '', 'string', '', 'operator', '', '@brackets'],
+      ],
+      // terraform general highlight - shared with expressions
+      { include: '@terraform' },
+    ],
+    terraform: [
+      // highlight terraform functions
+      [/@terraformFunctions(\()/, ['type', '@brackets']],
+      // all other words are variables or keywords
+      [
+        /[a-zA-Z_]\w*-*/, // must work with variables such as foo-bar and also with negative numbers
+        {
+          cases: {
+            '@keywords': { token: 'keyword.$0' },
+            '@default': 'variable',
+          },
+        },
+      ],
+      { include: '@whitespace' },
+      { include: '@heredoc' },
+      // delimiters and operators
+      [/[{}()\[\]]/, '@brackets'],
+      [/[<>](?!@symbols)/, '@brackets'],
+      [
+        /@symbols/,
+        {
+          cases: {
+            '@operators': 'operator',
+            '@default': '',
+          },
+        },
+      ],
+      // numbers
+      [/\d*\d+[eE]([\-+]?\d+)?/, 'number.float'],
+      [/\d*\.\d+([eE][\-+]?\d+)?/, 'number.float'],
+      [/\d[\d']*/, 'number'],
+      [/\d/, 'number'],
+      [/[;,.]/, 'delimiter'], // delimiter: after number because of .\d floats
+      // strings
+      [/"/, 'string', '@string'], // this will include expressions
+      [/'/, 'invalid'],
+    ],
+    heredoc: [
+      [
+        /<<[-]*\s*["]?([\w\-]+)["]?/,
+        { token: 'string.heredoc.delimiter', next: '@heredocBody.$1' },
+      ],
+    ],
+    heredocBody: [
+      [
+        /^([\w\-]+)$/,
+        {
+          cases: {
+            '$1==$S2': [
+              {
+                token: 'string.heredoc.delimiter',
+                next: '@popall',
+              },
+            ],
+            '@default': 'string.heredoc',
+          },
+        },
+      ],
+      [/./, 'string.heredoc'],
+    ],
+    whitespace: [
+      [/[ \t\r\n]+/, ''],
+      [/\/\*/, 'comment', '@comment'],
+      [/\/\/.*$/, 'comment'],
+      [/#.*$/, 'comment'],
+    ],
+    comment: [[/[^\/*]+/, 'comment'], [/\*\//, 'comment', '@pop'], [/[\/*]/, 'comment']],
+    string: [
+      [/\$\{/, { token: 'delimiter', next: '@stringExpression' }],
+      [/[^\\"\$]+/, 'string'],
+      [/@escapes/, 'string.escape'],
+      [/\\./, 'string.escape.invalid'],
+      [/"/, 'string', '@popall'],
+    ],
+    stringInsideExpression: [
+      [/[^\\"]+/, 'string'],
+      [/@escapes/, 'string.escape'],
+      [/\\./, 'string.escape.invalid'],
+      [/"/, 'string', '@pop'],
+    ],
+    stringExpression: [
+      [/\}/, { token: 'delimiter', next: '@pop' }],
+      [/"/, 'string', '@stringInsideExpression'],
+      { include: '@terraform' },
+    ],
+  },
+};
+
+export default {
+  id: 'hcl',
+  extensions: ['.tf', '.tfvars', '.hcl'],
+  aliases: ['Terraform', 'tf', 'HCL', 'hcl'],
+  conf,
+  language,
+};

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

 import vue from './vue';
+import hcl from './hcl';
 
-const languages = [vue];
+const languages = [vue, hcl];
 
 export default languages;

changelogs/unreleased/adding-hcl.yml

+---
+title: IDE editor - Adding syntax highlighting for terraform / hcl
+merge_request: 44056
+author:
+type: added