Support Go

README.md

@@ -176,7 +176,7 @@ Available themes: Aurora X, Dracula, GitHub Dark, GitHub Light, Monokai, Nord, O
 
 ## Languages
 
-`apache`, `css`, `diff`, `dockerfile`, `ejs`, `env`, `html`, `http`, `js`, `json`, `jsx`, `markdown`, `mermaid`, `nginx`, `plaintext`, `python`, `scheme`, `shell`, `sql`, `svelte`, `toml`, `ts`, `tsrx`, `tsx`, `vue`, and `yaml`.
+`apache`, `css`, `diff`, `dockerfile`, `ejs`, `env`, `go`, `html`, `http`, `js`, `json`, `jsx`, `markdown`, `mermaid`, `nginx`, `plaintext`, `python`, `scheme`, `shell`, `sql`, `svelte`, `toml`, `ts`, `tsrx`, `tsx`, `vue`, and `yaml`.
 
 Each language is available from `@tanstack/highlight/languages/<name>`. The aggregate `@tanstack/highlight/languages` entry can tree-shake, while direct subpaths make isolation explicit.
 
@@ -199,7 +199,7 @@ Local browser bundles, minified with esbuild and compressed independently:
 | Core + TSX | 9.3 KB | 3.9 KB | 3.5 KB |
 | Octane MDX + TypeScript | 12.5 KB | 4.9 KB | 4.5 KB |
 | Nine-language docs set | 15.3 KB | 5.8 KB | 5.3 KB |
-| All 25 languages | 22.2 KB | 8.0 KB | 7.2 KB |
+| All 27 languages | 24.0 KB | 8.6 KB | 7.7 KB |
 
 On 80 real JavaScript/TypeScript/JSX/TSX TanStack docs fixtures repeated across 5,040 blocks:
 

docs/guides/performance.md

@@ -16,7 +16,7 @@ Small and fast are product constraints, not README adjectives. The repository me
 | TSX | TSX | 3.86 KB | 4.1 KB |
 | Octane | TypeScript plus Octane MDX adapter | 4.93 KB | 5.2 KB |
 | Docs | CSS, HTML, JS, JSON, JSX, Markdown, Shell, TS, TSX | 5.83 KB | 6.1 KB |
-| All | All 25 definitions | 7.96 KB | 8.3 KB |
+| All | All 27 definitions | 8.60 KB | 8.9 KB |
 
 Selective profiles are the primary metric. The all-language profile exists to prevent convenience-entry growth from becoming invisible.
 

docs/language-support.md

@@ -16,6 +16,7 @@ Every language is an isolated definition imported from `@tanstack/highlight/lang
 | Dockerfile | `dockerfile` | `docker` | Common directives, variables, commands |
 | EJS | `ejs` | - | HTML plus optional JavaScript delegation |
 | Env | `env` | `dotenv` | Properties, values, comments |
+| Go | `go` | `golang` | Raw strings, runes, comments, declarations |
 | HTML | `html` | `htm`, `xml`, `angular-html` | Optional JavaScript/TypeScript and CSS delegation |
 | HTTP | `http` | - | Methods, headers, protocol, paths |
 | JavaScript | `js` | `javascript`, `mjs`, `cjs`, `js-vue` | Templates, interpolation, regex literals |

docs/reference/default-entry.md

@@ -43,7 +43,7 @@ Returns the canonical registered language name for a name or alias. Names are tr
 function listLanguages(): Array<HighlightLanguage>
 ```
 
-Returns the 25 canonical language names registered in `defaultHighlighter`.
+Returns the 27 canonical language names registered in `defaultHighlighter`.
 
 ### `tokenize`
 

docs/reference/languages.md

@@ -27,6 +27,7 @@ const highlighter = createHighlighter({
 | `dockerfile` | `@tanstack/highlight/languages/dockerfile` | `docker` |
 | `ejs` | `@tanstack/highlight/languages/ejs` | None |
 | `env` | `@tanstack/highlight/languages/env` | `dotenv` |
+| `go` | `@tanstack/highlight/languages/go` | `golang` |
 | `html` | `@tanstack/highlight/languages/html` | `htm`, `xml`, `angular-html` |
 | `http` | `@tanstack/highlight/languages/http` | None |
 | `js` | `@tanstack/highlight/languages/js` | `javascript`, `mjs`, `cjs`, `js-vue` |
@@ -48,6 +49,6 @@ const highlighter = createHighlighter({
 | `vue` | `@tanstack/highlight/languages/vue` | None |
 | `yaml` | `@tanstack/highlight/languages/yaml` | `yml` |
 
-`@tanstack/highlight/languages` re-exports `apache`, `css`, `diff`, `dockerfile`, `ejs`, `env`, `html`, `http`, `js`, `json`, `jsx`, `markdown`, `mermaid`, `nginx`, `plaintext`, `python`, `scheme`, `shell`, `sql`, `svelte`, `toml`, `ts`, `tsrx`, `tsx`, `vue`, and `yaml`. The barrel is convenient but individual subpaths make bundle intent explicit.
+`@tanstack/highlight/languages` re-exports `apache`, `css`, `diff`, `dockerfile`, `ejs`, `env`, `go`, `html`, `http`, `js`, `json`, `jsx`, `markdown`, `mermaid`, `nginx`, `plaintext`, `python`, `scheme`, `shell`, `sql`, `svelte`, `toml`, `ts`, `tsrx`, `tsx`, `vue`, and `yaml`. The barrel is convenient but individual subpaths make bundle intent explicit.
 
 See the [language support matrix](../language-support) for the context-aware behavior and current scope of each registration.

docs/test-strategy.md

@@ -27,7 +27,7 @@ The suite protects the package's actual product boundary: valid code commonly pu
 | TSX | TSX | 4.1 KB |
 | Octane | TypeScript plus Octane MDX adapter | 5.2 KB |
 | Docs | CSS, HTML, JS, JSON, JSX, Markdown, Shell, TS, TSX | 6.1 KB |
-| All | All 25 definitions | 8.3 KB |
+| All | All 27 definitions | 8.9 KB |
 
 The selective profiles are the primary product metric. The all-language profile protects the convenience entry from unbounded growth.
 

scripts/language-utils.mjs

@@ -8,6 +8,7 @@ export const supportedLanguages = [
   'dockerfile',
   'ejs',
   'env',
+  'go',
   'html',
   'http',
   'js',
@@ -39,6 +40,7 @@ const aliases = {
   cmd: 'shell',
   console: 'shell',
   dotenv: 'env',
+  golang: 'go',
   htm: 'html',
   javascript: 'js',
   'js-vue': 'js',

scripts/measure-size.mjs

@@ -51,7 +51,7 @@ const profiles = {
       import { defaultHighlighter } from './src/index.ts'
       globalThis.highlighter = defaultHighlighter
     `,
-    limits: { minified: 23_000, gzip: 8_300, brotli: 7_500 },
+    limits: { minified: 24_500, gzip: 8_900, brotli: 8_000 },
   },
 }
 

src/index.ts

@@ -11,6 +11,7 @@ import { diff } from './languages/diff.js'
 import { dockerfile } from './languages/dockerfile.js'
 import { ejs } from './languages/ejs.js'
 import { env } from './languages/env.js'
+import { go } from './languages/go.js'
 import { html } from './languages/html.js'
 import { http } from './languages/http.js'
 import { js } from './languages/js.js'
@@ -39,6 +40,7 @@ export type HighlightLanguage =
   | 'dockerfile'
   | 'ejs'
   | 'env'
+  | 'go'
   | 'html'
   | 'http'
   | 'js'
@@ -107,6 +109,7 @@ export const allLanguages = [
   dockerfile,
   ejs,
   env,
+  go,
   html,
   http,
   js,

src/languages/go.ts

@@ -0,0 +1,40 @@
+import { defineLanguage } from '../core.js'
+import { patternTokenizer } from '../internal/patterns.js'
+
+export const go = defineLanguage({
+  name: 'go',
+  aliases: ['golang'],
+  tokenize: patternTokenizer([
+    {
+      className: (match) =>
+        match[0].startsWith('/') ? 'comment' : 'string',
+      regex:
+        /\/\/[^\n]*|\/\*[\s\S]*?\*\/|`[\s\S]*?`|"(?:\\.|[^"\\\n])*"|'(?:\\.|[^'\\\n])*'/g,
+    },
+    {
+      className: 'keyword',
+      regex:
+        /\b(?:break|case|chan|const|continue|default|defer|else|fallthrough|for|func|go|goto|if|import|interface|map|package|range|return|select|struct|switch|type|var)\b/g,
+    },
+    { className: 'literal', regex: /\b(?:false|iota|nil|true)\b/g },
+    { className: 'type', regex: /\btype\s+([A-Za-z_]\w*)/g, group: 1 },
+    {
+      className: 'type',
+      regex:
+        /\b(?:any|bool|byte|comparable|complex64|complex128|error|float32|float64|int|int8|int16|int32|int64|rune|string|uint|uint8|uint16|uint32|uint64|uintptr)\b/g,
+    },
+    { className: 'function', regex: /\b[A-Za-z_]\w*(?=\s*\()/g },
+    {
+      className: 'number',
+      regex:
+        /(?:^|[^\w.])((?:0[bB]_?[01](?:_?[01])*|0[oO]_?[0-7](?:_?[0-7])*|0[xX](?:(?:_?[\da-fA-F](?:_?[\da-fA-F])*(?:\.(?:[\da-fA-F](?:_?[\da-fA-F])*)?)?|\.[\da-fA-F](?:_?[\da-fA-F])*)[pP][+-]?\d(?:_?\d)*|_?[\da-fA-F](?:_?[\da-fA-F])*)|\d(?:_?\d)*\.(?:\d(?:_?\d)*)?(?:[eE][+-]?\d(?:_?\d)*)?|\d(?:_?\d)*[eE][+-]?\d(?:_?\d)*|\.\d(?:_?\d)*(?:[eE][+-]?\d(?:_?\d)*)?|\d(?:_?\d)*)(?:i)?)(?![\w.])/g,
+      group: 1,
+    },
+    { className: 'property', regex: /\.\s*([A-Za-z_]\w*)/g, group: 1 },
+    {
+      className: 'operator',
+      regex:
+        /\.\.\.|<<=?|>>=?|&\^=?|:=|<-|\+\+|--|==|!=|<=|>=|&&|\|\||[+\-*/%&|^!<>=~]=?/g,
+    },
+  ]),
+})

src/languages/index.ts

@@ -4,6 +4,7 @@ export { diff } from './diff.js'
 export { dockerfile } from './dockerfile.js'
 export { ejs } from './ejs.js'
 export { env } from './env.js'
+export { go } from './go.js'
 export { html } from './html.js'
 export { http } from './http.js'
 export { js } from './js.js'

test/fixtures.ts

@@ -29,6 +29,35 @@ export function Counter() @{
       'th-number',
     ],
   },
+  {
+    lang: 'golang',
+    normalized: 'go',
+    code: `package main
+
+import "fmt"
+
+type Greeter struct {
+  Name string
+}
+
+func (g Greeter) Greet() {
+  count := 2
+  url := \`https://go.dev\`
+  initial := 'G'
+  fmt.Println(url, initial, g.Name, count, true) // greet
+}`,
+    expectedClasses: [
+      'th-keyword',
+      'th-string',
+      'th-type',
+      'th-function',
+      'th-property',
+      'th-number',
+      'th-literal',
+      'th-comment',
+      'th-operator',
+    ],
+  },
   {
     lang: 'tsx',
     normalized: 'tsx',

test/highlight.contract.test.ts

@@ -28,11 +28,17 @@ describe('language inventory', () => {
 
   it('lists the normalized support targets once', () => {
     const languages = listLanguages()
+    const fixtureLanguages = new Set(
+      languageFixtures.map((fixture) => fixture.normalized),
+    )
     expect(new Set(languages).size).toBe(languages.length)
 
     for (const fixture of languageFixtures) {
       expect(languages).toContain(fixture.normalized)
     }
+    for (const language of languages) {
+      expect(fixtureLanguages, `missing representative fixture for ${language}`).toContain(language)
+    }
   })
 })
 
@@ -82,6 +88,7 @@ describe('output contract', () => {
   it('keeps comment markers inside strings and quotes inside comments', () => {
     const cases = [
       ['ts', `const url = "https://example.com" // "comment"`],
+      ['go', `url := "https://go.dev" // "comment"`],
       ['python', `value = "# not a comment" # "comment"`],
       ['shell', `echo "# not a comment" # "comment"`],
       ['yaml', `url: "https://example.com/#hash" # "comment"`],

test/real-doc-fixtures.test.ts

@@ -11,12 +11,14 @@ type DocFixture = {
 }
 
 const fixtures = fixtureData.fixtures as Array<DocFixture>
+const languagesWithoutRealDocFixtures = new Set(['go'])
 
 describe('real TanStack docs fixtures', () => {
-  it('covers every normalized language target with sampled docs code', () => {
+  it('covers normalized language targets available in TanStack docs', () => {
     const fixtureLanguages = new Set(fixtures.map((fixture) => fixture.lang))
 
     for (const language of listLanguages()) {
+      if (languagesWithoutRealDocFixtures.has(language)) continue
       expect(fixtureLanguages, `missing real docs fixture for ${language}`).toContain(language)
     }
   })
@@ -53,8 +55,9 @@ describe('real TanStack docs fixtures', () => {
       }
     }
 
+    const fixtureLanguages = new Set(fixtures.map((fixture) => fixture.lang))
     for (const language of listLanguages()) {
-      if (language === 'plaintext') continue
+      if (language === 'plaintext' || !fixtureLanguages.has(language)) continue
       expect(highlightedLanguages, `${language} should highlight at least one real docs fixture`).toContain(language)
     }
   })

test/regressions.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it } from 'vitest'
 import { createHighlighter } from '../src/core'
 import { css } from '../src/languages/css'
 import { dockerfile } from '../src/languages/dockerfile'
+import { go } from '../src/languages/go'
 import { html } from '../src/languages/html'
 import { http } from '../src/languages/http'
 import { js } from '../src/languages/js'
@@ -19,6 +20,7 @@ const highlighter = createHighlighter({
   languages: [
     css,
     dockerfile,
+    go,
     html,
     http,
     js,
@@ -305,6 +307,46 @@ export function View() @{ <p>Ready</p> }`,
 })
 
 describe('docs language regressions', () => {
+  it('handles Go raw strings, runes, and numeric forms', () => {
+    const numbers = [
+      '0b1010',
+      '0o755',
+      '0x1.fp2',
+      '1.',
+      '1.e2',
+      '1.e2i',
+      '.5',
+      '.5i',
+      '.5e2',
+      '.5e2i',
+      '1e2',
+      '1e2i',
+      '0x1.p2',
+      '0x.8p2',
+      '0x_1p2',
+      '0x1.p2i',
+      '1_000.5e-2i',
+    ]
+    const result = highlighter.tokenize(
+      [
+        'raw := `https://go.dev/a//b`',
+        "runeValue := '\\n'",
+        `values := []complex128{${numbers.join(', ')}}`,
+        '// done',
+      ].join('\n'),
+      { lang: 'go' },
+    )
+
+    expect(exactClassesFor(result, '`https://go.dev/a//b`')).toEqual(['string'])
+    expect(exactClassesFor(result, "'\\n'")).toEqual(['string'])
+    expect(exactClassesFor(result, 'complex128')).toEqual(['type'])
+    for (const number of numbers) {
+      expect(exactClassesFor(result, number), number).toEqual(['number'])
+    }
+    expect(exactClassesFor(result, '// done')).toEqual(['comment'])
+    expect(reconstruct(result)).toBe(result.code)
+  })
+
   it('keeps Python triple strings together and highlights literals and numbers', () => {
     const result = highlighter.tokenize(
       'text = """hello\nworld"""\nempty = None\nenabled = True\ncount = 42',