From 95169bbc84cbbc31c268470477bdcff1091cac35 Mon Sep 17 00:00:00 2001
From: Elian Doran <contact@eliandoran.me>
Date: Mon, 24 Nov 2025 18:06:24 +0200
Subject: [PATCH] feat(mime): support KDL (closes #7848)

---
 .../codemirror/src/syntax_highlighting.ts     |  1 +
 packages/commons/src/lib/mime_type.ts         |  1 +
 packages/highlightjs/src/languages/kdl.ts     | 99 +++++++++++++++++++
 .../highlightjs/src/syntax_highlighting.ts    |  1 +
 4 files changed, 102 insertions(+)
 create mode 100644 packages/highlightjs/src/languages/kdl.ts

diff --git a/packages/codemirror/src/syntax_highlighting.ts b/packages/codemirror/src/syntax_highlighting.ts
index 40a0d721d..8d825c080 100644
--- a/packages/codemirror/src/syntax_highlighting.ts
+++ b/packages/codemirror/src/syntax_highlighting.ts
@@ -37,6 +37,7 @@ const byMimeType: Record<string, (() => Promise<StreamParser<unknown> | Language
     "application/sieve": async () => (await import('@codemirror/legacy-modes/mode/sieve')).sieve,
     "application/sparql-query": async () => (await import('@codemirror/legacy-modes/mode/sparql')).sparql,
     "application/typescript": async () => (await import('@codemirror/lang-javascript')).javascript({ typescript: true }),
+    "application/vnd.kdl": null,
     "application/x-aspx": null,
     "application/x-bat": async () => (await import("./languages/batch.js")).batch,
     "application/x-cypher-query": async () => (await import('@codemirror/legacy-modes/mode/cypher')).cypher,
diff --git a/packages/commons/src/lib/mime_type.ts b/packages/commons/src/lib/mime_type.ts
index ba6deafc8..864bf7cae 100644
--- a/packages/commons/src/lib/mime_type.ts
+++ b/packages/commons/src/lib/mime_type.ts
@@ -104,6 +104,7 @@ export const MIME_TYPES_DICT: readonly MimeTypeDefinition[] = Object.freeze([
     { title: "JSX", mime: "text/jsx", mdLanguageCode: "javascript" },
     { title: "Julia", mime: "text/x-julia", mdLanguageCode: "julia" },
     { title: "Kotlin", mime: "text/x-kotlin", mdLanguageCode: "kotlin", default: true },
+    { title: "KDL", mime: "application/vnd.kdl", mdLanguageCode: "kdl" },
     { title: "LaTeX", mime: "text/x-latex", mdLanguageCode: "latex" },
     { title: "LESS", mime: "text/x-less", mdLanguageCode: "less" },
     { title: "LiveScript", mime: "text/x-livescript", mdLanguageCode: "livescript" },
diff --git a/packages/highlightjs/src/languages/kdl.ts b/packages/highlightjs/src/languages/kdl.ts
new file mode 100644
index 000000000..dbf2972c7
--- /dev/null
+++ b/packages/highlightjs/src/languages/kdl.ts
@@ -0,0 +1,99 @@
+// Source: https://github.com/Devasta/highlightjs-kdl/blob/master/src/languages/kdl.js
+import type { HLJSApi, Language } from "highlight.js";
+
+/*
+Language: KDL
+Description: A cuddly document language.
+Author: Daniel Murphy <daniel@devasta.ie>
+Website: https://kdl.dev
+Category: config
+*/
+
+export default function hljsDefineKDL(hljs: HLJSApi): Language {
+    const ESCAPES = {
+        scope: 'char.escape',
+        variants: [
+            { begin: /\\n/ },
+            { begin: /\\r/ },
+            { begin: /\\t/ },
+            { begin: /\\"/ },
+            { begin: /\\\\/ },
+            { begin: /\\b/ },
+            { begin: /\\f/ }
+        ]
+    };
+
+    const LITERALS = [
+        "true",
+        "false",
+        "null"
+    ];
+
+    const STRINGS = {
+        scope: 'string',
+        variants: [
+            {
+                begin: /r(#)+"/,
+                end: /"(#)+/
+            },
+            {
+                begin: /"/,
+                end: /"/
+            }
+        ],
+        contains: [
+            ESCAPES
+        ]
+    };
+
+
+    const COMMENTS = {
+        scope: 'comment',
+        variants: [
+            hljs.C_BLOCK_COMMENT_MODE,
+            hljs.C_LINE_COMMENT_MODE,
+            {
+                begin: /\/-/,
+                end: /\n/
+            }
+        ]
+    };
+
+    const NUMBERS = {
+        scope: 'number',
+        variants: [
+            {
+                begin: /([+-])?0b[_01]*/,
+            },
+            {
+                begin: /([+-])?0o[_0-7]*/,
+            },
+            {
+                begin: /([+-])?0x[_0-9A-Fa-f]*/,
+            },
+            {
+                begin: hljs.C_NUMBER_RE
+            }
+        ]
+    };
+
+    const TYPEANNOTATIONS = {
+        scope: 'type',
+        begin: /\(/,
+        end: /\)/
+    };
+
+    return {
+        name: 'KDL',
+        aliases: [ 'kdl' ],
+        contains: [
+            STRINGS,
+            COMMENTS,
+            NUMBERS,
+            TYPEANNOTATIONS
+        ],
+        keywords: {
+            literal: LITERALS
+        }
+    };
+}
diff --git a/packages/highlightjs/src/syntax_highlighting.ts b/packages/highlightjs/src/syntax_highlighting.ts
index 1970e1b40..735657873 100644
--- a/packages/highlightjs/src/syntax_highlighting.ts
+++ b/packages/highlightjs/src/syntax_highlighting.ts
@@ -17,6 +17,7 @@ export const byMimeType: MimeRecord = {
     "application/sieve": null,
     "application/sparql-query": null,
     "application/typescript": () => import("highlight.js/lib/languages/typescript"),
+    "application/vnd.kdl": () => import("./languages/kdl.js"),
     "application/x-aspx": null,
     "application/x-bat": () => import("highlight.js/lib/languages/dos"),
     "application/x-cypher-query": () => import("highlightjs-cypher"),