chore(lint): enable TypeScript linting in frontend

oxlint now includes support for TypeScript-aware linting by using
the oxlint-tsgolint package. While this increases the chance of
finding bugs early, it requires a few changes to the TypeScript
configuration, especially the explicit declaration of CSS imports
and changing the moduleResolution to bundler mode.

Signed-off-by: Erik Michelson <github@erik.michelson.eu>

frontend/.oxlintrc.json

@@ -25,5 +25,10 @@
   "env": {
     "browser": true,
     "jest": true
+  },
+  "options": {
+    "typeAware": true,
+    "typeCheck": true,
+    "maxWarnings": 0
   }
 }

frontend/src/external-types/css/index.d.ts

@@ -0,0 +1,18 @@
+/*
+ * SPDX-FileCopyrightText: 2026 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+declare module '*.css'
+declare module '*.scss'
+
+declare module '*.module.css' {
+  const classes: Record<string, string>
+  export default classes
+}
+
+declare module '*.module.scss' {
+  const classes: Record<string, string>
+  export default classes
+}

frontend/tsconfig.json

@@ -13,7 +13,7 @@
     "noEmit": true,
     "esModuleInterop": true,
     "module": "esnext",
-    "moduleResolution": "node",
+    "moduleResolution": "bundler",
     "resolveJsonModule": true,
     "isolatedModules": true,
     "jsx": "preserve",
@@ -30,6 +30,7 @@
     ]
   },
   "include": [
+    "src/external-types/css/index.d.ts",
     "src/external-types/images/index.d.ts",
     "next-env.d.ts",
     "**/*.ts",

package.json

@@ -48,7 +48,8 @@
   "devDependencies": {
     "dotenv-cli": "11.0.0",
     "oxfmt": "0.23.0",
-    "oxlint": "1.38.0",
+    "oxlint": "1.63.0",
+    "oxlint-tsgolint": "0.22.1",
     "turbo": "2.8.13"
   }
 }

yarn.lock

@@ -4730,6 +4730,48 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@oxlint-tsgolint/darwin-arm64@npm:0.22.1":
+  version: 0.22.1
+  resolution: "@oxlint-tsgolint/darwin-arm64@npm:0.22.1"
+  conditions: os=darwin & cpu=arm64
+  languageName: node
+  linkType: hard
+
+"@oxlint-tsgolint/darwin-x64@npm:0.22.1":
+  version: 0.22.1
+  resolution: "@oxlint-tsgolint/darwin-x64@npm:0.22.1"
+  conditions: os=darwin & cpu=x64
+  languageName: node
+  linkType: hard
+
+"@oxlint-tsgolint/linux-arm64@npm:0.22.1":
+  version: 0.22.1
+  resolution: "@oxlint-tsgolint/linux-arm64@npm:0.22.1"
+  conditions: os=linux & cpu=arm64
+  languageName: node
+  linkType: hard
+
+"@oxlint-tsgolint/linux-x64@npm:0.22.1":
+  version: 0.22.1
+  resolution: "@oxlint-tsgolint/linux-x64@npm:0.22.1"
+  conditions: os=linux & cpu=x64
+  languageName: node
+  linkType: hard
+
+"@oxlint-tsgolint/win32-arm64@npm:0.22.1":
+  version: 0.22.1
+  resolution: "@oxlint-tsgolint/win32-arm64@npm:0.22.1"
+  conditions: os=win32 & cpu=arm64
+  languageName: node
+  linkType: hard
+
+"@oxlint-tsgolint/win32-x64@npm:0.22.1":
+  version: 0.22.1
+  resolution: "@oxlint-tsgolint/win32-x64@npm:0.22.1"
+  conditions: os=win32 & cpu=x64
+  languageName: node
+  linkType: hard
+
 "@oxlint/darwin-arm64@npm:1.38.0":
   version: 1.38.0
   resolution: "@oxlint/darwin-arm64@npm:1.38.0"
@@ -10984,6 +11026,7 @@ __metadata:
     dotenv-cli: "npm:11.0.0"
     oxfmt: "npm:0.23.0"
     oxlint: "npm:1.38.0"
+    oxlint-tsgolint: "npm:0.22.1"
     turbo: "npm:2.8.13"
   languageName: unknown
   linkType: soft
@@ -14327,6 +14370,35 @@ __metadata:
   languageName: node
   linkType: hard
 
+"oxlint-tsgolint@npm:0.22.1":
+  version: 0.22.1
+  resolution: "oxlint-tsgolint@npm:0.22.1"
+  dependencies:
+    "@oxlint-tsgolint/darwin-arm64": "npm:0.22.1"
+    "@oxlint-tsgolint/darwin-x64": "npm:0.22.1"
+    "@oxlint-tsgolint/linux-arm64": "npm:0.22.1"
+    "@oxlint-tsgolint/linux-x64": "npm:0.22.1"
+    "@oxlint-tsgolint/win32-arm64": "npm:0.22.1"
+    "@oxlint-tsgolint/win32-x64": "npm:0.22.1"
+  dependenciesMeta:
+    "@oxlint-tsgolint/darwin-arm64":
+      optional: true
+    "@oxlint-tsgolint/darwin-x64":
+      optional: true
+    "@oxlint-tsgolint/linux-arm64":
+      optional: true
+    "@oxlint-tsgolint/linux-x64":
+      optional: true
+    "@oxlint-tsgolint/win32-arm64":
+      optional: true
+    "@oxlint-tsgolint/win32-x64":
+      optional: true
+  bin:
+    tsgolint: bin/tsgolint.js
+  checksum: 10c0/1f2e3840993e85ebe73f394e7e7441c1482aa4c7da38408c5887e2635be64a577edc887688c8a5232e9f3c8b963fbcecec93036e5fbf2fb863784175e1336aa4
+  languageName: node
+  linkType: hard
+
 "oxlint@npm:1.38.0":
   version: 1.38.0
   resolution: "oxlint@npm:1.38.0"