feat: usercss compilation and better settings storage

package.json

@@ -42,10 +42,12 @@
     },
     "devDependencies": {
         "@types/diff": "^5.0.3",
+        "@types/less": "^3.0.4",
         "@types/lodash": "^4.14.194",
         "@types/node": "^18.16.3",
         "@types/react": "^18.2.0",
         "@types/react-dom": "^18.2.1",
+        "@types/stylus": "^0.48.39",
         "@types/yazl": "^2.4.2",
         "@typescript-eslint/eslint-plugin": "^5.59.1",
         "@typescript-eslint/parser": "^5.59.1",
@@ -71,7 +73,8 @@
     "pnpm": {
         "patchedDependencies": {
             "eslint-plugin-path-alias@1.0.0": "patches/eslint-plugin-path-alias@1.0.0.patch",
-            "eslint@8.46.0": "patches/eslint@8.46.0.patch"
+            "eslint@8.46.0": "patches/eslint@8.46.0.patch",
+            "@types/less@3.0.4": "patches/@types__less@3.0.4.patch"
         },
         "peerDependencyRules": {
             "ignoreMissing": [

patches/@types__less@3.0.4.patch

@@ -0,0 +1,13 @@
+diff --git a/index.d.ts b/index.d.ts
+index eb4f07d47b932fb9cc8c8cd451ab107f648bd013..18a3e15a1997734e1773718e5be55d252ed9478c 100644
+--- a/index.d.ts
++++ b/index.d.ts
+@@ -306,7 +306,5 @@ interface LessStatic {
+ }
+ 
+ declare module "less" {
+-    export = less;
++    export = LessStatic;
+ }
+-
+-declare var less: LessStatic;

pnpm-lock.yaml

@@ -1,6 +1,9 @@
 lockfileVersion: '6.0'
 
 patchedDependencies:
+  '@types/less@3.0.4':
+    hash: krcufrsfhsuxuoj7hocqugs6zi
+    path: patches/@types__less@3.0.4.patch
   eslint-plugin-path-alias@1.0.0:
     hash: m6sma4g6bh67km3q6igf6uxaja
     path: patches/eslint-plugin-path-alias@1.0.0.patch
@@ -38,6 +41,9 @@ devDependencies:
   '@types/diff':
     specifier: ^5.0.3
     version: 5.0.3
+  '@types/less':
+    specifier: ^3.0.4
+    version: 3.0.4(patch_hash=krcufrsfhsuxuoj7hocqugs6zi)
   '@types/lodash':
     specifier: ^4.14.194
     version: 4.14.194
@@ -50,6 +56,9 @@ devDependencies:
   '@types/react-dom':
     specifier: ^18.2.1
     version: 18.2.1
+  '@types/stylus':
+    specifier: ^0.48.39
+    version: 0.48.39
   '@types/yazl':
     specifier: ^2.4.2
     version: 2.4.2
@@ -531,6 +540,11 @@ packages:
     resolution: {integrity: sha512-wOuvG1SN4Us4rez+tylwwwCV1psiNVOkJeM3AUWUNWg/jDQY2+HE/444y5gc+jBmRqASOm2Oeh5c1axHobwRKQ==}
     dev: true
 
+  /@types/less@3.0.4(patch_hash=krcufrsfhsuxuoj7hocqugs6zi):
+    resolution: {integrity: sha512-djlMpTdDF+tLaqVpK/0DWGNIr7BFjN8ykDLkgS0sQGYYLop51imRRE3foTjl+dMAH1zFE8bMZAG0VbYPEcSgsA==}
+    dev: true
+    patched: true
+
   /@types/lodash@4.14.194:
     resolution: {integrity: sha512-r22s9tAS7imvBt2lyHC9B8AGwWnXaYb1tY09oyLkXDs4vArpYJzw09nj8MLx5VfciBPGIb+ZwG0ssYnEPJxn/g==}
     dev: true
@@ -580,6 +594,12 @@ packages:
     resolution: {integrity: sha512-21cFJr9z3g5dW8B0CVI9g2O9beqaThGQ6ZFBqHfwhzLDKUxaqTIy3vnfah/UPkfOiF2pLq+tGz+W8RyCskuslw==}
     dev: true
 
+  /@types/stylus@0.48.39:
+    resolution: {integrity: sha512-98a0QrJorrq8+Vsan9yfxol2Qr6nvUWBeV3oYnSMks4QdLMebAzZvRd9IuoZOcnB6Erfjcjn1J2J+63MPCxJnw==}
+    dependencies:
+      '@types/node': 18.16.3
+    dev: true
+
   /@types/yauzl@2.10.0:
     resolution: {integrity: sha512-Cn6WYCm0tXv8p6k+A8PvbDG763EDpBoTzHdA+Q/MF6H3sapGjCm9NzoaJncJS9tUKSuCoDs9XHxYYsQDgxR6kw==}
     requiresBuild: true

src/api/Settings.ts

@@ -62,7 +62,11 @@ export interface Settings {
         settingsSyncVersion: number;
     };
 
-    userCssVars: Record<string, string>;
+    userCssVars: {
+        [fileName: string]: {
+            [varName: string]: string;
+        };
+    };
 }
 
 const DefaultSettings: Settings = {

src/utils/dependencies.ts

@@ -16,6 +16,9 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
+import type StylusRenderer = require("stylus/lib/renderer");
+import type LessStatic from "less";
+
 import { makeLazy } from "./lazy";
 
 /*
@@ -85,3 +88,18 @@ export const rnnoiseWorkletSrc = `${rnnoiseDist}/rnnoise/workletProcessor.js`;
 
 // @ts-expect-error SHUT UP
 export const getStegCloak = makeLazy(() => import("https://unpkg.com/stegcloak-dist@1.0.0/index.js"));
+
+export const getStylus = makeLazy(async () => {
+    const stylusScript = await fetch("https://unpkg.com/stylus-lang-bundle@0.58.1/dist/stylus-renderer.min.js").then(r => r.text());
+    // the stylus bundle doesn't have a header that checks for export conditions so we can just patch the script to
+    // return the renderer itself
+    const patchedScript = stylusScript.replace("var StylusRenderer=", "return ");
+    return Function(patchedScript)() as typeof StylusRenderer;
+});
+
+export const getLess = makeLazy(async () => {
+    const lessScript = await fetch("https://unpkg.com/less@4.2.0/dist/less.min.js").then(r => r.text());
+    const module = { exports: {} };
+    Function("module", "exports", lessScript)(module, module.exports);
+    return module.exports as LessStatic;
+});

src/utils/quickCss.ts

@@ -17,7 +17,9 @@
 */
 
 import { addSettingsListener, Settings } from "@api/Settings";
-import { parse as usercssParse } from "@utils/themes/usercss";
+
+import { compileUsercss } from "./themes/usercss/compiler";
+
 
 let style: HTMLStyleElement;
 let themesStyle: HTMLStyleElement;
@@ -51,39 +53,30 @@ async function initThemes() {
     const links: string[] = [...themeLinks];
 
     if (IS_WEB) {
-        for (const theme of enabledThemes) {
+        // UserCSS handled separately
+        for (const theme of enabledThemes) if (!theme.endsWith(".user.css")) {
             const themeData = await VencordNative.themes.getThemeData(theme);
             if (!themeData) continue;
+
             const blob = new Blob([themeData], { type: "text/css" });
             links.push(URL.createObjectURL(blob));
         }
     } else {
-        const localThemes = enabledThemes.map(theme => `vencord:///themes/${theme}?v=${Date.now()}`);
-        links.push(...localThemes);
+        for (const theme of enabledThemes) if (!theme.endsWith(".user.css")) {
+            links.push(`vencord:///themes/${theme}?v=${Date.now()}`);
+        }
     }
 
-    const cssVars: string[] = [];
-
-    // for UserCSS, we need to inject the variables
     for (const theme of enabledThemes) if (theme.endsWith(".user.css")) {
-        const themeData = await VencordNative.themes.getThemeData(theme);
-        if (!themeData) continue;
+        // UserCSS goes through a compile step first
+        const css = await compileUsercss(theme);
+        if (!css) continue; // something went wrong during the compile step...
 
-        const { vars } = usercssParse(themeData, theme);
-
-        for (const [id, meta] of Object.entries(vars)) {
-            let normalizedValue: string = userCssVars[id] ?? meta.default;
-
-            if (meta.type === "range") {
-                normalizedValue = `${normalizedValue}${meta.units ?? ""}`;
-            }
-
-            cssVars.push(`--${id}:${normalizedValue};`);
-        }
+        const blob = new Blob([css], { type: "text/css" });
+        links.push(URL.createObjectURL(blob));
     }
 
     themesStyle.textContent = links.map(link => `@import url("${link.trim()}");`).join("\n");
-    if (cssVars.length > 0) themesStyle.textContent += `:root{${cssVars.join("\n")}}`;
 }
 
 document.addEventListener("DOMContentLoaded", () => {

src/utils/themes/usercss/compiler.ts

@@ -0,0 +1,88 @@
+/*
+ * Vencord, a Discord client mod
+ * Copyright (c) 2023 Vendicated and contributors
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+import { Settings } from "@api/Settings";
+import { getLess, getStylus } from "@utils/dependencies";
+import { Logger } from "@utils/Logger";
+
+import { parse as usercssParse } from ".";
+
+const UserCSSLogger = new Logger("UserCSS:Compiler", "#d2acf5");
+
+const preprocessors: { [preprocessor: string]: (text: string, vars: Record<string, string>) => Promise<string>; } = {
+    async default(text: string, vars: Record<string, string>) {
+        const variables = Object.entries(vars)
+            .map(([name, value]) => `--${name}: ${value}`)
+            .join("; ");
+
+        return `/* ==Vencord== */\n:root{${variables}}\n/* ==/Vencord== */${text}`;
+    },
+
+    async uso(text: string, vars: Record<string, string>) {
+        for (const [k, v] of Object.entries(vars)) {
+            text = text.replace(new RegExp(`\\/\\*\\[\\[${k}\\]\\]\\*\\/`, "g"), v);
+        }
+
+        return text;
+    },
+
+    async stylus(text: string, vars: Record<string, string>) {
+        const StylusRenderer = await getStylus();
+
+        const variables = Object.entries(vars)
+            .map(([name, value]) => `${name} = ${value}`)
+            .join("\n");
+
+        const stylusDoc = `// ==Vencord==\n${variables}\n// ==/Vencord==\n${text}`;
+
+        return new StylusRenderer(stylusDoc).render();
+    },
+
+    async less(text: string, vars: Record<string, string>) {
+        const less = await getLess();
+
+        const variables = Object.entries(vars)
+            .map(([name, value]) => `@${name}: ${value};`)
+            .join("\n");
+
+        const lessDoc = `// ==Vencord==\n${variables}\n// ==/Vencord==\n${text}`;
+
+        return less.render(lessDoc).then(r => r.css);
+    }
+};
+
+export async function compileUsercss(fileName: string) {
+    const themeData = await VencordNative.themes.getThemeData(fileName);
+    if (!themeData) return null;
+
+    const { preprocessor: definedPreprocessor, vars } = usercssParse(themeData, fileName);
+
+    // UserCSS preprocessor order look like this:
+    // - use the preprocessor defined
+    // - if variables are set, `uso`
+    // - otherwise, `default`
+    const usedPreprocessor = definedPreprocessor ?? (Object.keys(vars).length > 0 ? "uso" : "default");
+
+    const preprocessorFn = preprocessors[usedPreprocessor];
+
+    if (!preprocessorFn) {
+        UserCSSLogger.error("File", fileName, "requires preprocessor", usedPreprocessor, "which isn't known to Vencord");
+        return null;
+    }
+
+    const varsToPass = {};
+
+    for (const [k, v] of Object.entries(vars)) {
+        varsToPass[k] = Settings.userCssVars[fileName]?.[k] ?? v.default;
+    }
+
+    try {
+        return await preprocessorFn(themeData, varsToPass);
+    } catch (error) {
+        UserCSSLogger.error("File", fileName, "failed to compile with preprocessor", usedPreprocessor, error);
+        return null;
+    }
+}

src/utils/themes/usercss/index.ts

@@ -4,10 +4,18 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
+import { Logger } from "@utils/Logger";
 import { parse as originalParse, UserstyleHeader } from "usercss-meta";
 
+const UserCSSLogger = new Logger("UserCSS", "#d2acf5");
+
 export function parse(text: string, fileName: string): UserstyleHeader {
-    const { metadata } = originalParse(text.replace(/\r/g, ""));
+    const { metadata, errors } = originalParse(text.replace(/\r/g, ""));
+
+    if (errors.length) {
+        UserCSSLogger.warn("Parsed", fileName, "with errors:", errors);
+    }
+
     return {
         ...metadata,
         fileName,

src/utils/themes/usercss/usercss-meta.d.ts

@@ -93,10 +93,8 @@ declare module "usercss-meta" {
         license?: string;
         /**
          * The CSS preprocessor used to write this style.
-         *
-         * @vencord Unimplemented in Vencord, just part of the metadata.
          */
-        preprocessor?: string;
+        preprocessor?: "default" | "uso" | "less" | "stylus";
 
         /**
          * A list of variables the style defines.
@@ -104,5 +102,5 @@ declare module "usercss-meta" {
         vars: Record<string, UserCSSVariable>;
     }
 
-    export function parse(text: string): { metadata: UserstyleHeader; };
+    export function parse(text: string): { metadata: UserstyleHeader; errors: { code: string; args: any; }[] };
 }