Fix fantasticon usage on Windows, add Windows PR check

.fantasticonrc.js

@@ -3,11 +3,15 @@ var pkg = require('./package.json');
 var path = require('path');
 var mapping = require('./src/template/mapping.json');
 
-// Ensure paths are platform-agnostic for Windows CI
-var inputDir = path.resolve(__dirname, 'src', 'icons');
-var outputDir = path.resolve(__dirname, 'dist');
-var templateHtml = path.resolve(__dirname, 'src', 'template', 'preview.hbs');
-var templateCss = path.resolve(__dirname, 'src', 'template', 'styles.hbs');
+function normalizePath(filePath) {
+    return filePath.replace(/\\/g, '/');
+}
+
+// Fantasticon 4.x uses glob patterns internally, which require forward slashes.
+var inputDir = normalizePath(path.resolve(__dirname, 'src', 'icons'));
+var outputDir = normalizePath(path.resolve(__dirname, 'dist'));
+var templateHtml = normalizePath(path.resolve(__dirname, 'src', 'template', 'preview.hbs'));
+var templateCss = normalizePath(path.resolve(__dirname, 'src', 'template', 'styles.hbs'));
 
 // Convert new mapping format back to alias -> code format for fantasticon
 // New format: { "code": ["alias1", "alias2", ...] }

.github/workflows/release.yml

@@ -63,3 +63,21 @@ jobs:
           asset_path: ./dist/codicon.ttf
           asset_name: codicon-font-${{ github.ref_name }}.ttf
           asset_content_type: application/x-font-ttf
+
+  windows-pr-build:
+    if: github.event_name == 'pull_request'
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build font
+        run: npm run build

package.json

@@ -16,7 +16,7 @@
     "embed-metadata": "node ./scripts/embed-metadata.js",
     "embed-svg-data": "node ./scripts/embed-svg-data.js",
     "check-metadata": "node ./scripts/check-metadata.js",
-    "fonts": "fantasticon",
+    "fonts": "node ./scripts/patch-fantasticon.js && fantasticon",
     "dev": "npm run build && npm run replace-in-vscode",
     "build": "npm run clean && npm run svgo && npm run fonts && npm run export-to-ts && npm run export-to-csv && npm run copy-metadata && npm run embed-metadata && npm run embed-svg-data && npm run sprite",
     "version:bump": "node ./scripts/version-bump.js",

scripts/patch-fantasticon.js

@@ -0,0 +1,95 @@
+/*
+ * Temporary Windows compatibility patch for Fantasticon.
+ *
+ * Context:
+ * https://github.com/tancredi/fantasticon/issues/470
+ *
+ * Fantasticon 4.x builds the SVG discovery pattern internally using `path.join`
+ * and then passes that pattern into `glob`. On Windows, `path.join` emits
+ * backslashes, so the generated pattern looks like:
+ *
+ *   D:\a\vscode-codicons\vscode-codicons\src\icons\**\*.svg
+ *
+ * The `glob` package does not interpret those backslashes as path separators in
+ * a glob expression. Instead, they are treated as escape characters. The result
+ * is that the pattern matches zero files, even though the icons are present on
+ * disk and earlier build steps such as `svgo -f ./src/icons/` can see them.
+ *
+ * That is why the CI failure looks misleading:
+ *
+ *   No SVGs found in D:/a/vscode-codicons/vscode-codicons/src/icons
+ *
+ * The directory exists. The files exist. The problem is the glob pattern that
+ * Fantasticon constructs internally before it searches for the files.
+ *
+ * We already normalize the paths we pass into `.fantasticonrc.js`, but that is
+ * not sufficient because Fantasticon recreates the broken Windows pattern inside
+ * its own compiled runtime. The upstream issue thread repeatedly points to the
+ * same low-level fix: normalize the generated glob path to forward slashes
+ * before `glob` receives it.
+ *
+ * This script applies exactly that workaround to the installed Fantasticon
+ * package on Windows before the `fantasticon` CLI is executed. It patches both
+ * the library bundle and the CLI bundle because the published package contains
+ * duplicated compiled entrypoints under `dist/`.
+ *
+ * Scope and intent:
+ * - Windows only
+ * - No-op on macOS/Linux
+ * - Idempotent if the dependency is already patched
+ * - Fails loudly if Fantasticon changes shape and the expected line is no longer
+ *   present, because a silent no-op would hide a broken release path
+ *
+ * This should be considered a repository-side compatibility shim until the
+ * upstream fix from the Fantasticon issue/PR thread lands in a released version
+ * that we can consume directly.
+ */
+const fs = require('fs');
+const path = require('path');
+
+if (process.platform !== 'win32') {
+    process.exit(0);
+}
+
+const targetFiles = [
+    path.resolve(__dirname, '..', 'node_modules', 'fantasticon', 'dist', 'index.cjs'),
+    path.resolve(__dirname, '..', 'node_modules', 'fantasticon', 'dist', 'cli', 'index.cjs')
+];
+
+const replacementSuffix = ".replace(/\\\\/g, '/')";
+const targetSnippet = '`**/*.${ASSETS_EXTENSION}`';
+let patchedFileCount = 0;
+let alreadyPatchedCount = 0;
+
+for (const targetFile of targetFiles) {
+    if (!fs.existsSync(targetFile)) {
+        continue;
+    }
+
+    const originalContent = fs.readFileSync(targetFile, 'utf8');
+    const patchedContent = originalContent
+        .split('\n')
+        .map((line) => {
+            if (!line.includes('const globPath = ') || !line.includes(targetSnippet) || line.includes(replacementSuffix)) {
+                return line;
+            }
+
+            return line.replace(';', `${replacementSuffix};`);
+        })
+        .join('\n');
+
+    if (patchedContent !== originalContent) {
+        fs.writeFileSync(targetFile, patchedContent, 'utf8');
+        patchedFileCount += 1;
+        continue;
+    }
+
+    if (originalContent.includes(replacementSuffix)) {
+        alreadyPatchedCount += 1;
+    }
+}
+
+if (patchedFileCount === 0 && alreadyPatchedCount === 0) {
+    console.error('fantasticon-fix: expected globPath pattern not found in installed Fantasticon files.');
+    process.exit(1);
+}