Deleting files should not crash Vite HMR

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Ensure `@tailwindcss/vite` doesn't crash in Deno v2.8.x when `context.parentURL` is not a valid URL ([#20245](https://github.com/tailwindlabs/tailwindcss/pull/20245))
 - Ensure `@tailwindcss/cli` in `--watch` mode rebuilds when the input CSS file changes in an ignored directory ([#20246](https://github.com/tailwindlabs/tailwindcss/pull/20246))
 - Ensure `@variant` rules generated by `addBase` can use custom variants defined later ([#20247](https://github.com/tailwindlabs/tailwindcss/pull/20247))
+- Ensure `@tailwindcss/vite` doesn't crash during HMR when scanned files or directories are deleted ([#20259](https://github.com/tailwindlabs/tailwindcss/pull/20259))
 
 ## [4.3.1] - 2026-06-12
 

crates/oxide/src/scanner/mod.rs

@@ -373,24 +373,28 @@ impl Scanner {
 
         let mut css_files: Vec<PathBuf> = vec![];
         let mut content_paths: Vec<(PathBuf, String)> = Vec::new();
-        let mut seen_files: FxHashSet<PathBuf> = FxHashSet::default();
+
+        // Fresh state
+        self.files.clear();
+        self.dirs.clear();
+        self.extensions.clear();
+        self.globs = None;
 
         for (path, is_dir, extension) in all_entries {
             if is_dir {
                 self.dirs.insert(path);
             } else {
                 // Deduplicate: parallel walk can visit the same file from multiple threads
-                if !seen_files.insert(path.clone()) {
+                if !self.files.insert(path.clone()) {
                     continue;
                 }
+                self.extensions.insert(extension.clone());
 
                 // On re-scans, check mtime to skip unchanged files.
                 // On the first scan we skip this entirely to avoid extra
                 // metadata syscalls.
                 let changed = if self.has_scanned_once {
-                    let current_mtime = std::fs::metadata(&path)
-                        .ok()
-                        .and_then(|m| m.modified().ok());
+                    let current_mtime = path.metadata().ok().and_then(|m| m.modified().ok());
 
                     match current_mtime {
                         Some(mtime) => {
@@ -403,26 +407,22 @@ impl Scanner {
                     true
                 };
 
+                if !changed {
+                    continue;
+                }
+
                 match extension.as_str() {
                     // Special handing for CSS files, we don't want to extract candidates from
                     // these files, but we do want to extract used CSS variables.
-                    "css" => {
-                        if changed {
-                            css_files.push(path.clone());
-                        }
-                    }
-                    _ => {
-                        if changed {
-                            content_paths.push((path.clone(), extension.clone()));
-                        }
-                    }
+                    "css" => css_files.push(path),
+                    _ => content_paths.push((path, extension)),
                 }
-
-                self.extensions.insert(extension);
-                self.files.insert(path);
             }
         }
 
+        // Ensure `mtimes` don't include stale files
+        self.mtimes.retain(|path, _| self.files.contains(path));
+
         // Read + preprocess all discovered files in parallel
         let scanned_blobs: Vec<Vec<u8>> = content_paths
             .into_par_iter()

crates/oxide/tests/scanner.rs

@@ -71,6 +71,41 @@ mod scanner {
         }
     }
 
+    fn scanned_files(scanner: &mut Scanner, base: &Path) -> Vec<String> {
+        let base_dir =
+            format!("{}{}", dunce::canonicalize(base).unwrap().display(), "/").replace('\\', "/");
+
+        let mut files = scanner
+            .get_files()
+            .iter()
+            // Normalize paths to use unix style separators
+            .map(|file| file.replace('\\', "/").replace(&base_dir, ""))
+            .collect::<Vec<_>>();
+        files.sort();
+        files
+    }
+
+    fn scanned_globs(scanner: &mut Scanner, base: &Path) -> Vec<String> {
+        let base_dir =
+            format!("{}{}", dunce::canonicalize(base).unwrap().display(), "/").replace('\\', "/");
+
+        let mut globs = scanner
+            .get_globs()
+            .iter()
+            .map(|glob| {
+                if glob.pattern.starts_with('/') {
+                    format!("{}{}", glob.base, glob.pattern)
+                } else {
+                    format!("{}/{}", glob.base, glob.pattern)
+                }
+            })
+            // Normalize paths to use unix style separators
+            .map(|file| file.replace('\\', "/").replace(&base_dir, ""))
+            .collect::<Vec<_>>();
+        globs.sort();
+        globs
+    }
+
     fn scan_with_globs(
         paths_with_content: &[(&str, &str)],
         source_directives: Vec<&str>,
@@ -95,34 +130,14 @@ mod scanner {
         let mut scanner = Scanner::new(sources);
 
         let candidates = scanner.scan();
-
         let base_dir =
             format!("{}{}", dunce::canonicalize(&base).unwrap().display(), "/").replace('\\', "/");
 
         // Get all scanned files as strings relative to the base directory
-        let mut files = scanner
-            .get_files()
-            .iter()
-            // Normalize paths to use unix style separators
-            .map(|file| file.replace('\\', "/").replace(&base_dir, ""))
-            .collect::<Vec<_>>();
-        files.sort();
+        let files = scanned_files(&mut scanner, Path::new(&base));
 
         // Get all scanned globs as strings relative to the base directory
-        let mut globs = scanner
-            .get_globs()
-            .iter()
-            .map(|glob| {
-                if glob.pattern.starts_with('/') {
-                    format!("{}{}", glob.base, glob.pattern)
-                } else {
-                    format!("{}/{}", glob.base, glob.pattern)
-                }
-            })
-            // Normalize paths to use unix style separators
-            .map(|file| file.replace('\\', "/").replace(&base_dir, ""))
-            .collect::<Vec<_>>();
-        globs.sort();
+        let globs = scanned_globs(&mut scanner, Path::new(&base));
 
         // Get all normalized sources as strings relative to the base directory
         let mut normalized_sources = scanner
@@ -910,6 +925,126 @@ mod scanner {
         );
     }
 
+    #[test]
+    fn it_should_remove_deleted_files_from_scanned_files() {
+        // Create a temporary working directory
+        let dir = tempdir().unwrap().into_path();
+
+        // Initialize this directory as a git repository
+        let _ = Command::new("git").arg("init").current_dir(&dir).output();
+
+        // Create files
+        create_files_in(
+            &dir,
+            &[
+                ("src/index.html", "content-['src/index.html']"),
+                ("src/keep.html", "content-['src/keep.html']"),
+                ("src/remove.html", "content-['src/remove.html']"),
+            ],
+        );
+
+        let mut scanner = Scanner::new(vec![public_source_entry_from_pattern(
+            dir.clone(),
+            "@source '**/*'",
+        )]);
+
+        scanner.scan();
+        assert_eq!(
+            scanned_files(&mut scanner, &dir),
+            vec!["src/index.html", "src/keep.html", "src/remove.html"]
+        );
+
+        fs::remove_file(dir.join("src/remove.html")).unwrap();
+
+        scanner.scan();
+        assert_eq!(
+            scanned_files(&mut scanner, &dir),
+            vec!["src/index.html", "src/keep.html"]
+        );
+    }
+
+    #[test]
+    fn it_should_remove_deleted_directories_from_scanned_files() {
+        // Create a temporary working directory
+        let dir = tempdir().unwrap().into_path();
+
+        // Initialize this directory as a git repository
+        let _ = Command::new("git").arg("init").current_dir(&dir).output();
+
+        // Create files
+        create_files_in(
+            &dir,
+            &[
+                ("src/index.html", "content-['src/index.html']"),
+                ("src/keep/index.html", "content-['src/keep/index.html']"),
+                ("src/remove/index.html", "content-['src/remove/index.html']"),
+                (
+                    "src/remove/nested/index.html",
+                    "content-['src/remove/nested/index.html']",
+                ),
+            ],
+        );
+
+        let mut scanner = Scanner::new(vec![public_source_entry_from_pattern(
+            dir.clone(),
+            "@source '**/*'",
+        )]);
+
+        scanner.scan();
+        assert_eq!(
+            scanned_files(&mut scanner, &dir),
+            vec![
+                "src/index.html",
+                "src/keep/index.html",
+                "src/remove/index.html",
+                "src/remove/nested/index.html",
+            ]
+        );
+
+        fs::remove_dir_all(dir.join("src/remove")).unwrap();
+
+        scanner.scan();
+        assert_eq!(
+            scanned_files(&mut scanner, &dir),
+            vec!["src/index.html", "src/keep/index.html"]
+        );
+    }
+
+    #[test]
+    fn it_should_remove_deleted_directories_from_scanned_globs() {
+        // Create a temporary working directory
+        let dir = tempdir().unwrap().into_path();
+
+        // Initialize this directory as a git repository
+        let _ = Command::new("git").arg("init").current_dir(&dir).output();
+
+        // Create files
+        create_files_in(
+            &dir,
+            &[
+                ("index.html", "content-['index.html']"),
+                ("src/index.html", "content-['src/index.html']"),
+            ],
+        );
+
+        let mut scanner = Scanner::new(vec![public_source_entry_from_pattern(
+            dir.clone(),
+            "@source '**/*'",
+        )]);
+
+        scanner.scan();
+
+        let globs = scanned_globs(&mut scanner, &dir);
+        assert!(globs.iter().any(|glob| glob.starts_with("src/**/*")));
+
+        fs::remove_dir_all(dir.join("src")).unwrap();
+
+        scanner.scan();
+
+        let globs = scanned_globs(&mut scanner, &dir);
+        assert!(!globs.iter().any(|glob| glob.starts_with("src/**/*")));
+    }
+
     #[test]
     fn it_should_ignore_negated_custom_sources() {
         let ScanResult {

integrations/vite/index.test.ts

@@ -1275,3 +1275,100 @@ test(
     await fs.expectFileToContain(filename, [candidate`content-['index.html']`])
   },
 )
+
+// https://github.com/tailwindlabs/tailwindcss/issues/17532
+test(
+  'deleting a file should not crash Vite',
+  {
+    fs: {
+      'package.json': json`
+        {
+          "type": "module",
+          "dependencies": {
+            "@tailwindcss/vite": "workspace:^",
+            "tailwindcss": "workspace:^"
+          },
+          "devDependencies": {
+            "vite": "6.2.5"
+          }
+        }
+      `,
+      'vite.config.ts': ts`
+        import tailwindcss from '@tailwindcss/vite'
+        import { defineConfig } from 'vite'
+
+        export default defineConfig({
+          plugins: [tailwindcss()],
+        })
+      `,
+      'index.html': html`
+        <body>
+          <div id="app" class="underline"></div>
+          <script type="module" src="./src/main.js"></script>
+        </body>
+      `,
+      'src/index.css': css`@import 'tailwindcss';`,
+      'src/main.js': js`
+        import iconUrl from './assets/icon.svg?url'
+        import './index.css'
+
+        document.querySelector('#app').innerHTML = iconUrl
+      `,
+      'src/assets/icon.svg': html`
+        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 1">
+          <rect class="fill-red-500" width="1" height="1" />
+        </svg>
+       `,
+    },
+  },
+  async ({ fs, spawn, expect }) => {
+    let process = await spawn('pnpm vite dev')
+    await process.onStdout((m) => m.includes('ready in'))
+
+    let url = ''
+    await process.onStdout((m) => {
+      let match = /Local:\s*(http.*)\//.exec(m)
+      if (match) url = match[1]
+      return Boolean(url)
+    })
+
+    await retryAssertion(async () => {
+      let [main, css] = await Promise.all([
+        fetch(`${url}/src/main.js`).then((r) => r.text()),
+        fetch(`${url}/src/index.css`).then((r) => r.text()),
+      ])
+
+      expect(main).toContain('/src/assets/icon.svg?import&url')
+      expect(main).toContain('/src/index.css')
+      expect(css).toContain('.fill-red-500')
+    })
+
+    process.flush()
+
+    let unexpectedError = process.onStderr((m) => {
+      return /error|crash|panic/i.test(m)
+    })
+
+    await fs.write(
+      'src/main.js',
+      js`
+        import './index.css'
+        document.querySelector('#app').innerHTML = 'Hello World'
+      `,
+    )
+
+    await fs.delete('src/assets/icon.svg')
+
+    let result = await Promise.race([
+      unexpectedError.then(() => 'stderr'),
+      new Promise((resolve) => setTimeout(() => resolve('timeout'), 500)),
+    ])
+
+    expect(result).toBe('timeout')
+
+    await retryAssertion(async () => {
+      let response = await fetch(`${url}/src/index.css?t=${Date.now()}`)
+      expect(response.status).toBe(200)
+    })
+  },
+)