feat(turbopack): add support for polling file watcher

crates/napi/src/app_structure.rs

@@ -2,6 +2,7 @@ use std::{collections::HashMap, path::MAIN_SEPARATOR};
 
 use anyhow::{anyhow, Result};
 use indexmap::IndexMap;
+use next_api::project::WatchOptions;
 use next_core::app_structure::{
     find_app_dir, get_entrypoints as get_entrypoints_impl, Components, Entrypoint, Entrypoints,
     LoaderTree, MetadataItem, MetadataWithAltItem,
@@ -14,10 +15,15 @@ use turbo_tasks_fs::{DiskFileSystem, FileSystem, FileSystemPath};
 use turbopack_core::PROJECT_FILESYSTEM_NAME;
 
 #[turbo_tasks::function]
-async fn project_fs(project_dir: RcStr, watching: bool) -> Result<Vc<Box<dyn FileSystem>>> {
+async fn project_fs(
+    project_dir: RcStr,
+    watch_options: WatchOptions,
+) -> Result<Vc<Box<dyn FileSystem>>> {
     let disk_fs = DiskFileSystem::new(PROJECT_FILESYSTEM_NAME.into(), project_dir, vec![]);
-    if watching {
-        disk_fs.await?.start_watching_with_invalidation_reason()?;
+    if watch_options.enable {
+        disk_fs
+            .await?
+            .start_watching_with_invalidation_reason(watch_options.poll_interval)?;
     }
     Ok(Vc::upcast(disk_fs))
 }
@@ -329,10 +335,10 @@ async fn get_value(
     root_dir: RcStr,
     project_dir: RcStr,
     page_extensions: Vec<RcStr>,
-    watching: bool,
+    watch_options: WatchOptions,
 ) -> Result<Vc<OptionEntrypointsForJs>> {
     let page_extensions = Vc::cell(page_extensions);
-    let fs = project_fs(root_dir.clone(), watching);
+    let fs = project_fs(root_dir.clone(), watch_options);
     let project_relative = project_dir.strip_prefix(&*root_dir).unwrap();
     let project_relative = project_relative
         .strip_prefix(MAIN_SEPARATOR)

crates/napi/src/next_api/project.rs

@@ -10,7 +10,7 @@ use next_api::{
     entrypoints::Entrypoints,
     project::{
         DefineEnv, DraftModeOptions, Instrumentation, Middleware, PartialProjectOptions, Project,
-        ProjectContainer, ProjectOptions,
+        ProjectContainer, ProjectOptions, WatchOptions,
     },
     route::{Endpoint, Route},
 };
@@ -78,6 +78,16 @@ impl From<NapiDraftModeOptions> for DraftModeOptions {
     }
 }
 
+#[napi(object)]
+pub struct NapiWatchOptions {
+    /// Whether to watch the filesystem for file changes.
+    pub enable: bool,
+
+    /// Enable polling at a certain interval if the native file watching doesn't work (e.g.
+    /// docker).
+    pub poll_interval_ms: Option<f64>,
+}
+
 #[napi(object)]
 pub struct NapiProjectOptions {
     /// A root path from which all files must be nested under. Trying to access
@@ -91,8 +101,8 @@ pub struct NapiProjectOptions {
     /// deserializing next.config, so passing it as separate option.
     pub dist_dir: Option<String>,
 
-    /// Whether to watch he filesystem for file changes.
-    pub watch: bool,
+    /// Filesystem watcher options.
+    pub watch: NapiWatchOptions,
 
     /// The contents of next.config.js, serialized to JSON.
     pub next_config: String,
@@ -134,8 +144,8 @@ pub struct NapiPartialProjectOptions {
     /// deserializing next.config, so passing it as separate option.
     pub dist_dir: Option<Option<String>>,
 
-    /// Whether to watch he filesystem for file changes.
-    pub watch: Option<bool>,
+    /// Filesystem watcher options.
+    pub watch: Option<NapiWatchOptions>,
 
     /// The contents of next.config.js, serialized to JSON.
     pub next_config: Option<String>,
@@ -177,12 +187,23 @@ pub struct NapiTurboEngineOptions {
     pub memory_limit: Option<f64>,
 }
 
+impl From<NapiWatchOptions> for WatchOptions {
+    fn from(val: NapiWatchOptions) -> Self {
+        WatchOptions {
+            enable: val.enable,
+            poll_interval: val
+                .poll_interval_ms
+                .map(|interval| Duration::from_secs_f64(interval / 1000.0)),
+        }
+    }
+}
+
 impl From<NapiProjectOptions> for ProjectOptions {
     fn from(val: NapiProjectOptions) -> Self {
         ProjectOptions {
             root_path: val.root_path.into(),
             project_path: val.project_path.into(),
-            watch: val.watch,
+            watch: val.watch.into(),
             next_config: val.next_config.into(),
             js_config: val.js_config.into(),
             env: val
@@ -204,7 +225,7 @@ impl From<NapiPartialProjectOptions> for PartialProjectOptions {
         PartialProjectOptions {
             root_path: val.root_path.map(From::from),
             project_path: val.project_path.map(From::from),
-            watch: val.watch,
+            watch: val.watch.map(From::from),
             next_config: val.next_config.map(From::from),
             js_config: val.js_config.map(From::from),
             env: val.env.map(|env| {

crates/next-api/src/project.rs

@@ -1,4 +1,4 @@
-use std::path::MAIN_SEPARATOR;
+use std::{path::MAIN_SEPARATOR, time::Duration};
 
 use anyhow::{bail, Context, Result};
 use indexmap::{indexmap, map::Entry, IndexMap};
@@ -74,6 +74,19 @@ pub struct DraftModeOptions {
     pub preview_mode_signing_key: RcStr,
 }
 
+#[derive(
+    Debug, Default, Serialize, Deserialize, Copy, Clone, TaskInput, PartialEq, Eq, Hash, TraceRawVcs,
+)]
+#[serde(rename_all = "camelCase")]
+pub struct WatchOptions {
+    /// Whether to watch the filesystem for file changes.
+    pub enable: bool,
+
+    /// Enable polling at a certain interval if the native file watching doesn't work (e.g.
+    /// docker).
+    pub poll_interval: Option<Duration>,
+}
+
 #[derive(Debug, Serialize, Deserialize, Clone, TaskInput, PartialEq, Eq, Hash, TraceRawVcs)]
 #[serde(rename_all = "camelCase")]
 pub struct ProjectOptions {
@@ -97,8 +110,8 @@ pub struct ProjectOptions {
     /// time.
     pub define_env: DefineEnv,
 
-    /// Whether to watch the filesystem for file changes.
-    pub watch: bool,
+    /// Filesystem watcher options.
+    pub watch: WatchOptions,
 
     /// The mode in which Next.js is running.
     pub dev: bool,
@@ -136,8 +149,8 @@ pub struct PartialProjectOptions {
     /// time.
     pub define_env: Option<DefineEnv>,
 
-    /// Whether to watch the filesystem for file changes.
-    pub watch: Option<bool>,
+    /// Filesystem watcher options.
+    pub watch: Option<WatchOptions>,
 
     /// The mode in which Next.js is running.
     pub dev: Option<bool>,
@@ -402,8 +415,8 @@ pub struct Project {
     /// A path inside the root_path which contains the app/pages directories.
     pub project_path: RcStr,
 
-    /// Whether to watch the filesystem for file changes.
-    watch: bool,
+    /// Filesystem watcher options.
+    watch: WatchOptions,
 
     /// Next config.
     next_config: Vc<NextConfig>,
@@ -516,8 +529,10 @@ impl Project {
             this.root_path.clone(),
             vec![],
         );
-        if this.watch {
-            disk_fs.await?.start_watching_with_invalidation_reason()?;
+        if this.watch.enable {
+            disk_fs
+                .await?
+                .start_watching_with_invalidation_reason(this.watch.poll_interval)?;
         }
         Ok(disk_fs)
     }

crates/next-build-test/src/lib.rs

@@ -31,10 +31,10 @@ pub async fn main_inner(
 
     if matches!(strat, Strategy::Development { .. }) {
         options.dev = true;
-        options.watch = true;
+        options.watch.enable = true;
     } else {
         options.dev = false;
-        options.watch = false;
+        options.watch.enable = false;
     }
 
     let project = tt

crates/next-build-test/src/main.rs

@@ -153,7 +153,7 @@ fn main() {
                 },
                 project_path: canonical_path.to_string_lossy().into(),
                 root_path: "/".into(),
-                watch: false,
+                watch: Default::default(),
             };
 
             let json = serde_json::to_string_pretty(&options).unwrap();

packages/next/src/build/index.ts

@@ -1336,7 +1336,9 @@ export default async function build(
             rootPath: config.outputFileTracingRoot || dir,
             nextConfig: config,
             jsConfig: await getTurbopackJsConfig(dir, config),
-            watch: false,
+            watch: {
+              enable: false,
+            },
             dev,
             env: process.env as Record<string, string>,
             defineEnv: createDefineEnv({

packages/next/src/build/swc/generated-native.d.ts

@@ -80,6 +80,15 @@ export interface NapiDraftModeOptions {
   previewModeEncryptionKey: string
   previewModeSigningKey: string
 }
+export interface NapiWatchOptions {
+  /** Whether to watch the filesystem for file changes. */
+  enable: boolean
+  /**
+   * Enable polling at a certain interval if the native file watching doesn't work (e.g.
+   * docker).
+   */
+  pollIntervalMs?: number
+}
 export interface NapiProjectOptions {
   /**
    * A root path from which all files must be nested under. Trying to access
@@ -93,8 +102,8 @@ export interface NapiProjectOptions {
    * deserializing next.config, so passing it as separate option.
    */
   distDir?: string
-  /** Whether to watch he filesystem for file changes. */
-  watch: boolean
+  /** Filesystem watcher options. */
+  watch: NapiWatchOptions
   /** The contents of next.config.js, serialized to JSON. */
   nextConfig: string
   /** The contents of ts/config read by load-jsconfig, serialized to JSON. */
@@ -129,8 +138,8 @@ export interface NapiPartialProjectOptions {
    * deserializing next.config, so passing it as separate option.
    */
   distDir?: string | undefined | null
-  /** Whether to watch he filesystem for file changes. */
-  watch?: boolean
+  /** Filesystem watcher options. */
+  watch?: NapiWatchOptions
   /** The contents of next.config.js, serialized to JSON. */
   nextConfig?: string
   /** The contents of ts/config read by load-jsconfig, serialized to JSON. */

packages/next/src/build/swc/types.ts

@@ -346,7 +346,10 @@ export interface ProjectOptions {
   /**
    * Whether to watch the filesystem for file changes.
    */
-  watch: boolean
+  watch: {
+    enable: boolean
+    pollIntervalMs?: number
+  }
 
   /**
    * The mode in which Next.js is running.

packages/next/src/server/config-shared.ts

@@ -935,6 +935,10 @@ export interface NextConfig extends Record<string, any> {
    * were not detected on a per-page basis.
    */
   outputFileTracingIncludes?: Record<string, string[]>
+
+  watchOptions?: {
+    pollIntervalMs?: number
+  }
 }
 
 export const defaultConfig: NextConfig = {

packages/next/src/server/dev/hot-reloader-turbopack.ts

@@ -139,7 +139,10 @@ export async function createHotReloaderTurbopack(
       rootPath: opts.nextConfig.outputFileTracingRoot || dir,
       nextConfig: opts.nextConfig,
       jsConfig: await getTurbopackJsConfig(dir, nextConfig),
-      watch: true,
+      watch: {
+        enable: true,
+        pollIntervalMs: nextConfig.watchOptions?.pollIntervalMs,
+      },
       dev: true,
       env: process.env as Record<string, string>,
       defineEnv: createDefineEnv({

test/development/basic/next-rs-api.test.ts

@@ -200,7 +200,9 @@ describe('next.rs api', () => {
       rootPath: process.env.NEXT_SKIP_ISOLATE
         ? path.resolve(__dirname, '../../..')
         : next.testDir,
-      watch: true,
+      watch: {
+        enable: true,
+      },
       dev: true,
       defineEnv: createDefineEnv({
         isTurbopack: true,

turbopack/crates/node-file-trace/src/lib.rs

@@ -190,7 +190,7 @@ impl Args {
 async fn create_fs(name: &str, root: &str, watch: bool) -> Result<Vc<Box<dyn FileSystem>>> {
     let fs = DiskFileSystem::new(name.into(), root.into(), vec![]);
     if watch {
-        fs.await?.start_watching()?;
+        fs.await?.start_watching(None)?;
     } else {
         fs.await?.invalidate_with_reason();
     }

turbopack/crates/turbo-tasks-fs/examples/hash_directory.rs

@@ -31,7 +31,7 @@ async fn main() -> Result<()> {
         Box::pin(async {
             let root = current_dir().unwrap().to_str().unwrap().into();
             let disk_fs = DiskFileSystem::new("project".into(), root, vec![]);
-            disk_fs.await?.start_watching()?;
+            disk_fs.await?.start_watching(None)?;
 
             // Smart Pointer cast
             let fs: Vc<Box<dyn FileSystem>> = Vc::upcast(disk_fs);

turbopack/crates/turbo-tasks-fs/examples/hash_glob.rs

@@ -28,7 +28,7 @@ async fn main() -> Result<()> {
         Box::pin(async {
             let root = current_dir().unwrap().to_str().unwrap().into();
             let disk_fs = DiskFileSystem::new("project".into(), root, vec![]);
-            disk_fs.await?.start_watching()?;
+            disk_fs.await?.start_watching(None)?;
 
             // Smart Pointer cast
             let fs: Vc<Box<dyn FileSystem>> = Vc::upcast(disk_fs);

turbopack/crates/turbo-tasks-fs/src/embed/dir.rs

@@ -12,7 +12,7 @@ pub async fn directory_from_relative_path(
     path: RcStr,
 ) -> Result<Vc<Box<dyn FileSystem>>> {
     let disk_fs = DiskFileSystem::new(name, path, vec![]);
-    disk_fs.await?.start_watching()?;
+    disk_fs.await?.start_watching(None)?;
 
     Ok(Vc::upcast(disk_fs))
 }

turbopack/crates/turbo-tasks-fs/src/embed/file.rs

@@ -23,7 +23,7 @@ pub async fn content_from_relative_path(
         root_path.to_string_lossy().into(),
         vec![],
     );
-    disk_fs.await?.start_watching()?;
+    disk_fs.await?.start_watching(None)?;
 
     let fs_path = disk_fs.root().join(path.into());
     Ok(fs_path.read())