🐛 Enable usePolling on Windows to fix file-lock

docs/user/config.adoc

@@ -42,7 +42,8 @@ There's no support for multiple config files or inheriting/overriding config fil
 		"language": "Default",
 		"permissionLevel": 2,
 		"plugins": [],
-		"mcmetaSummaryOverrides": {}
+		"mcmetaSummaryOverrides": {},
+		useFilePolling: false
 	},
 	"format": {
 		"blockStateBracketSpacing": { "inside": 0 },

packages/core/src/common/externals/NodeJsExternals.ts

@@ -117,8 +117,10 @@ export const NodeJsExternals: Externals = {
 		unlink(location) {
 			return fsp.unlink(toFsPathLike(location))
 		},
-		watch(locations) {
-			return new ChokidarWatcherWrapper(chokidar.watch(locations.map(toPath)))
+		watch(locations, { usePolling = false } = {}) {
+			return new ChokidarWatcherWrapper(
+				chokidar.watch(locations.map(toPath), { usePolling }),
+			)
 		},
 		writeFile(location, data, options) {
 			return fsp.writeFile(toFsPathLike(location), data, options)

packages/core/src/common/externals/index.ts

@@ -71,7 +71,7 @@ export interface ExternalFileSystem {
 	showFile(path: FsLocation): Promise<void>
 	stat(location: FsLocation): Promise<{ isDirectory(): boolean; isFile(): boolean }>
 	unlink(location: FsLocation): Promise<void>
-	watch(locations: FsLocation[]): FsWatcher
+	watch(locations: FsLocation[], options: { usePolling?: boolean }): FsWatcher
 	/**
 	 * @param options `mode` - File mode bit mask (e.g. `0o775`).
 	 */

packages/core/src/service/Config.ts

@@ -115,6 +115,16 @@ export interface EnvConfig {
 	>
 	permissionLevel: 1 | 2 | 3 | 4
 	plugins: string[]
+	/**
+	 * Makes the file-watcher use polling to watch for file changes.
+	 * Comes at a performance cost for very large datapacks.
+	 *
+	 * On Windows, enabling this can fix file-lock issues when Spyglass is running.
+	 * See: https://github.com/SpyglassMC/Spyglass/issues/1414
+	 *
+	 * **You should only consider enabling this for Windows machines.**
+	 */
+	useFilePolling: boolean
 }
 
 export type LinterSeverity = 'hint' | 'information' | 'warning' | 'error'
@@ -352,6 +362,7 @@ export const VanillaConfig: Config = {
 		permissionLevel: 2,
 		plugins: [],
 		mcmetaSummaryOverrides: {},
+		useFilePolling: false,
 	},
 	format: {
 		blockStateBracketSpacing: { inside: 0 },

packages/core/src/service/Project.ts

@@ -511,7 +511,9 @@ export class Project implements ExternalEventEmitter {
 				}
 				this.#watchedFiles.clear()
 				this.#watcherReady = false
-				this.#watcher = this.externals.fs.watch(this.projectRoots).once('ready', () => {
+				this.#watcher = this.externals.fs.watch(this.projectRoots, {
+					usePolling: this.config.env.useFilePolling,
+				}).once('ready', () => {
 					this.#watcherReady = true
 					resolve()
 				}).on('add', (uri) => {