From a07ffbc4be6ba31deb21da5ad328fa43f34cc8d9 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 22 Aug 2025 16:37:42 +0000
Subject: [PATCH 1/3] Initial plan


From 7fc1c217c0962d3ae8922983ecbff6515890a2bb Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 22 Aug 2025 16:43:25 +0000
Subject: [PATCH 2/3] feat: add FileSystem observer API types

Co-authored-by: streamich <9773803+streamich@users.noreply.github.com>
---
 src/fsa/types.ts | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/src/fsa/types.ts b/src/fsa/types.ts
index e87dfd21c..4023ca1a0 100644
--- a/src/fsa/types.ts
+++ b/src/fsa/types.ts
@@ -126,3 +126,32 @@ export type Data =
   | DataView
   | Blob
   | string;
+
+/**
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/FileSystemChangeRecord
+ */
+export interface FileSystemChangeRecord {
+  /** The changed file system handle. */
+  changedHandle: IFileSystemHandle;
+  /** Path components from the observed directory to the changed handle. */
+  relativePathComponents: string[];
+  /** The type of change that occurred. */
+  type: 'appeared' | 'disappeared' | 'modified';
+}
+
+export interface FileSystemObserverObserveOptions {
+  /** Whether to observe changes recursively in subdirectories. */
+  recursive?: boolean;
+}
+
+/**
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/FileSystemObserver
+ */
+export interface FileSystemObserver {
+  /** Start observing changes to a directory handle. */
+  observe(handle: IFileSystemDirectoryHandle, options?: FileSystemObserverObserveOptions): Promise<void>;
+  /** Stop observing changes to a directory handle. */
+  unobserve(handle: IFileSystemDirectoryHandle): void;
+  /** Disconnect and stop all observations. */
+  disconnect(): void;
+}

From 38e2f13856eaedfbca83eae7770f07a755e74c91 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 22 Aug 2025 21:05:50 +0000
Subject: [PATCH 3/3] feat: update FileSystem observer API types with complete
 spec compliance

Co-authored-by: streamich <9773803+streamich@users.noreply.github.com>
---
 src/fsa/types.ts | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/fsa/types.ts b/src/fsa/types.ts
index 4023ca1a0..8af90fc6d 100644
--- a/src/fsa/types.ts
+++ b/src/fsa/types.ts
@@ -131,12 +131,26 @@ export type Data =
  * @see https://developer.mozilla.org/en-US/docs/Web/API/FileSystemChangeRecord
  */
 export interface FileSystemChangeRecord {
-  /** The changed file system handle. */
-  changedHandle: IFileSystemHandle;
+  /**
+   * The changed file system handle.
+   * This property will be null for records with a "disappeared", "errored", or "unknown" type.
+   */
+  changedHandle: IFileSystemHandle | IFileSystemSyncAccessHandle | null;
   /** Path components from the observed directory to the changed handle. */
   relativePathComponents: string[];
+  /**
+   * Path components that make up the relative file path from the root to the
+   * changedHandle's former location, in the case of observations with a "moved" type.
+   * If the type is not "moved", this property will be null.
+   */
+  relativePathMovedFrom: string[] | null;
+  /**
+   * A reference to the root file system handle, that is, the one passed to the observe()
+   * call that started the observation.
+   */
+  root: IFileSystemHandle | IFileSystemSyncAccessHandle;
   /** The type of change that occurred. */
-  type: 'appeared' | 'disappeared' | 'modified';
+  type: 'appeared' | 'disappeared' | 'modified' | 'moved' | 'errored' | 'unknown';
 }
 
 export interface FileSystemObserverObserveOptions {
@@ -147,7 +161,13 @@ export interface FileSystemObserverObserveOptions {
 /**
  * @see https://developer.mozilla.org/en-US/docs/Web/API/FileSystemObserver
  */
-export interface FileSystemObserver {
+export interface IFileSystemObserver {
+  /**
+   * Constructor for creating a FileSystemObserver.
+   * @param callback - Function called with file system change records and the observer instance
+   */
+  new (callback: (records: FileSystemChangeRecord[], observer: IFileSystemObserver) => void): IFileSystemObserver;
+
   /** Start observing changes to a directory handle. */
   observe(handle: IFileSystemDirectoryHandle, options?: FileSystemObserverObserveOptions): Promise<void>;
   /** Stop observing changes to a directory handle. */