From dd5393889d8d69cdcfa5c13f596e5b270964b8e4 Mon Sep 17 00:00:00 2001
From: Austin Sullivan <asully@chromium.org>
Date: Fri, 11 Nov 2022 23:32:09 +0000
Subject: [PATCH 1/2] remove duplication with whatwg/fs

Fixes #342, fixes #370
---
 index.bs | 970 ++-----------------------------------------------------
 1 file changed, 21 insertions(+), 949 deletions(-)

diff --git a/index.bs b/index.bs
index 99d0bbe..6e5b507 100644
--- a/index.bs
+++ b/index.bs
@@ -1,7 +1,7 @@
 <pre class=metadata>
 Title: File System Access
 Shortname: file-system-access
-Abstract: This document defines a web platform API that enables developers to build
+Abstract: This document extends the API in [[FS]] to enables developers to build
   powerful web apps that interact with files on the user's local device.
   It builds on [[FILE-API|File API]] for file reading capabilities, and adds new API
   surface to enable modifying files, as well as working with directories.
@@ -25,6 +25,12 @@ urlPrefix: https://tc39.github.io/ecma262/; spec: ECMA-262
   type: dfn; text: realm; url: realm
 urlPrefix: https://storage.spec.whatwg.org/; spec: storage
   type: dfn; text: storage; url: site-storage
+urlPrefix: https://fs.spec.whatwg.org/; spec: fs
+  type: dfn; text: binary data; url: file-entry-binary-data
+  type: dfn; text: directory entry; url: directory
+  type: dfn; text: entry; url: entry
+  type: dfn; text: file entry; url: file
+  type: dfn; text: origin private file system; url: origin-private-file-system
 </pre>
 
 <style>
@@ -63,6 +69,16 @@ files and directories they've been given access to, allowing the web apps to
 later regain access to the same content without requiring the user to select the
 same file again.
 
+This API extends the API in [[FS]], which specifies an [=origin private file system=]
+which websites can get access to without having to first prompt the user for access.
+This enables use cases where a website wants to save data to disk before a user has
+picked a location to save to, without forcing the website to use a completely
+different storage mechanism with a different API for such files. It also makes it
+easier to write automated tests for code using this API. The entry point for this
+is the {{StorageManager/getDirectory()|navigator.storage.getDirectory()}} method.
+This is similar to the temporary file system as defined in earlier drafts of
+[[file-system-api|File API: Directories and System]].
+
 This API is similar to <a href="https://html.spec.whatwg.org/multipage/input.html#file-upload-state-(type=file)">`<input type=file>`</a>
 and <a href="https://wicg.github.io/entries-api/#html-forms">`<input type=file webkitdirectory>`</a>
 [[entries-api]]
@@ -70,36 +86,10 @@ in that user interaction happens through file and directory picker dialogs.
 Unlike those APIs, this API is currently purely a javascript API, and
 does not integrate with forms and/or input elements.
 
-Additionally this API also makes it possible for websites to get access to some
-directory without having to first prompt the user for access. This enables use
-cases where a website wants to save data to disk before a user has picked a
-location to save to, without forcing the website to use a completely different
-storage mechanism with a different API for such files. It also makes it easier
-to write automated tests for code using this API. The entry point for this is the
-{{StorageManager/getDirectory()|navigator.storage.getDirectory()}} method. This
-is similar to the temporary file system as defined in earlier drafts of
-[[file-system-api|File API: Directories and System]].
-
 # Files and Directories # {#files-and-directories}
 
 ## Concepts ## {#concepts}
 
-An <dfn>entry</dfn> is either a [=file entry=] or a [=directory entry=].
-
-Each [=/entry=] has an associated <dfn for=entry>name</dfn> (a [=string=]).
-
-A <dfn>valid file name</dfn> is a [=string=] that is not an empty string, is not equal to "." or "..",
-and does not contain '/' or any other character used as path separator on the underlying platform.
-
-Note: This means that '\' is not allowed in names on Windows, but might be allowed on
-other operating systems. Additionally underlying file systems might have further restrictions
-on what names are or aren't allowed, so a string merely being a [=valid file name=] is not
-a guarantee that creating a file or directory with that name will succeed.
-
-Issue: We should consider having further normative restrictions on file names that will
-never be allowed using this API, rather than leaving it entirely up to underlying file
-systems.
-
 A <dfn>valid suffix code point</dfn> is a [=code point=] that is [=ASCII alphanumeric=],
 U+002B (+), or U+002E (.).
 
@@ -108,59 +98,6 @@ majority of file extensions are purely alphanumeric, but compound extensions (su
 `.tar.gz`) and extensions such as `.c++` for C++ source code are also fairly common,
 hence the inclusion of + and . as allowed code points.
 
-A <dfn lt="file|file entry">file entry</dfn> additionally consists of
-<dfn for="file entry">binary data</dfn> (a [=byte sequence=]) and a
-<dfn for="file entry">modification timestamp</dfn> (a number representing the number of milliseconds since the <a spec=FileAPI>Unix Epoch</a>).
-
-A <dfn lt="directory|directory entry">directory entry</dfn> additionally consists of a [=/set=] of
-<dfn for="directory entry">children</dfn>, which are themselves [=/entries=]. Each member is either a [=/file=] or a [=directory=].
-
-An [=/entry=] |entry| should be [=list/contained=] in the [=children=] of at most one
-[=directory entry=], and that directory entry is also known as |entry|'s <dfn for=entry>parent</dfn>.
-An [=/entry=]'s [=entry/parent=] is null if no such directory entry exists.
-
-Note: Two different [=/entries=] can represent the same file or directory on disk, in which
-case it is possible for both entries to have a different parent, or for one entry to have a
-parent while the other entry does not have a parent. Typically an entry does not have a parent
-if it was returned by {{StorageManager/getDirectory()|navigator.storage.getDirectory()}}
-or one of the [=local file system handle factories=],
-and an entry will have a parent in all other cases.
-
-[=/Entries=] can (but don't have to) be backed by files on the host operating system's local file system,
-so it is possible for the [=binary data=], [=modification timestamp=],
-and [=children=] of entries to be modified by applications outside of this specification.
-Exactly how external changes are reflected in the data structures defined by this specification,
-as well as how changes made to the data structures defined here are reflected externally
-is left up to individual user-agent implementations.
-
-An [=/entry=] |a| is <dfn for="entry">the same as</dfn> an [=/entry=] |b| if |a| is equal to |b|, or
-if |a| and |b| are backed by the same file or directory on the local file system.
-
-Issue: TODO: Explain better how entries map to files on disk (multiple entries can map to the same file or
-directory on disk but an entry doesn't have to map to any file on disk).
-
-<div algorithm>
-To <dfn for="entry">resolve</dfn> an [=/entry=] |child| relative to a [=directory entry=] |root|,
-run the following steps:
-
-1. Let |result| be [=a new promise=].
-1. Run the following steps [=in parallel=]:
-  1. If |child| is [=the same as=] |root|,
-     [=/resolve=] |result| with an empty list, and abort.
-  1. Let |childPromises| be « ».
-  1. [=set/For each=] |entry| of |root|'s [=FileSystemHandle/entry=]'s [=children=]:
-    1. Let |p| be the result of [=entry/resolving=] |child| relative to |entry|.
-    1. [=list/Append=] |p| to |childPromises|.
-    1. [=Upon fulfillment=] of |p| with value |path|:
-      1. If |path| is not null:
-        1. [=list/Prepend=] |entry|'s [=entry/name=] to |path|.
-        1. [=/Resolve=] |result| with |path|.
-  1. [=Wait for all=] |childPromises|, with the following success steps:
-    1. If |result| hasn't been resolved yet, [=/resolve=] |result| with `null`.
-1. Return |result|.
-
-</div>
-
 ## Permissions ## {#permissions}
 
 The <dfn for=PermissionName enum-value>"file-system"</dfn> [=powerful feature=]'s
@@ -252,91 +189,13 @@ dictionary FileSystemHandlePermissionDescriptor {
   FileSystemPermissionMode mode = "read";
 };
 
-enum FileSystemHandleKind {
-  "file",
-  "directory",
-};
-
 [Exposed=(Window,Worker), SecureContext, Serializable]
-interface FileSystemHandle {
-  readonly attribute FileSystemHandleKind kind;
-  readonly attribute USVString name;
-
-  Promise<boolean> isSameEntry(FileSystemHandle other);
-
+partial interface FileSystemHandle {
   Promise<PermissionState> queryPermission(optional FileSystemHandlePermissionDescriptor descriptor = {});
   Promise<PermissionState> requestPermission(optional FileSystemHandlePermissionDescriptor descriptor = {});
 };
 </xmp>
 
-A {{FileSystemHandle}} object represents an [=/entry=]. Each {{FileSystemHandle}} object is associated
-with an <dfn for=FileSystemHandle>entry</dfn> (an [=/entry=]). Multiple separate objects implementing
-the {{FileSystemHandle}} interface can all be associated with the same [=/entry=] simultaneously.
-
-<div algorithm="serialization steps">
-{{FileSystemHandle}} objects are [=serializable objects=].
-
-Advisement: In the Origin Trial as available in Chrome 78, these objects are not yet serializable.
-In Chrome 82 they are.
-
-Their [=serialization steps=], given |value|, |serialized| and <var ignore>forStorage</var> are:
-
-1. Set |serialized|.\[[Origin]] to |value|'s [=relevant settings object=]'s [=environment settings object/origin=].
-1. Set |serialized|.\[[Entry]] to |value|'s [=FileSystemHandle/entry=].
-
-</div>
-
-<div algorithm="deserialization steps">
-Their [=deserialization steps=], given |serialized| and |value| are:
-
-1. If |serialized|.\[[Origin]] is not [=same origin=] with
-   |value|'s [=relevant settings object=]'s [=environment settings object/origin=],
-   then throw a {{DataCloneError}}.
-1. Set |value|'s [=FileSystemHandle/entry=] to |serialized|.\[[Entry]]
-
-</div>
-
-<div class="note domintro">
-  : |handle| . {{FileSystemHandle/kind}}
-  :: Returns {{FileSystemHandleKind/"file"}} if |handle| is a {{FileSystemFileHandle}},
-     or {{FileSystemHandleKind/"directory"}} if |handle| is a {{FileSystemDirectoryHandle}}.
-
-     This can be used to distinguish files from directories when iterating over the contents
-     of a directory.
-
-  : |handle| . {{FileSystemHandle/name}}
-  :: Returns the [=entry/name=] of the entry represented by |handle|.
-</div>
-
-The <dfn attribute for=FileSystemHandle>kind</dfn> attribute must
-return {{FileSystemHandleKind/"file"}} if the associated [=FileSystemHandle/entry=] is a [=file entry=],
-and return {{FileSystemHandleKind/"directory"}} otherwise.
-
-The <dfn attribute for=FileSystemHandle>name</dfn> attribute must return the [=entry/name=] of the
-associated [=FileSystemHandle/entry=].
-
-### The {{FileSystemHandle/isSameEntry()}} method ### {#api-filesystemhandle-issameentry}
-
-<div class="note domintro">
-  : <var ignore>same</var> = await |handle1| . {{FileSystemHandle/isSameEntry()|isSameEntry}}( |handle2| )
-  :: Returns true if |handle1| and |handle2| represent the same file or directory.
-</div>
-
-Advisement: This method is first available in Chrome 82.
-
-<div algorithm>
-The <dfn method for=FileSystemHandle>isSameEntry(|other|)</dfn> method, when invoked, must run these steps:
-
-1. Let |realm| be [=this=]'s [=relevant Realm=].
-1. Let |p| be [=a new promise=] in |realm|.
-1. Run the following steps [=in parallel=]:
-  1. If [=this=]'s [=FileSystemHandle/entry=] is [=the same as=] |other|'s [=FileSystemHandle/entry=],
-     [=/resolve=] |p| with `true`.
-  1. Else [=/resolve=] |p| with `false`.
-1. Return |p|.
-
-</div>
-
 ### The {{FileSystemHandle/queryPermission()}} method ### {#api-filesystemhandle-querypermission}
 
 <div class="note domintro">
@@ -408,738 +267,6 @@ The <dfn method for=FileSystemHandle>requestPermission(|descriptor|)</dfn> metho
 
 </div>
 
-## The {{FileSystemFileHandle}} interface ## {#api-filesystemfilehandle}
-
-<xmp class=idl>
-dictionary FileSystemCreateWritableOptions {
-  boolean keepExistingData = false;
-};
-
-[Exposed=(Window,Worker), SecureContext, Serializable]
-interface FileSystemFileHandle : FileSystemHandle {
-  Promise<File> getFile();
-  Promise<FileSystemWritableFileStream> createWritable(optional FileSystemCreateWritableOptions options = {});
-};
-</xmp>
-
-A {{FileSystemFileHandle}}'s associated [=FileSystemHandle/entry=] must be a [=file entry=].
-
-{{FileSystemFileHandle}} objects are [=serializable objects=]. Their [=serialization steps=] and
-[=deserialization steps=] are the same as those for {{FileSystemHandle}}.
-
-Advisement: In the Origin Trial as available in Chrome 78, these objects are not yet serializable.
-In Chrome 82 they are.
-
-### The {{FileSystemFileHandle/getFile()}} method ### {#api-filesystemfilehandle-getfile}
-
-<div class="note domintro">
-  : <var ignore>file</var> = await |fileHandle| . {{FileSystemFileHandle/getFile()}}
-  :: Returns a {{File}} representing the state on disk of the entry represented by |handle|.
-     If the file on disk changes or is removed after this method is called, the returned
-     {{File}} object will likely be no longer readable.
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemFileHandle>getFile()</dfn> method, when invoked, must run these steps:
-
-1. Let |result| be [=a new promise=].
-1. Run the following steps [=in parallel=]:
-  1. Let |permissionStatus| be the result of [=querying file system permission=]
-     given <b>[=this=]</b> and {{"read"}}.
-  1. If |permissionStatus| is not {{PermissionState/"granted"}},
-     reject |result| with a {{NotAllowedError}} and abort.
-  1. Let |entry| be <b>[=this=]</b>'s [=FileSystemHandle/entry=].
-  1. Let |f| be a new {{File}}.
-  1. Set |f|'s <a spec=FileAPI>snapshot state</a> to the current state of |entry|.
-  1. Set |f|'s underlying byte sequence to a copy of |entry|'s [=binary data=].
-  1. Initialize the value of |f|'s {{File/name}} attribute to |entry|'s [=entry/name=].
-  1. Initialize the value of |f|'s {{File/lastModified}} attribute to |entry|'s [=file entry/modification timestamp=].
-  1. Initialize the value of |f|'s {{Blob/type}} attribute to an implementation defined value, based on for example |entry|'s [=entry/name=] and/or its file extension.
-
-     Issue: The reading and snapshotting behavior needs to be better specified in the [[FILE-API]] spec,
-     for now this is kind of hand-wavy.
-  1. [=/Resolve=] |result| with |f|.
-1. Return |result|.
-
-</div>
-
-### The {{FileSystemFileHandle/createWritable()}} method ### {#api-filesystemfilehandle-createwritable}
-
-Advisement: In the Origin Trial as available in Chrome 82, createWritable replaces the createWriter method.
-
-<div class="note domintro">
-  : |stream| = await |fileHandle| . {{FileSystemFileHandle/createWritable()}}
-  : |stream| = await |fileHandle| . {{FileSystemFileHandle/createWritable()|createWritable}}({ {{FileSystemCreateWritableOptions/keepExistingData}}: true/false })
-  :: Returns a {{FileSystemWritableFileStream}} that can be used to write to the file. Any changes made through
-     |stream| won't be reflected in the file represented by |fileHandle| until the stream has been closed.
-     User agents try to ensure that no partial writes happen, i.e. the file represented by
-     |fileHandle| will either contain its old contents or it will contain whatever data was written
-     through |stream| up until the stream has been closed.
-
-     This is typically implemented by writing data to a temporary file, and only replacing the file
-     represented by |fileHandle| with the temporary file when the writable filestream is closed.
-
-     If {{FileSystemCreateWritableOptions/keepExistingData}} is `false` or not specified,
-     the temporary file starts out empty,
-     otherwise the existing file is first copied to this temporary file.
-</div>
-
-Issue(67): There has been some discussion around and desire for a "inPlace" mode for createWritable
-(where changes will be written to the actual underlying file as they are written to the writer, for
-example to support in-place modification of large files or things like databases). This is not
-currently implemented in Chrome. Implementing this is currently blocked on figuring out how to
-combine the desire to run malware checks with the desire to let websites make fast in-place
-modifications to existing large files.
-
-<div algorithm>
-The <dfn method for=FileSystemFileHandle>createWritable(|options|)</dfn> method, when invoked, must run these steps:
-
-1. Let |result| be [=a new promise=].
-1. Run the following steps [=in parallel=]:
-  1. Let |permissionStatus| be the result of [=requesting file system permission=]
-     given <b>[=this=]</b> and {{"readwrite"}}.
-     If that throws an exception, [=reject=] |result| with that exception and abort.
-  1. If |permissionStatus| is not {{PermissionState/"granted"}},
-     reject |result| with a {{NotAllowedError}} and abort.
-  1. Let |entry| be <b>[=this=]</b>'s [=FileSystemHandle/entry=].
-  1. Let |stream| be the result of [=create a new FileSystemWritableFileStream|creating a new FileSystemWritableFileStream=]
-     for |entry| in <b>[=this=]</b>'s [=relevant realm=].
-  1. If |options|.{{FileSystemCreateWritableOptions/keepExistingData}} is `true`:
-    1. Set |stream|.[=[[buffer]]=] to a copy of |entry|'s [=file entry/binary data=].
-  1. [=/Resolve=] |result| with |stream|.
-1. Return |result|.
-
-</div>
-
-## The {{FileSystemDirectoryHandle}} interface ## {#api-filesystemdirectoryhandle}
-
-<xmp class=idl>
-dictionary FileSystemGetFileOptions {
-  boolean create = false;
-};
-
-dictionary FileSystemGetDirectoryOptions {
-  boolean create = false;
-};
-
-dictionary FileSystemRemoveOptions {
-  boolean recursive = false;
-};
-
-[Exposed=(Window,Worker), SecureContext, Serializable]
-interface FileSystemDirectoryHandle : FileSystemHandle {
-  async iterable<USVString, FileSystemHandle>;
-
-  Promise<FileSystemFileHandle> getFileHandle(USVString name, optional FileSystemGetFileOptions options = {});
-  Promise<FileSystemDirectoryHandle> getDirectoryHandle(USVString name, optional FileSystemGetDirectoryOptions options = {});
-
-  Promise<undefined> removeEntry(USVString name, optional FileSystemRemoveOptions options = {});
-
-  Promise<sequence<USVString>?> resolve(FileSystemHandle possibleDescendant);
-};
-</xmp>
-
-A {{FileSystemDirectoryHandle}}'s associated [=FileSystemHandle/entry=] must be a [=directory entry=].
-
-{{FileSystemDirectoryHandle}} objects are [=serializable objects=]. Their [=serialization steps=] and
-[=deserialization steps=] are the same as those for {{FileSystemHandle}}.
-
-Advisement: In the Origin Trial as available in Chrome 78, these objects are not yet serializable.
-In Chrome 82 they are.
-
-Advisement: In Chrome versions upto Chrome 85 `getFileHandle` and `getDirectoryHandle` where
-called `getFile` and `getDirectory` instead.
-
-### Directory iteration ### {#api-filesystemdirectoryhandle-asynciterable}
-
-<div class="note domintro">
-  : for await (let [|name|, |handle|] of |directoryHandle|) {}
-  : for await (let [|name|, |handle|] of |directoryHandle| . entries()) {}
-  : for await (let |handle| of |directoryHandle| . values()) {}
-  : for await (let |name| of |directoryHandle| . keys()) {}
-  :: Iterates over all entries whose parent is the entry represented by |directoryHandle|. Entries
-     that are created or deleted while the iteration is in progress might or might not be included.
-     No guarantees are given either way.
-</div>
-
-Advisement: In Chrome this is currently implemented as a `directoryHandle.getEntries()` method that can be used in a `for await..of` loop.
-This `getEntries()` method returns more or less the same async iterable as what is returned by `values()` in this specification.
-The proper async iterable declaration is not yet implemented.
-
-Issue(173): In the future we might want to add arguments to the async iterable declaration to
-support for example recursive iteration.
-
-<div algorithm="iterator initialization">
-The [=asynchronous iterator initialization steps=] for a {{FileSystemDirectoryHandle}} |handle|
-ant its async iterator |iterator| are:
-
-1. Let |permissionStatus| be the result of [=querying file system permission=]
-   given |handle| and {{"read"}}.
-
-1. If |permissionStatus| is not {{PermissionState/"granted"}},
-   throw a {{NotAllowedError}}.
-
-1. Set |iterator|'s <dfn for="FileSystemDirectoryHandle-iterator">past results</dfn> to an empty [=/set=].
-
-</div>
-
-<div algorithm="next iteration result">
-To [=get the next iteration result=] for a {{FileSystemDirectoryHandle}} |handle|
-and its async iterator |iterator|:
-
-1. Let |promise| be [=a new promise=].
-
-1. Let |directory| be |handle|'s [=FileSystemHandle/entry=].
-
-1. Let |permissionStatus| be the result of [=querying file system permission=]
-   given |handle| and {{"read"}}.
-
-1. If |permissionStatus| is not {{PermissionState/"granted"}},
-   reject |promise| with a {{NotAllowedError}} and return |promise|.
-
-1. Let |child| be an [=/entry=] in |directory|'s [=directory entry/children=],
-   such that |child|'s [=entry/name=] is not contained in |iterator|'s [=past results=],
-   or `null` if no such entry exists.
-
-   Note: This is intentionally very vague about the iteration order. Different platforms
-   and file systems provide different guarantees about iteration order, and we want it to
-   be possible to efficiently implement this on all platforms. As such no guarantees are given
-   about the exact order in which elements are returned.
-
-1. If |child| is `null`, then:
-  1. [=/Resolve=] |promise| with `undefined`.
-
-1. Otherwise:
-  1. [=set/Append=] |child|'s [=entry/name=] to |iterator|'s [=past results=].
-  1. If |child| is a [=file entry=]:
-    1. Let |result| be a new {{FileSystemFileHandle}} associated with |child|.
-  1. Otherwise:
-    1. Let |result| be a new {{FileSystemDirectoryHandle}} associated with |child|.
-  1. [=/Resolve=] |promise| with (|child|'s [=entry/name=], |result|).
-
-1. Return |promise|.
-
-</div>
-
-### The {{FileSystemDirectoryHandle/getFileHandle()}} method ### {#api-filesystemdirectoryhandle-getfilehandle}
-
-<div class="note domintro">
-  : |fileHandle| = await |directoryHandle| . {{FileSystemDirectoryHandle/getFileHandle()|getFileHandle}}(|name|)
-  : |fileHandle| = await |directoryHandle| . {{FileSystemDirectoryHandle/getFileHandle()|getFileHandle}}(|name|, { {{FileSystemGetFileOptions/create}}: false })
-  :: Returns a handle for a file named |name| in the directory represented by |directoryHandle|. If
-     no such file exists, this rejects.
-
-  : |fileHandle| = await |directoryHandle| . {{FileSystemDirectoryHandle/getFileHandle()|getFileHandle}}(|name|, { {{FileSystemGetFileOptions/create}}: true })
-  :: Returns a handle for a file named |name| in the directory represented by |directoryHandle|. If
-     no such file exists, this creates a new file. If no file with named |name| can be created this
-     rejects. Creation can fail because there already is a directory with the same name, because the
-     name uses characters that aren't supported in file names on the underlying file system, or
-     because the user agent for security reasons decided not to allow creation of the file.
-
-     This operation requires write permission, even if the file being returned already exists. If
-     this handle doesn't already have write permission, this could result in a prompt being shown to
-     the user. To get an existing file without needing write permission, call this method
-     with <code>{ {{FileSystemGetFileOptions/create}}: false }</code>.
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemDirectoryHandle>getFileHandle(|name|, |options|)</dfn> method, when invoked,
-must run these steps:
-
-1. Let |result| be [=a new promise=].
-1. Run the following steps [=in parallel=]:
-  1. If |name| is not a [=valid file name=], [=/reject=] |result| with a {{TypeError}} and abort.
-
-  1. Let |entry| be <b>[=this=]</b>'s [=FileSystemHandle/entry=].
-  1. If |options|.{{FileSystemGetFileOptions/create}} is `true`:
-    1. Let |permissionStatus| be the result of [=requesting file system permission=]
-       given <b>[=this=]</b> and {{"readwrite"}}.
-       If that throws an exception, [=reject=] |result| with that exception and abort.
-  1. Otherwise:
-    1. Let |permissionStatus| be the result of [=querying file system permission=]
-       given <b>[=this=]</b> and {{"read"}}.
-  1. If |permissionStatus| is not {{PermissionState/"granted"}},
-     reject |result| with a {{NotAllowedError}} and abort.
-
-  1. [=set/For each=] |child| of |entry|'s [=directory entry/children=]:
-    1. If |child|'s [=entry/name=] equals |name|:
-      1. If |child| is a [=directory entry=]:
-        1. [=/Reject=] |result| with a {{TypeMismatchError}} and abort.
-      1. [=/Resolve=] |result| with a new {{FileSystemFileHandle}} whose [=FileSystemHandle/entry=] is |child| and abort.
-  1. If |options|.{{FileSystemGetFileOptions/create}} is `false`:
-    1. [=/Reject=] |result| with a {{NotFoundError}} and abort.
-  1. Let |child| be a new [=file entry=].
-  1. Set |child|'s [=entry/name=] to |name|.
-  1. Set |child|'s [=binary data=] to an empty [=byte sequence=].
-  1. Set |child|'s [=modification timestamp=] to the current time.
-  1. [=set/Append=] |child| to |entry|'s [=directory entry/children=].
-  1. If creating |child| in the underlying file system throws an exception,
-     [=/reject=] |result| with that exception and abort.
-
-     Issue(68): Better specify what possible exceptions this could throw.
-  1. [=/Resolve=] |result| with a new {{FileSystemFileHandle}} whose [=FileSystemHandle/entry=] is |child|.
-1. Return |result|.
-
-</div>
-
-### The {{FileSystemDirectoryHandle/getDirectoryHandle()}} method ### {#api-filesystemdirectoryhandle-getdirectoryhandle}
-
-<div class="note domintro">
-  : |subdirHandle| = await |directoryHandle| . {{FileSystemDirectoryHandle/getDirectoryHandle()|getDirectoryHandle}}(|name|)
-  : |subdirHandle| = await |directoryHandle| . {{FileSystemDirectoryHandle/getDirectoryHandle()|getDirectoryHandle}}(|name|, { {{FileSystemGetDirectoryOptions/create}}: false })
-  :: Returns a handle for a directory named |name| in the directory represented by
-    |directoryHandle|. If no such directory exists, this rejects.
-
-  : |subdirHandle| = await |directoryHandle| . {{FileSystemDirectoryHandle/getDirectoryHandle()|getDirectoryHandle}}(|name|, { {{FileSystemGetDirectoryOptions/create}}: true })
-  :: Returns a handle for a directory named |name| in the directory represented by
-     |directoryHandle|. If no such directory exists, this creates a new directory. If creating the
-     directory failed, this rejects. Creation can fail because there already is a file with the same
-     name, or because the name uses characters that aren't supported in file names on the underlying
-     file system.
-
-     This operation requires write permission, even if the directory being returned already exists.
-     If this handle doesn't already have write permission, this could result in a prompt being shown
-     to the user. To get an existing directory without needing write permission, call this method
-     with <code>{ {{FileSystemGetDirectoryOptions/create}}: false }</code>.
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemDirectoryHandle>getDirectoryHandle(|name|, |options|)</dfn> method, when
-invoked, must run these steps:
-
-1. Let |result| be [=a new promise=].
-1. Run the following steps [=in parallel=]:
-  1. If |name| is not a [=valid file name=], [=/reject=] |result| with a {{TypeError}} and abort.
-
-  1. Let |entry| be <b>[=this=]</b>'s [=FileSystemHandle/entry=].
-  1. If |options|.{{FileSystemGetDirectoryOptions/create}} is `true`:
-    1. Let |permissionStatus| be the result of [=requesting file system permission=]
-       given <b>[=this=]</b> and {{"readwrite"}}.
-       If that throws an exception, [=reject=] |result| with that exception and abort.
-  1. Otherwise:
-    1. Let |permissionStatus| be the result of [=querying file system permission=]
-       given <b>[=this=]</b> and {{"read"}}.
-  1. If |permissionStatus| is not {{PermissionState/"granted"}},
-     reject |result| with a {{NotAllowedError}} and abort.
-
-  1. [=set/For each=] |child| of |entry|'s [=directory entry/children=]:
-    1. If |child|'s [=entry/name=] equals |name|:
-      1. If |child| is a [=file entry=]:
-        1. [=/Reject=] |result| with a {{TypeMismatchError}} and abort.
-      1. [=/Resolve=] |result| with a new {{FileSystemDirectoryHandle}} whose [=FileSystemHandle/entry=] is |child| and abort.
-  1. If |options|.{{FileSystemGetFileOptions/create}} is `false`:
-    1. [=/Reject=] |result| with a {{NotFoundError}} and abort.
-  1. Let |child| be a new [=directory entry=].
-  1. Set |child|'s [=entry/name=] to |name|.
-  1. Set |child|'s [=directory entry/children=] to an empty [=/set=].
-  1. [=set/Append=] |child| to |entry|'s [=directory entry/children=].
-  1. If creating |child| in the underlying file system throws an exception,
-     [=/reject=] |result| with that exception and abort.
-
-     Issue(68): Better specify what possible exceptions this could throw.
-  1. [=/Resolve=] |result| with a new {{FileSystemDirectoryHandle}} whose [=FileSystemHandle/entry=] is |child|.
-1. Return |result|.
-
-</div>
-
-### The {{FileSystemDirectoryHandle/removeEntry()}} method ### {#api-filesystemdirectoryhandle-removeentry}
-
-<div class="note domintro">
-  : await |directoryHandle| . {{FileSystemDirectoryHandle/removeEntry()|removeEntry}}(|name|)
-  : await |directoryHandle| . {{FileSystemDirectoryHandle/removeEntry()|removeEntry}}(|name|, { {{FileSystemRemoveOptions/recursive}}: false })
-  :: If the directory represented by |directoryHandle| contains a file named |name|, or an empty
-     directory named |name|, this will attempt to delete that file or directory.
-
-     Attempting to delete a file or directory that does not exist is considered success,
-     while attempting to delete a non-empty directory will result in a promise rejection.
-
-  : await |directoryHandle| . {{FileSystemDirectoryHandle/removeEntry()|removeEntry}}(|name|, { {{FileSystemRemoveOptions/recursive}}: true })
-  :: Removes the entry named |name| in the directory represented by |directoryHandle|.
-     If that entry is a directory, its contents will also be deleted recursively.
-     recursively.
-
-     Attempting to delete a file or directory that does not exist is considered success.
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemDirectoryHandle>removeEntry(|name|, |options|)</dfn> method, when invoked, must run
-these steps:
-
-1. Let |result| be [=a new promise=].
-1. Run the following steps [=in parallel=]:
-  1. If |name| is not a [=valid file name=], [=/reject=] |result| with a {{TypeError}} and abort.
-
-  1. Let |entry| be <b>[=this=]</b>'s [=FileSystemHandle/entry=].
-  1. Let |permissionStatus| be the result of [=requesting file system permission=]
-     given <b>[=this=]</b> and {{"readwrite"}}.
-     If that throws an exception, [=reject=] |result| with that exception and abort.
-  1. If |permissionStatus| is not {{PermissionState/"granted"}},
-     reject |result| with a {{NotAllowedError}} and abort.
-
-  1. [=set/For each=] |child| of |entry|'s [=directory entry/children=]:
-    1. If |child|'s [=entry/name=] equals |name|:
-      1. If |child| is a [=directory entry=]:
-        1. If |child|'s [=directory entry/children=] is not [=set/is empty|empty=] and |options|.{{FileSystemRemoveOptions/recursive}} is `false`:
-          1. [=/Reject=] |result| with an {{InvalidModificationError}} and abort.
-      1. [=set/Remove=] |child| from |entry|'s [=directory entry/children=].
-      1. If removing |child| in the underlying file system throws an exception,
-         [=/reject=] |result| with that exception and abort.
-
-         Note: If {{FileSystemRemoveOptions/recursive}} is `true`, the removal can fail
-         non-atomically. Some files or directories might have been removed while other files
-         or directories still exist.
-
-         Issue(68): Better specify what possible exceptions this could throw.
-      1. [=/Resolve=] |result| with `undefined`.
-  1. [=/Reject=] |result| with a {{NotFoundError}}.
-1. Return |result|.
-
-
-</div>
-
-### The {{FileSystemDirectoryHandle/resolve()}} method ### {#api-filesystemdirectoryhandle-resolve}
-
-<div class="note domintro">
-  : |path| = await |directory| . {{FileSystemDirectoryHandle/resolve()|resolve}}( |child| )
-  :: If |child| is equal to |directory|, |path| will be an empty array.
-  :: If |child| is a direct child of |directory|, |path| will be an array containing |child|'s name.
-  :: If |child| is a descendant of |directory|, |path| will be an array containing the names of
-     all the intermediate directories and |child|'s name as last element.
-     For example if |directory| represents `/home/user/project`
-     and |child| represents `/home/user/project/foo/bar`, this will return
-     `['foo', 'bar']`.
-  :: Otherwise (|directory| and |child| are not related), |path| will be null.
-
-     This functionality can be useful if a web application shows a directory
-     listing to highlight a file opened through a file picker in that directory listing.
-</div>
-
-Advisement: This method is first available in Chrome 82.
-
-<div class=example id=filesystemdirectoryhandle-resolve-example>
-<xmp highlight=js>
-// Assume we at some point got a valid directory handle.
-const dir_ref = current_project_dir;
-if (!dir_ref) return;
-
-// Now get a file reference by showing a file picker:
-const file_ref = await showOpenFilePicker();
-if (!file_ref) {
-    // User cancelled, or otherwise failed to open a file.
-    return;
-}
-
-// Check if file_ref exists inside dir_ref:
-const relative_path = await dir_ref.resolve(file_ref);
-if (relative_path === null) {
-    // Not inside dir_ref
-} else {
-    // relative_path is an array of names, giving the relative path
-    // from dir_ref to the file that is represented by file_ref:
-    assert relative_path.pop() === file_ref.name;
-
-    let entry = dir_ref;
-    for (const name of relative_path) {
-        entry = await entry.getDirectoryHandle(name);
-    }
-    entry = await entry.getFileHandle(file_ref.name);
-
-    // Now |entry| will represent the same file on disk as |file_ref|.
-    assert await entry.isSameEntry(file_ref) === true;
-}
-</xmp>
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemDirectoryHandle>resolve(|possibleDescendant|)</dfn> method,
-when invoked, must return the result of [=entry/resolving=]
-|possibleDescendant|'s [=FileSystemHandle/entry=] relative to [=this=]'s [=FileSystemHandle/entry=].
-
-</div>
-
-
-
-## The {{FileSystemWritableFileStream}} interface ## {#api-filesystemwritablefilestream}
-
-<xmp class=idl>
-enum WriteCommandType {
-  "write",
-  "seek",
-  "truncate",
-};
-
-dictionary WriteParams {
-  required WriteCommandType type;
-  unsigned long long? size;
-  unsigned long long? position;
-  (BufferSource or Blob or USVString)? data;
-};
-
-typedef (BufferSource or Blob or USVString or WriteParams) FileSystemWriteChunkType;
-
-[Exposed=(Window,Worker), SecureContext]
-interface FileSystemWritableFileStream : WritableStream {
-  Promise<undefined> write(FileSystemWriteChunkType data);
-  Promise<undefined> seek(unsigned long long position);
-  Promise<undefined> truncate(unsigned long long size);
-};
-</xmp>
-
-A {{FileSystemWritableFileStream}} has an associated <dfn for=FileSystemWritableFileStream>\[[file]]</dfn> (a [=file entry=]).
-
-A {{FileSystemWritableFileStream}} has an associated <dfn for=FileSystemWritableFileStream>\[[buffer]]</dfn> (a [=byte sequence=]).
-It is initially empty.
-
-Note: This buffer can get arbitrarily large, so it is expected that implementations will not keep this in memory,
-but instead use a temporary file for this. All access to \[[buffer]] is done in promise returning methods and
-algorithms, so even though operations on it seem sync, implementations can implement them async.
-
-A {{FileSystemWritableFileStream}} has an associated <dfn for=FileSystemWritableFileStream>\[[seekOffset]]</dfn> (a number).
-It is initially 0.
-
-<div class="note domintro">
-A {{FileSystemWritableFileStream}} object is a {{WritableStream}} object with additional
-convenience methods, which operates on a single file on disk.
-
-Upon creation, an underlying sink will have been created and the stream will be usable.
-All operations executed on the stream are queuable and producers will be able to respond to backpressure.
-
-The underlying sink's write method, and therefore {{WritableStreamDefaultWriter/write()|WritableStreamDefaultWriter's write()}}
-method, will accept byte-like data or {{WriteParams}} as input.
-
-The {{FileSystemWritableFileStream}} has a file position cursor initialized at byte offset 0 from the top of the file.
-When using {{FileSystemWritableFileStream/write()|write()}} or by using WritableStream capabilities through the {{WritableStreamDefaultWriter/write()|WritableStreamDefaultWriter's write()}} method, this position will be advanced based on the number of bytes written through the stream object.
-
-Similarly, when piping a {{ReadableStream}} into a {{FileSystemWritableFileStream}} object, this position is updated with the number of bytes that passed through the stream.
-
-{{WritableStream/getWriter()|getWriter()}} returns an instance of {{WritableStreamDefaultWriter}}.
-</div>
-
-<div algorithm>
-To <dfn>create a new FileSystemWritableFileStream</dfn> given a [=file entry=] |file|
-in a [=/Realm=] |realm|, perform the following steps:
-
-1. Let |stream| be a [=new=] {{FileSystemWritableFileStream}} in |realm|.
-1. Set |stream|.[=FileSystemWritableFileStream/[[file]]=] to |file|.
-1. Let |writeAlgorithm| be an algorithm which takes a |chunk| argument
-   and returns the result of running the [=write a chunk=] algorithm with |stream| and |chunk|.
-1. Let |closeAlgorithm| be the following steps:
-   1. Let |closeResult| be [=a new promise=].
-   1. Run the following steps [=in parallel=]:
-      1. Let |permissionStatus| be the [=permission state=] for a {{FileSystemPermissionDescriptor}}
-         with {{FileSystemPermissionDescriptor/handle}} representing |stream|.[=[[file]]=],
-         and {{FileSystemPermissionDescriptor/mode}} = {{"readwrite"}}.
-      1. If |permissionStatus| is not {{PermissionState/"granted"}},
-         reject |closeResult| with a {{NotAllowedError}} and abort.
-      1. Perform user agent-specific [=malware scans and safe browsing checks=].
-         If these checks fail, [=/reject=] |closeResult| with an {{AbortError}} and abort.
-      1. Set |stream|.[=[[file]]=]'s [=file entry/binary data=] to |stream|.[=[[buffer]]=].
-         If that throws an exception, [=/reject=] |closeResult| with that exception and abort.
-
-         Note: It is expected that this atomically updates the contents of the file on disk
-         being written to.
-      1. [=/Resolve=] |closeResult| with `undefined`.
-   1. Return |closeResult|.
-1. Let |highWaterMark| be 1.
-1. Let |sizeAlgorithm| be an algorithm that returns `1`.
-1. [=WritableStream/Set up=] |stream| with <a for="WritableStream/set up"><var
-   ignore>writeAlgorithm</var></a> set to |writeAlgorithm|, <a for="WritableStream/set up"><var
-   ignore>closeAlgorithm</var></a> set to |closeAlgorithm|, <a for="WritableStream/set up"><var
-   ignore>highWaterMark</var></a> set to |highWaterMark|, and <a for="WritableStream/set up"><var
-   ignore>sizeAlgorithm</var></a> set to |sizeAlgorithm|.
-1. Return |stream|.
-
-</div>
-
-<div algorithm>
-The <dfn>write a chunk</dfn> algorithm,
-given a {{FileSystemWritableFileStream}} |stream| and |chunk|,
-runs these steps:
-
-1. Let |input| be the result of [=converting=] |chunk| to a {{FileSystemWriteChunkType}}.
-   If this throws an exception, then return [=a promise rejected with=] that exception.
-1. Let |p| be [=a new promise=].
-1. Run the following steps [=in parallel=]:
-   1. Let |permissionStatus| be the [=permission state=] for a {{FileSystemPermissionDescriptor}}
-      with {{FileSystemPermissionDescriptor/handle}} representing |stream|.[=[[file]]=],
-      and {{FileSystemPermissionDescriptor/mode}} = {{"readwrite"}}.
-   1. If |permissionStatus| is not {{PermissionState/"granted"}},
-      reject |p| with a {{NotAllowedError}} and abort.
-   1. Let |command| be |input|.{{WriteParams/type}} if |input| is a {{WriteParams}},
-      and {{WriteCommandType/"write"}} otherwise.
-   1. If |command| is {{WriteCommandType/"write"}}:
-      1. Let |data| be |input|.{{WriteParams/data}} if |input| is a {{WriteParams}},
-         and |input| otherwise.
-      1. If |data| is `undefined`,
-         reject |p| with a {{TypeError}} and abort.
-      1. Let |writePosition| be |stream|.[=[[seekOffset]]=].
-      1. If |input| is a {{WriteParams}} and |input|.{{WriteParams/position}} is not `undefined`,
-         set |writePosition| to |input|.{{WriteParams/position}}.
-      1. Let |oldSize| be |stream|.[=[[buffer]]=]'s [=byte sequence/length=].
-      1. If |data| is a {{BufferSource}},
-         let |dataBytes| be [=get a copy of the buffer source|a copy of=] |data|.
-      1. Else if |data| is a {{Blob}}:
-         1. Let |dataBytes| be the result of performing the
-            <a spec=FileAPI>read operation</a> on |data|.
-            If this throws an exception, [=/reject=] |p| with that exception and abort.
-      1. Else:
-         1. [=Assert=]: |data| is a {{USVString}}.
-         1. Let |dataBytes| be the result of [=UTF-8 encoding=] |data|.
-      1. If |writePosition| is larger than |oldSize|,
-         append |writePosition| - |oldSize| `0x00` (NUL) bytes to the end of |stream|.[=[[buffer]]=].
-
-         Note: Implementations are expected to behave as if the skipped over file contents
-         are indeed filled with NUL bytes. That doesn't mean these bytes have to actually be
-         written to disk and take up disk space. Instead most file systems support so called
-         sparse files, where these NUL bytes don't take up actual disk space.
-
-      1. Let |head| be a [=byte sequence=] containing the first |writePosition| bytes of |stream|.[=[[buffer]]=].
-      1. Let |tail| be an empty [=byte sequence=].
-      1. If |writePosition| + |data|.[=byte sequence/length=] is smaller than |oldSize|:
-         1. Let |tail| be a [=byte sequence=] containing the last
-            |oldSize| - (|writePosition| + |data|.[=byte sequence/length=]) bytes of |stream|.[=[[buffer]]=].
-      1. Set |stream|.[=[[buffer]]=] to the concatenation of |head|, |data| and |tail|.
-      1. If the operations modifying |stream|.[=[[buffer]]=] in the previous steps failed
-         due to exceeding the [=storage quota=], [=/reject=] |p| with a {{QuotaExceededError}} and abort,
-         leaving |stream|.[=[[buffer]]=] unmodified.
-
-         Note: [=Storage quota=] only applies to files stored in the [=origin private file system=].
-         However this operation could still fail for other files, for example if the disk being written
-         to runs out of disk space.
-      1. Set |stream|.[=[[seekOffset]]=] to |writePosition| + |data|.[=byte sequence/length=].
-      1. [=/Resolve=] |p|.
-   1. Else if |command| is {{WriteCommandType/"seek"}}:
-      1. If |chunk|.{{WriteParams/position}} is `undefined`,
-         [=/reject=] |p| with a {{TypeError}} and abort.
-      1. Set |stream|.[=[[seekOffset]]=] to |chunk|.{{WriteParams/position}}.
-      1. [=/Resolve=] |p|.
-   1. Else if |command| is {{WriteCommandType/"truncate"}}:
-      1. If |chunk|.{{WriteParams/size}} is `undefined`,
-         [=/reject=] |p| with a {{TypeError}} and abort.
-      1. Let |newSize| be |chunk|.{{WriteParams/size}}.
-      1. Let |oldSize| be |stream|.[=[[buffer]]=]'s [=byte sequence/length=].
-      1. If |newSize| is larger than |oldSize|:
-         1. Set |stream|.[=[[buffer]]=] to a [=byte sequence=] formed by concating
-            |stream|.[=[[buffer]]=] with a [=byte sequence=] containing |newSize|-|oldSize| `0x00` bytes.
-         1. If the operation in the previous step failed due to exceeding the [=storage quota=],
-            [=/reject=] |p| with a {{QuotaExceededError}} and abort,
-            leaving |stream|.[=[[buffer]]=] unmodified.
-
-            Note: [=Storage quota=] only applies to files stored in the [=origin private file system=].
-            However this operation could still fail for other files, for example if the disk being written
-            to runs out of disk space.
-      1. Else if |newSize| is smaller than |oldSize|:
-         1. Set |stream|.[=[[buffer]]=] to a [=byte sequence=] containing the first |newSize| bytes
-            in |stream|.[=[[buffer]]=].
-      1. If |stream|.[=[[seekOffset]]=] is bigger than |newSize|,
-         set |stream|.[=[[seekOffset]]=] to |newSize|.
-      1. [=/Resolve=] |p|.
-1. Return |p|.
-
-</div>
-
-### The {{FileSystemWritableFileStream/write()}} method ### {#api-filesystemwritablefilestream-write}
-
-<div class="note domintro">
-  : await |stream| . {{FileSystemWritableFileStream/write()|write}}(|data|)
-  : await |stream| . {{FileSystemWritableFileStream/write()|write}}({
-      {{WriteParams/type}}: {{WriteCommandType/"write"}},
-      {{WriteParams/data}}: |data| })
-  :: Writes the content of |data| into the file associated with |stream| at the current file
-     cursor offset.
-
-     No changes are written to the actual file on disk until the stream has been closed.
-     Changes are typically written to a temporary file instead.
-
-  : await |stream| . {{FileSystemWritableFileStream/write()|write}}({
-      {{WriteParams/type}}: {{WriteCommandType/"write"}},
-      {{WriteParams/position}}: |position|,
-      {{WriteParams/data}}: |data| })
-  :: Writes the content of |data| into the file associated with |stream| at |position|
-     bytes from the top of the file. Also updates the current file cursor offset to the
-     end of the written data.
-
-     No changes are written to the actual file on disk until the stream has been closed.
-     Changes are typically written to a temporary file instead.
-
-  : await |stream| . {{FileSystemWritableFileStream/write()|write}}({
-      {{WriteParams/type}}: {{WriteCommandType/"seek"}},
-      {{WriteParams/position}}: |position| })
-  :: Updates the current file cursor offset the |position| bytes from the top of the file.
-
-  : await |stream| . {{FileSystemWritableFileStream/write()|write}}({
-      {{WriteParams/type}}: {{WriteCommandType/"truncate"}},
-      {{WriteParams/size}}: |size| })
-  :: Resizes the file associated with |stream| to be |size| bytes long. If |size| is larger than
-     the current file size this pads the file with null bytes, otherwise it truncates the file.
-
-     The file cursor is updated when {{truncate}} is called. If the offset is smaller than offset,
-     it remains unchanged. If the offset is larger than |size|, the offset is set to |size| to
-     ensure that subsequent writes do not error.
-
-     No changes are written to the actual file until on disk until the stream has been closed.
-     Changes are typically written to a temporary file instead.
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemWritableFileStream>write(|data|)</dfn> method, when invoked, must run
-these steps:
-
-1. Let |writer| be the result of [=WritableStream/getting a writer=] for [=this=].
-1. Let |result| be the result of [=WritableStreamDefaultWriter/writing a chunk=] to |writer| given
-   |data|.
-1. [=WritableStreamDefaultWriter/Release=] |writer|.
-1. Return |result|.
-
-</div>
-
-### The {{FileSystemWritableFileStream/seek()}} method ### {#api-filesystemwritablefilestream-seek}
-
-<div class="note domintro">
-  : await |stream| . {{FileSystemWritableFileStream/seek()|seek}}(|position|)
-  :: Updates the current file cursor offset the |position| bytes from the top of the file.
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemWritableFileStream>seek(|position|)</dfn> method, when invoked, must run these
-steps:
-
-1. Let |writer| be the result of [=WritableStream/getting a writer=] for [=this=].
-1. Let |result| be the result of [=WritableStreamDefaultWriter/writing a chunk=] to |writer| given
-    «[ "{{WriteParams/type}}" → {{WriteCommandType/"seek"}}, "{{WriteParams/position}}" →
-    |position| ]».
-1. [=WritableStreamDefaultWriter/Release=] |writer|.
-1. Return |result|.
-
-</div>
-
-### The {{FileSystemWritableFileStream/truncate()}} method ### {#api-filesystemwritablefilestream-truncate}
-
-<div class="note domintro">
-  : await |stream| . {{FileSystemWritableFileStream/truncate()|truncate}}(|size|)
-  :: Resizes the file associated with |stream| to be |size| bytes long. If |size| is larger than
-     the current file size this pads the file with null bytes, otherwise it truncates the file.
-
-     The file cursor is updated when {{truncate}} is called. If the offset is smaller than offset,
-     it remains unchanged. If the offset is larger than |size|, the offset is set to |size| to
-     ensure that subsequent writes do not error.
-
-     No changes are written to the actual file until on disk until the stream has been closed.
-     Changes are typically written to a temporary file instead.
-</div>
-
-<div algorithm>
-The <dfn method for=FileSystemWritableFileStream>truncate(|size|)</dfn> method, when invoked, must run these
-steps:
-
-1. Let |writer| be the result of [=WritableStream/getting a writer=] for [=this=].
-1. Let |result| be the result of [=WritableStreamDefaultWriter/writing a chunk=] to |writer| given
-    «[ "{{WriteParams/type}}" → {{WriteCommandType/"truncate"}}, "{{WriteParams/size}}" →
-    |size| ]».
-1. [=WritableStreamDefaultWriter/Release=] |writer|.
-1. Return |result|.
-
-</div>
 
 # Accessing Local File System # {#local-filesystem}
 
@@ -1482,7 +609,7 @@ run the following steps:
   1. Let |entry| be |startIn|'s [=FileSystemHandle/entry=].
   1. If |entry| does not represent an [=/entry=] in an [=origin private file system=]:
     1. If |entry| is a [=file entry=], and a path on the local file system
-       corresponding to the parent directory if |entry| can be determined,
+       corresponding to the parent directory of |entry| can be determined,
        then return that path.
     1. If |entry| is a [=directory entry=], and a path on the local file system
        corresponding to |entry| can be determined,
@@ -1832,61 +959,6 @@ Issue: This currently does not block access to [=too sensitive or dangerous=] di
 be consistent with other APIs that give access to dropped files and directories. This is inconsistent
 with the [=local file system handle factories=] though, so we might want to reconsider this.
 
-# Accessing the Origin Private File System # {#sandboxed-filesystem}
-
-The <dfn>origin private file system</dfn> is a [=storage endpoint=] whose
-<a spec=storage for="storage endpoint">identifier</a> is `"fileSystem"`,
-<a spec=storage for="storage endpoint">types</a> are `« "local" »`,
-and <a spec=storage for="storage endpoint">quota</a> is null.
-
-Issue: Storage endpoints should be defined in [[storage]] itself, rather
-than being defined here. So merge this into the table there.
-
-Note: While user agents will typically implement this by persisting the contents of this
-[=origin private file system=] to disk, it is not intended that the contents are easily
-user accessible. Similarly there is no expectation that files or directories with names
-matching the names of children of the [=origin private file system=] exist.
-
-<xmp class=idl>
-[SecureContext]
-partial interface StorageManager {
-  Promise<FileSystemDirectoryHandle> getDirectory();
-};
-</xmp>
-
-Advisement: In Chrome this functionality was previously exposed as `FileSystemDirectoryHandle.getSystemDirectory({type: "sandbox"})`.
-This new method is available as of Chrome 85.
-
-<div class="note domintro">
-  : |directoryHandle| = await navigator . storage . {{StorageManager/getDirectory()}}
-  :: Returns the root directory of the origin private file system.
-</div>
-
-<div algorithm>
-The <dfn method for=StorageManager>getDirectory()</dfn> method, when
-invoked, must run these steps:
-
-1. Let |environment| be the [=current settings object=].
-
-1. Let |map| be the result of running [=obtain a local storage bottle map=]
-   with |environment| and `"fileSystem"`. If this returns failure,
-   return [=a promise rejected with=] a {{SecurityError}}.
-
-1. If |map|["root"] does not [=map/exist=]:
-  1. Let |dir| be a new [=directory entry=].
-  1. Set |dir|'s [=entry/name=] to `""`.
-  1. Set |dir|'s [=directory entry/children=] to an empty [=/set=].
-  1. Set |map|["root"] to |dir|.
-
-1. Return [=a promise resolved with=] a new {{FileSystemDirectoryHandle}},
-   whose associated [=FileSystemHandle/entry=] is |map|["root"].
-
-</div>
-
-Note: In Chrome the directory entry returned by the above algorithm refers to the same storage as the
-<a href="https://dev.w3.org/2009/dap/file-system/file-dir-sys.html#dfn-temporary">temporary
-file system</a> as used to be defined in [[file-system-api|File API: Directories and System]].
-
 # Accessibility Considerations # {#accessibility-considerations}
 
 *This section is non-normative.*
@@ -1985,8 +1057,8 @@ hand files that are already executable likely remain that way, even after the fi
 through this API). Furthermore user agents are encouraged to apply things like Mark-of-the-Web to
 files created or modified by this API.
 
-Finally, user agents are encouraged to verify the contents of files modified by this API via <dfn>malware
-scans and safe browsing checks</dfn>, unless some kind of external strong trust relation already exists.
+Finally, user agents are encouraged to verify the contents of files modified by this API via malware
+scans and safe browsing checks, unless some kind of external strong trust relation already exists.
 This of course has effects on the performance characteristics of this API.
 
 ## Ransomware attacks ## {#security-ransomware}

From d51bde19b88edeb6ca298ce13eca4dcf27a0d2d4 Mon Sep 17 00:00:00 2001
From: Austin Sullivan <asully@chromium.org>
Date: Sat, 19 Nov 2022 00:17:40 +0000
Subject: [PATCH 2/2] use newly exported terms

---
 index.bs | 31 +++++++++----------------------
 1 file changed, 9 insertions(+), 22 deletions(-)

diff --git a/index.bs b/index.bs
index 6e5b507..6d7372c 100644
--- a/index.bs
+++ b/index.bs
@@ -25,12 +25,6 @@ urlPrefix: https://tc39.github.io/ecma262/; spec: ECMA-262
   type: dfn; text: realm; url: realm
 urlPrefix: https://storage.spec.whatwg.org/; spec: storage
   type: dfn; text: storage; url: site-storage
-urlPrefix: https://fs.spec.whatwg.org/; spec: fs
-  type: dfn; text: binary data; url: file-entry-binary-data
-  type: dfn; text: directory entry; url: directory
-  type: dfn; text: entry; url: entry
-  type: dfn; text: file entry; url: file
-  type: dfn; text: origin private file system; url: origin-private-file-system
 </pre>
 
 <style>
@@ -69,16 +63,6 @@ files and directories they've been given access to, allowing the web apps to
 later regain access to the same content without requiring the user to select the
 same file again.
 
-This API extends the API in [[FS]], which specifies an [=origin private file system=]
-which websites can get access to without having to first prompt the user for access.
-This enables use cases where a website wants to save data to disk before a user has
-picked a location to save to, without forcing the website to use a completely
-different storage mechanism with a different API for such files. It also makes it
-easier to write automated tests for code using this API. The entry point for this
-is the {{StorageManager/getDirectory()|navigator.storage.getDirectory()}} method.
-This is similar to the temporary file system as defined in earlier drafts of
-[[file-system-api|File API: Directories and System]].
-
 This API is similar to <a href="https://html.spec.whatwg.org/multipage/input.html#file-upload-state-(type=file)">`<input type=file>`</a>
 and <a href="https://wicg.github.io/entries-api/#html-forms">`<input type=file webkitdirectory>`</a>
 [[entries-api]]
@@ -86,6 +70,9 @@ in that user interaction happens through file and directory picker dialogs.
 Unlike those APIs, this API is currently purely a javascript API, and
 does not integrate with forms and/or input elements.
 
+This API extends the API in [[FS]], which specifies an [=origin private file system=]
+which websites can get access to without having to first prompt the user for access.
+
 # Files and Directories # {#files-and-directories}
 
 ## Concepts ## {#concepts}
@@ -123,11 +110,11 @@ permission-related algorithms and types are defined as follows:
   run these steps:
 
   1. Let |entry| be |desc|.{{FileSystemPermissionDescriptor/handle}}'s [=FileSystemHandle/entry=].
-  1. If |entry| represents an [=/entry=] in an [=origin private file system=],
+  1. If |entry| represents a [=/file system entry=] in an [=origin private file system=],
     this descriptor's [=permission state=] must always be {{PermissionState/"granted"}}.
-  1. Otherwise, if |entry|'s [=entry/parent=] is not null, this descriptor's [=permission state=] must be
+  1. Otherwise, if |entry|'s [=file system entry/parent=] is not null, this descriptor's [=permission state=] must be
     equal to the [=permission state=] for a descriptor with the same {{FileSystemPermissionDescriptor/mode}},
-    and a {{FileSystemPermissionDescriptor/handle}} representing |entry|'s [=entry/parent=].
+    and a {{FileSystemPermissionDescriptor/handle}} representing |entry|'s [=file system entry/parent=].
   1. Otherwise, if |desc|.{{FileSystemPermissionDescriptor/mode}} is {{"readwrite"}}:
     1. Let |read state| be the [=permission state=] for a descriptor
       with the same {{FileSystemPermissionDescriptor/handle}},
@@ -607,7 +594,7 @@ run the following steps:
 
 1. If |startIn| is a {{FileSystemHandle}}:
   1. Let |entry| be |startIn|'s [=FileSystemHandle/entry=].
-  1. If |entry| does not represent an [=/entry=] in an [=origin private file system=]:
+  1. If |entry| does not represent a [=/file system entry=] in an [=origin private file system=]:
     1. If |entry| is a [=file entry=], and a path on the local file system
        corresponding to the parent directory of |entry| can be determined,
        then return that path.
@@ -634,7 +621,7 @@ run the following steps:
 
 <div algorithm>
 To <dfn>remember a picked directory</dfn>, given an optional [=string=] |id|,
-an [=/entry=] |entry|, and an [=environment settings object=] |environment|,
+a [=/file system entry=] |entry|, and an [=environment settings object=] |environment|,
 run the following steps:
 
 1. Let |origin| be |environment|'s [=environment settings object/origin=].
@@ -913,7 +900,7 @@ The <dfn method for=DataTransferItem>getAsFileSystemHandle()</dfn> method steps
 
 1. Run the following steps [=in parallel=]:
 
-  1. Let |entry| be the [=/entry=] representing the dragged file or directory.
+  1. Let |entry| be the [=/file system entry=] representing the dragged file or directory.
 
   1. If |entry| is a [=file entry=]: