[meta] Use the vscode filesystem API for *all* filesystem operations.

[ericsnowcurrently]

With version , VS Code added a new filesystem API, to provide a consistent and reliable experience on different platforms and execution environments (including remote). The extension should use it as much as possible.

The API

vscode.workspace.fs.*
  copy(source: Uri, target: Uri, options?: {overwrite: boolean}): Thenable<void>
  createDirectory(uri: Uri): Thenable<void>
  delete(uri: Uri, options?: {recursive: boolean, useTrash: boolean}): Thenable<void>
  readDirectory(uri: Uri): Thenable<[string, FileType][]>
  readFile(uri: Uri): Thenable<Uint8Array>
  rename(source: Uri, target: Uri, options?: {overwrite: boolean}): Thenable<void>
  stat(uri: Uri): Thenable<FileStat>
  writeFile(uri: Uri, content: Uint8Array): Thenable<void>

vscode.FileStat
vscode.FileType

For reference:

• https://nodejs.org/api/fs.html
• https://github.com/jprichardson/node-fs-extra#methods

How to Switch?

PRs:

• Update the code base to use IFileSystem instead of fs and fs-extra. #7915 (for Use VS Code FS API #6911)
• Use new VS Code filesystem API. #8307 (for Use VS Code FS API #6911)

Tasks:

• identify all current filesystem usage (see [meta] Code health for filesystem interaction. #8801)
• consolidate all filesystem usage into IFileSystem (see [meta] Code health for filesystem interaction. #8801)
• ensure we keep using only our wrapper in the future (see [meta] Code health for filesystem interaction. #8801)
• improve testability (see [meta] Code health for filesystem interaction. #8801)
• use the vscode.workspace.fs API as a replacement:
  • node's "fs" module is completely subsumed by "fs-extra"
  • "fs-extra" module
    • (missing) chmod() -> ???
      • covered by Enable FileSystemProvider to stat a file as readonly vscode#73122 and FileSystemProvider: no way of handling permissions issues vscode#48659
    • (Use VS Code FS API #6911) readFile() -> readFile()
    • (Use VS Code FS API #6911) writeFile() -> writeFile()
    • (Use VS Code FS API #6911) unlink() -> delete()
    • (Use VS Code FS API #6911) stat() -> stat()
    • (missing) lstat() -> ???
      • covered by File Provider: support symbolic link operations vscode#71204
      • maybe use stat() instead?
    • (Use VS Code FS API #6911) mkdirp() -> createDirectory()
    • (Use VS Code FS API #6911) rmdir() -> delete()
    • (Use VS Code FS API #6911) readdir() -> `readDirectory()
    • (Use VS Code FS API #6911) remove() -> delete()
      • this is a recursive delete (i.e. rmtree())
    • (TODO) statSync() -> ???
      • per Support for sync functions in the vscode.workspace.fs API. vscode#84518, not going to happen
      • switch from sync to async?
    • (TODO) readFileSync() -> ???
      • per Support for sync functions in the vscode.workspace.fs API. vscode#84518, not going to happen
      • switch from sync to async?
    • (Use VS Code FS API #6911) createReadStream() - goes away once we use copy()
    • (Use VS Code FS API #6911) stop using createWriteStream() for copy()
    • (missing) createWriteStream() -> ???
      • requested: Add vscode.workspace.fs.createWriteStream(). vscode#84515
  • "tmp" module
    • (missing) file() -> ???
      • requested Add vscode.workspace.fs.mkdtemp(). vscode#84517
  • "glob" module
    • (TODO) glob() -> vscode.workspace.findFiles()
      • see Add more functionality to the "vscode.workspace.fs" API. vscode#84175
  • ...
• drop workarounds
  • (TODO) drop tree traversal code (per Add vscode.workspace.fs.mkdirp(). vscode#84516)
  • (blocked) FileStat.ctime == 0
    • reported: vscode.workspace.fs.stat(): wrong creation time. vscode#84525
    • drop: ...
  • (blocked) unexpected successes
    • reported: vscode.workspace.fs.remove() (and copy()) succeed unexpectedly. vscode#84177
    • drop: ...
  • (blocked) sockets as FileType.File
    • reported: vscode.workspace.fs.stat(): sockets identified as "regular" files. vscode#84524
    • drop: ...

[ericsnowcurrently]

FWIW, I'm not sure this is totally done (would have to check), but it's probably better closed for now. We can revive it or dupe it later if that turns out to matter.