`resolveCommand` does not always resolve correctly (error in `deno_which`) about dax

[dsherret]

Do you see the directory in Deno.env.get("PATH")? What’s the extension of winget? Do you see that extension in Deno.env.get("PATHEXT")?

[xe54ck]

The directory does appear. The extension is exe.

PS C:\> cmd /c where winget
C:\Users\user\AppData\Local\Microsoft\WindowsApps\winget.exe

PS C:\> which winget
/c/Users/user/AppData/Local/Microsoft/WindowsApps/winget

C:\Users\user\AppData\Local\Microsoft\WindowsApps is on the path.

After inspecting the WindowsApps directory, it appears winget.exe is a symlink into another directory. This seems to be the common for applications installed by Windows Apps (winget is installed this way).

MINGW64 ~/AppData/Local/Microsoft/WindowsApps
$ ls -al
total 24
...
lrwxrwxrwx 1 user 197609 101 Mar 28 15:55 winget.exe -> '/c/Program Files/WindowsApps/Microsoft.DesktopAppInstaller_1.19.10173.0_x64__8wekyb3d8bbwe/winget.exe'*
lrwxrwxrwx 1 user 197609  93 Feb 15 10:37 wt.exe -> '/c/Program Files/WindowsApps/Microsoft.WindowsTerminal_1.16.10262.0_x64__8wekyb3d8bbwe/wt.exe'*
...

If I add the symlinked path directly to %PATH%, it does work. The issue is maybe the symlink?

[dsherret]

Thanks for investigating! Yeah it appears deno_which needs to handle symlinks.

[xe54ck]

Looks like updating deno_which's fileExists and fileExistsSync functions to use Deno.lstat resolves the issue.

Updated deno_which mod.ts:

  async fileExists(path: string): Promise<boolean> {
    try {
      const result = await Deno.lstat(path);
      return result.isFile;
    } catch (err) {
      if (err instanceof Deno.errors.PermissionDenied) {
        throw err;
      }
      return false;
    }
  }

  fileExistsSync(path: string): boolean {
    try {
      const result = Deno.lstatSync(path);
      return result.isFile;
    } catch (err) {
      if (err instanceof Deno.errors.PermissionDenied) {
        throw err;
      }
      return false;
    }
  }

The Deno docs state that Deno.stat Will always follow symlinks but that does not appear to be the case. For example, this simple code errors:

try {
   const stat = await Deno.stat(`C:/Users/user/AppData/Local/Microsoft/WindowsApps/winget.EXE`)
   console.log(stat)
} catch (e) {
   console.log(e)
}

Error: The file cannot be accessed by the system. (os error 1920): stat 'C:/Users/user/AppData/Local/Microsoft/WindowsApps/winget.EXE'
    at async Object.stat (ext:deno_fs/30_fs.js:323:15)
    at async file:///C:/Development/deno_which/test.ts:4:14

Is this a bug in Deno.stat or weird issue with Windows symlinks?

[dsherret]

I investigated and opened denoland/deno#18598

This is not a deno_which issue.