FUTURE(ext/fs): make `Deno.FsFile` constructor illegal (#23235)

I'm unsure whether we're planning to make the `Deno.FsFile` constructor
illegal or remove `FsFile` from the `Deno.*` namspace in Deno 2. Either
way, this PR works towards the former. I'll create a superceding PR if
the latter is planned instead.

Towards #23089

1 files changed, 6 insertions, 0 deletions

diff --git a/ext/fs/30_fs.js b/ext/fs/30_fs.js
index c2fb66528..b6cd2d1f1 100644
--- a/ext/fs/30_fs.js
+++ b/ext/fs/30_fs.js
@@ -90,6 +90,7 @@ const {
   SymbolAsyncIterator,
   SymbolIterator,
   SymbolFor,
+  TypeError,
   Uint32Array,
 } = primordials;
 
@@ -673,6 +674,11 @@ class FsFile {
         new Error().stack,
         "Use `Deno.open` or `Deno.openSync` instead.",
       );
+      if (internals.future) {
+        throw new TypeError(
+          "`Deno.FsFile` cannot be constructed, use `Deno.open()` or `Deno.openSync()` instead.",
+        );
+      }
     }
   }