FUTURE(ext/fs): stabilize file system APIs (#23968)

Closes https://github.com/denoland/deno/issues/23906

---------

Co-authored-by: Asher Gomez <ashersaupingomez@gmail.com>

cli/args/mod.rs

@@ -1754,6 +1754,13 @@ impl CliOptions {
       .unwrap_or_default();
 
     from_config_file.extend_from_slice(&self.flags.unstable_config.features);
+
+    if *DENO_FUTURE {
+      from_config_file.extend_from_slice(&[
+        deno_runtime::deno_fs::UNSTABLE_FEATURE_NAME.to_string(),
+      ]);
+    }
+
     from_config_file
   }
 

tests/specs/future/unstable_flags/__test__.jsonc

@@ -0,0 +1,20 @@
+{
+  "steps": [
+    {
+      // Notice `--unstable-*` flags are not needed anymore
+      "args": "run -A main.js",
+      "output": "main.out",
+      "envs": {
+        "DENO_FUTURE": "1"
+      }
+    },
+    {
+      // Notice `--unstable-*` flags are not needed anymore
+      "args": "run -A worker.js",
+      "output": "main.out",
+      "envs": {
+        "DENO_FUTURE": "1"
+      }
+    }
+  ]
+}

tests/specs/future/unstable_flags/main.js

@@ -0,0 +1,4 @@
+console.log(
+  // Undefined without `--unstable-fs`
+  Deno.build.os === "windows" ? true : typeof Deno.umask === "function",
+);

tests/specs/future/unstable_flags/main.out

@@ -0,0 +1 @@
+true

tests/specs/future/unstable_flags/worker.js

@@ -0,0 +1,5 @@
+import { delay } from "../../../util/std/async/delay.ts";
+
+const worker = new Worker(import.meta.resolve("./main.js"), { type: "module" });
+await delay(1_000);
+worker.terminate();