fix: unblock Deno.realPathSync (#493)

Author: nyannyacha

crates/base/src/runtime/mod.rs

@@ -639,7 +639,10 @@ where
       AnyError,
     > {
       let tmp_fs = TmpFs::try_from(maybe_tmp_fs_config.unwrap_or_default())?;
-      let fs = PrefixFs::new("/tmp", tmp_fs, Some(base_fs)).tmp_dir("/tmp");
+      let tmp_fs_actual_path = tmp_fs.actual_path().to_path_buf();
+      let fs = PrefixFs::new("/tmp", tmp_fs.clone(), Some(base_fs))
+        .tmp_dir("/tmp")
+        .add_fs(tmp_fs_actual_path, tmp_fs);
 
       Ok(
         if let Some(s3_fs) = maybe_s3_fs_config.map(S3Fs::new).transpose()? {

crates/base/test_cases/use-tmp-fs-3/index.ts

@@ -0,0 +1,15 @@
+const meowFile = await Deno.create('/tmp/meow');
+const meow = new TextEncoder().encode('meowmeow');
+await meowFile.write(meow);
+
+const meowRealPath = Deno.realPathSync('/tmp/meow');
+const meowFileContent = await Deno.readTextFile(meowRealPath);
+const isValid = meowFileContent == 'meowmeow';
+
+export default {
+    fetch() {
+        return new Response(null, {
+            status: isValid ? 200 : 500,
+        });
+    },
+};

crates/base/test_cases/user-worker-san-check/.blocklisted

@@ -31,7 +31,6 @@ openSync
 readDirSync
 readLink
 readLinkSync
-realPathSync
 removeSync
 rename
 renameSync

crates/base/tests/integration_tests.rs

@@ -2766,6 +2766,23 @@ async fn test_tmp_fs_usage() {
       TerminationToken::new()
     );
   }
+
+  {
+    integration_test!(
+      "./test_cases/main",
+      NON_SECURE_PORT,
+      "use-tmp-fs-3",
+      None,
+      None,
+      None,
+      None,
+      (|resp| async {
+        let resp = resp.unwrap();
+        assert_eq!(resp.status().as_u16(), 200);
+      }),
+      TerminationToken::new()
+    );
+  }
 }
 
 #[tokio::test]

crates/fs/impl/tmp_fs.rs

@@ -238,6 +238,12 @@ pub struct TmpFs {
   quota: Arc<Quota>,
 }
 
+impl TmpFs {
+  pub fn actual_path(&self) -> &Path {
+    self.root.path()
+  }
+}
+
 #[async_trait::async_trait(?Send)]
 impl deno_fs::FileSystem for TmpFs {
   fn cwd(&self) -> FsResult<PathBuf> {

ext/runtime/js/bootstrap.js

@@ -658,6 +658,7 @@ globalThis.bootstrapSBEdge = (opts, ctx) => {
       "open": true,
       "stat": true,
       "realPath": true,
+      "realPathSync": true,
       "create": true,
       "remove": true,
       "writeFile": true,