fix(polyfill): correctly handle flag when its equal 0 (#20953)

Fixes https://github.com/denoland/deno/issues/20910

2 files changed, 25 insertions, 0 deletions

diff --git a/cli/tests/unit_node/_fs/_fs_open_test.ts b/cli/tests/unit_node/_fs/_fs_open_test.ts
index b64e6c4c5..d9f5e5796 100644
--- a/cli/tests/unit_node/_fs/_fs_open_test.ts
+++ b/cli/tests/unit_node/_fs/_fs_open_test.ts
@@ -397,4 +397,14 @@ Deno.test("[std/node/fs] open callback isn't called twice if error is thrown", a
       await Deno.remove(tempFile);
     },
   });
+
+  Deno.test({
+    name: "SYNC: open file with flag set to 0 (readonly)",
+    fn() {
+      const file = Deno.makeTempFileSync();
+      const fd = openSync(file, 0);
+      assert(Deno.resources()[fd]);
+      closeSync(fd);
+    },
+  });
 });
diff --git a/cli/tests/unit_node/_fs/_fs_read_test.ts b/cli/tests/unit_node/_fs/_fs_read_test.ts
index 66906ccbc..34b029d9f 100644
--- a/cli/tests/unit_node/_fs/_fs_read_test.ts
+++ b/cli/tests/unit_node/_fs/_fs_read_test.ts
@@ -306,3 +306,18 @@ Deno.test({
     await Deno.remove(file);
   },
 });
+
+Deno.test({
+  name: "SYNC: read with no offsetOropts argument",
+  fn() {
+    const moduleDir = path.dirname(path.fromFileUrl(import.meta.url));
+    const testData = path.resolve(moduleDir, "testdata", "hello.txt");
+    const buffer = Buffer.alloc(1024);
+    const fd = openSync(testData, "r");
+    const _bytesRead = readSync(
+      fd,
+      buffer,
+    );
+    closeSync(fd);
+  },
+});