diff --git a/Lib/test/test_cgi.py b/Lib/test/test_cgi.py
index 8ea2484ae..205697cb2 100644
--- a/Lib/test/test_cgi.py
+++ b/Lib/test/test_cgi.py
@@ -203,8 +203,6 @@ Content-Length: 3
             self.addCleanup(cgi.closelog)
             cgi.log("Testing log 4")
 
-    # TODO RUSTPYTHON
-    @unittest.expectedFailure
     def test_fieldstorage_readline(self):
         # FieldStorage uses readline, which has the capacity to read all
         # contents of the input file into memory; we use readline's size argument
@@ -294,8 +292,6 @@ Content-Length: 3
                     got = getattr(fs.list[x], k)
                     self.assertEqual(got, exp)
 
-    # TODO RUSTPYTHON
-    @unittest.expectedFailure
     def test_fieldstorage_multipart_maxline(self):
         # Issue #18167
         maxline = 1 << 16
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index ba514814f..6bb61b6da 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -732,8 +732,6 @@ class IOTest(unittest.TestCase):
         self.assertRaises(ValueError, self.open, support.TESTFN, 'w',
                           closefd=False)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_read_closed(self):
         with self.open(support.TESTFN, "w") as f:
             f.write("egg\n")
@@ -893,8 +891,6 @@ class IOTest(unittest.TestCase):
             open('non-existent', 'r', opener=badopener)
         self.assertEqual(str(cm.exception), 'opener returned -2')
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_fileio_closefd(self):
         # Issue #4841
         with self.open(__file__, 'rb') as f1, \
diff --git a/Lib/test/test_iter.py b/Lib/test/test_iter.py
index 368694c6f..51e52bc4f 100644
--- a/Lib/test/test_iter.py
+++ b/Lib/test/test_iter.py
@@ -768,9 +768,6 @@ class TestCase(unittest.TestCase):
             self.assertEqual(indexOf(iclass, i), i)
         self.assertRaises(ValueError, indexOf, iclass, -1)
 
-    # Test iterators with file.writelines().
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_writelines(self):
         f = open(TESTFN, "w")
 
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 12b439746..43d93f58b 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -190,8 +190,6 @@ class FileTests(unittest.TestCase):
         new = sys.getrefcount(path)
         self.assertEqual(old, new)
 
-    # TODO: RUSTPYTHON (OSError: Bad file descriptor (os error 9))
-    @unittest.expectedFailure
     def test_read(self):
         with open(support.TESTFN, "w+b") as fobj:
             fobj.write(b"spam")
diff --git a/Lib/test/test_raise.py b/Lib/test/test_raise.py
index 062b8fcc1..8a22369b7 100644
--- a/Lib/test/test_raise.py
+++ b/Lib/test/test_raise.py
@@ -376,8 +376,6 @@ class TestContext(unittest.TestCase):
         else:
             self.fail("No exception raised")
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_raise_finally(self):
         try:
             try:
@@ -389,8 +387,6 @@ class TestContext(unittest.TestCase):
         else:
             self.fail("No exception raised")
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_context_manager(self):
         class ContextManager:
             def __enter__(self):
diff --git a/src/main.rs b/src/main.rs
index 28709e017..51649c270 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -12,7 +12,7 @@ use rustpython_vm::{
     match_class,
     pyobject::{BorrowValue, ItemProtocol, PyResult, TypeProtocol},
     scope::Scope,
-    util, InitParameter, Interpreter, PySettings, VirtualMachine,
+    sysmodule, util, InitParameter, Interpreter, PySettings, VirtualMachine,
 };
 
 use std::convert::TryInto;
@@ -56,6 +56,8 @@ fn main() {
     let exitcode = interp.enter(move |vm| {
         let res = run_rustpython(vm, &matches);
 
+        flush_std(vm);
+
         #[cfg(feature = "flame-it")]
         {
             main_guard.end();
@@ -103,12 +105,23 @@ fn main() {
 
         let _ = vm.run_atexit_funcs();
 
+        flush_std(vm);
+
         exitcode
     });
 
     process::exit(exitcode);
 }
 
+fn flush_std(vm: &VirtualMachine) {
+    if let Ok(stdout) = sysmodule::get_stdout(vm) {
+        let _ = vm.call_method(&stdout, "flush", ());
+    }
+    if let Ok(stderr) = sysmodule::get_stderr(vm) {
+        let _ = vm.call_method(&stderr, "flush", ());
+    }
+}
+
 fn parse_arguments<'a>(app: App<'a, '_>) -> ArgMatches<'a> {
     let app = app
         .setting(AppSettings::TrailingVarArg)
diff --git a/vm/src/lib.rs b/vm/src/lib.rs
index ad94fff03..082f4b61b 100644
--- a/vm/src/lib.rs
+++ b/vm/src/lib.rs
@@ -69,7 +69,7 @@ mod sequence;
 mod sliceable;
 pub mod slots;
 pub mod stdlib;
-mod sysmodule;
+pub mod sysmodule;
 pub mod types;
 pub mod util;
 mod version;
diff --git a/vm/src/stdlib/io.rs b/vm/src/stdlib/io.rs
index 1c75a751f..aa3127eca 100644
--- a/vm/src/stdlib/io.rs
+++ b/vm/src/stdlib/io.rs
@@ -887,7 +887,11 @@ mod _io {
                 match res {
                     Some(n) => {
                         written += n;
-                        remaining -= n;
+                        if let Some(r) = remaining.checked_sub(n) {
+                            remaining = r
+                        } else {
+                            break;
+                        }
                         vm.check_signals()?;
                     }
                     None => {
@@ -1923,6 +1927,14 @@ mod _io {
             let buffer = self.lock(vm)?.buffer.clone();
             vm.get_attribute(buffer, "name")
         }
+        #[pyproperty]
+        fn encoding(&self, vm: &VirtualMachine) -> PyResult<PyStrRef> {
+            Ok(self.lock(vm)?.encoding.clone())
+        }
+        #[pyproperty]
+        fn errors(&self, vm: &VirtualMachine) -> PyResult<PyStrRef> {
+            Ok(self.lock(vm)?.errors.clone())
+        }
 
         #[pymethod]
         fn fileno(&self, vm: &VirtualMachine) -> PyResult {
diff --git a/vm/src/stdlib/os.rs b/vm/src/stdlib/os.rs
index b2e9bd7a7..11481bc65 100644
--- a/vm/src/stdlib/os.rs
+++ b/vm/src/stdlib/os.rs
@@ -114,6 +114,12 @@ fn fs_metadata<P: AsRef<Path>>(path: P, follow_symlink: bool) -> io::Result<fs::
     }
 }
 
+impl AsRef<Path> for PyPathLike {
+    fn as_ref(&self) -> &Path {
+        &self.path
+    }
+}
+
 impl TryFromObject for PyPathLike {
     fn try_from_object(vm: &VirtualMachine, obj: PyObjectRef) -> PyResult<Self> {
         let match1 = |obj: &PyObjectRef| {
@@ -924,6 +930,23 @@ mod _os {
         Ok(())
     }
 
+    #[pyfunction]
+    fn truncate(path: PyObjectRef, length: Offset, vm: &VirtualMachine) -> PyResult<()> {
+        if let Ok(fd) = i64::try_from_object(vm, path.clone()) {
+            return ftruncate(fd, length, vm);
+        }
+        let path = PyPathLike::try_from_object(vm, path)?;
+        // TODO: just call libc::truncate() on POSIX
+        let f = OpenOptions::new()
+            .write(true)
+            .open(&path)
+            .map_err(|e| e.into_pyexception(vm))?;
+        f.set_len(length as u64)
+            .map_err(|e| e.into_pyexception(vm))?;
+        drop(f);
+        Ok(())
+    }
+
     #[pyattr]
     #[pyclass(module = "os", name = "terminal_size")]
     #[derive(PyStructSequence)]
diff --git a/vm/src/sysmodule.rs b/vm/src/sysmodule.rs
index 654e7fef8..50941462d 100644
--- a/vm/src/sysmodule.rs
+++ b/vm/src/sysmodule.rs
@@ -403,7 +403,7 @@ const ABIFLAGS: &str = "";
 // https://github.com/python/cpython/blob/3.8/configure.ac#L725
 const MULTIARCH: &str = env!("RUSTPYTHON_TARGET_TRIPLE");
 
-pub fn sysconfigdata_name() -> String {
+pub(crate) fn sysconfigdata_name() -> String {
     format!("_sysconfigdata_{}_{}_{}", ABIFLAGS, PLATFORM, MULTIARCH)
 }
 
@@ -484,7 +484,7 @@ impl PyIntInfo {
     };
 }
 
-pub fn make_module(vm: &VirtualMachine, module: PyObjectRef, builtins: PyObjectRef) {
+pub(crate) fn make_module(vm: &VirtualMachine, module: PyObjectRef, builtins: PyObjectRef) {
     let ctx = &vm.ctx;
 
     let _flags_type = SysFlags::make_class(ctx);