Make a stream readable.

doc/source/changelog.rst

@@ -1,6 +1,13 @@
 MontePy Changelog
 =================
 
+#Next Version#
+--------------
+
+**Bug Fixes**
+
+* Fixed bug where file streams couldn't actually be read (:pull:`553`).
+
 0.4.1
 --------------
 

montepy/input_parser/input_file.py

@@ -31,6 +31,7 @@ def __init__(self, path, parent_file=None, overwrite=False):
         self._overwrite = overwrite
         self._mode = None
         self._fh = None
+        self._is_stream = False
 
     @classmethod
     def from_open_stream(cls, fh):
@@ -43,6 +44,7 @@ def from_open_stream(cls, fh):
         name = getattr(fh, "name", fh.__class__.__name__)
         inpfile = cls(path=name)
         inpfile._fh = fh
+        inpfile._is_stream = True
         return inpfile
 
     @make_prop_pointer("_path")
@@ -56,7 +58,11 @@ def path(self):
 
     @property
     def name(self):
-        return self.path
+        return self._path
+
+    @property
+    def is_stream(self):
+        return self._is_stream
 
     @make_prop_pointer("_parent_file")
     def parent_file(self):

montepy/input_parser/input_syntax_reader.py

@@ -38,7 +38,11 @@ def read_input_syntax(input_file, mcnp_version=DEFAULT_VERSION, replace=True):
     """
     global reading_queue
     reading_queue = deque()
-    with input_file.open("r", replace=replace) as fh:
+    if input_file.is_stream:
+        context = input_file
+    else:
+        context = input_file.open("r", replace=replace)
+    with context as fh:
         yield from read_front_matters(fh, mcnp_version)
         yield from read_data(fh, mcnp_version)
 

tests/test_integration.py

@@ -1106,10 +1106,12 @@ def test_read_write_cycle(file):
     problem = montepy.read_input(file)
     SKIPPERS = _SKIP_LINES.get(str(file), {})
     fh = io.StringIO()
+    # make string unclosable to keep open after reading.
+    fh.close = lambda: None
     problem.write_problem(fh)
     fh.seek(0)
     # test valid syntax
-    new_problem = montepy.MCNP_Problem("foo")
+    new_problem = montepy.read_input(fh)
     # verify lines are similar
     fh.seek(0)
     lines = [line.rstrip() for line in fh]