Merge pull request #11 from ModelCloud/codex/check-logbar-api-terminal-state-requirement

Allow LogBar to run without a terminal

Author: Qubitium

logbar/terminal.py

@@ -1,6 +1,6 @@
 # adapted from github.com/onsim/shutils
 import os
-import sys
+import shutil
 
 
 def terminal_size(fallback=(80, 24)):
@@ -11,8 +11,7 @@ def terminal_size(fallback=(80, 24)):
     the value is a positive integer, it is used.
 
     When COLUMNS or LINES is not defined, which is the common case,
-    the terminal connected to sys.__stdout__ is queried
-    by invoking os.get_terminal_size.
+    shutil.get_terminal_size is used to determine the current terminal size.
 
     If the terminal size cannot be successfully queried, either because
     the system doesn't support querying, or because we are not
@@ -36,10 +35,11 @@ def terminal_size(fallback=(80, 24)):
     # only query if necessary
     if columns <= 0 or lines <= 0:
         try:
-            size = os.get_terminal_size(sys.__stdout__.fileno())
-        except (AttributeError, ValueError, OSError):
-            # stdout is None, closed, detached, or not a terminal, or
-            # os.get_terminal_size() is unsupported
+            size = shutil.get_terminal_size(fallback)
+        except (OSError, ValueError):
+            # shutil.get_terminal_size failed because the runtime does not have an
+            # attached terminal. Fall back to the provided default which mirrors
+            # the behaviour of shutil.get_terminal_size when a fallback is supplied.
             size = os.terminal_size(fallback)
         if columns <= 0:
             columns = size.columns or fallback[0]

tests/test_log.py

@@ -1,6 +1,8 @@
 import io
-import unittest
 from contextlib import redirect_stdout
+import unittest
+from unittest import mock
+
 
 from logbar import LogBar
 
@@ -29,6 +31,19 @@ def test_levels(self):
         log.error("hello error")
         log.critical("hello critical")
 
+    def test_log_without_terminal_state(self):
+        """LogBar should operate even when the runtime lacks a terminal."""
+
+        stdout = io.StringIO()
+
+        with mock.patch('sys.stdout', stdout), \
+             mock.patch('logbar.terminal.shutil.get_terminal_size', side_effect=OSError()), \
+             mock.patch.dict('logbar.terminal.os.environ', {}, clear=True):
+            log.info("logging without terminal")
+
+        # The log output should have been written to the patched stdout buffer.
+        self.assertIn("logging without terminal", stdout.getvalue())
+
     def test_percent_formatting(self):
         output = self.capture_log(log.info, "%d", 123)
         self.assertIn("123", output)

tests/test_progress.py

@@ -116,3 +116,16 @@ def test_draw_respects_terminal_width(self):
         rendered_line = output.lstrip('\r')
 
         self.assertEqual(len(rendered_line), columns)
+
+    def test_draw_without_terminal_state(self):
+        pb = log.pb(10).manual()
+        pb.current_iter_step = 5
+
+        with patch('logbar.terminal.shutil.get_terminal_size', side_effect=OSError()), \
+             patch.dict('logbar.terminal.os.environ', {}, clear=True):
+            buffer = StringIO()
+            with redirect_stdout(buffer):
+                pb.draw()
+
+        output = buffer.getvalue()
+        self.assertIn('[5/10]', output)