terminalwriter: bring back handling of printing characters not supported by stdout

Author: bluetech

src/_pytest/_io/terminalwriter.py

@@ -149,7 +149,18 @@ def write(self, msg: str, *, flush: bool = False, **markup: bool) -> None:
 
             msg = self.markup(msg, **markup)
 
-            self._file.write(msg)
+            try:
+                self._file.write(msg)
+            except UnicodeEncodeError:
+                # Some environments don't support printing general Unicode
+                # strings, due to misconfiguration or otherwise; in that case,
+                # print the string escaped to ASCII.
+                # When the Unicode situation improves we should consider
+                # letting the error propagate instead of masking it (see #7475
+                # for one brief attempt).
+                msg = msg.encode("unicode-escape").decode("ascii")
+                self._file.write(msg)
+
             if flush:
                 self.flush()
 

testing/io/test_terminalwriter.py

@@ -49,6 +49,15 @@ def isatty(self):
         assert not tw.hasmarkup
 
 
+def test_terminalwriter_not_unicode() -> None:
+    """If the file doesn't support Unicode, the string is unicode-escaped (#7475)."""
+    buffer = io.BytesIO()
+    file = io.TextIOWrapper(buffer, encoding="cp1252")
+    tw = terminalwriter.TerminalWriter(file)
+    tw.write("hello 🌀 wôrld אבג", flush=True)
+    assert buffer.getvalue() == br"hello \U0001f300 w\xf4rld \u05d0\u05d1\u05d2"
+
+
 win32 = int(sys.platform == "win32")