fix: only warn interactively when running as root

Author: gshmu

invoke/program.py

@@ -21,7 +21,7 @@
 from .exceptions import CollectionNotFound, Exit, ParseError, UnexpectedExit
 from .parser import Argument, Parser, ParserContext
 from .terminals import pty_size
-from .util import debug, enable_logging, helpline
+from .util import debug, enable_logging, helpline, isatty
 
 if TYPE_CHECKING:
     from .loader import Loader
@@ -430,7 +430,7 @@ def warn_if_running_as_root(self, is_testing: bool = False) -> None:
         """
         Emit a warning when Invoke is executed as the root user.
         """
-        if is_testing or not self.running_as_root():
+        if is_testing or not isatty(sys.stderr) or not self.running_as_root():
             return
         print(self.root_warning, file=sys.stderr)
 

tests/program.py

@@ -110,16 +110,26 @@ class root_warning:
             def prints_warning_to_tty_stderr(self):
                 program = Program()
                 with patch.object(program, "running_as_root", return_value=True):
+                    sys.stderr.isatty = Mock(return_value=True)
                     program.warn_if_running_as_root(is_testing=False)
                 assert (
                     sys.stderr.getvalue()
                     == "WARNING: Running Invoke as root may create root-owned files and cause later I/O or permission errors. Re-run as a non-root user.\n"
                 )
 
+            @trap
+            def does_not_warn_when_stderr_is_not_a_tty(self):
+                program = Program()
+                with patch.object(program, "running_as_root", return_value=True):
+                    sys.stderr.isatty = Mock(return_value=False)
+                    program.warn_if_running_as_root(is_testing=False)
+                assert sys.stderr.getvalue() == ""
+
             @trap
             def skips_warning_for_exit_false(self):
                 program = Program()
                 with patch.object(program, "running_as_root", return_value=True):
+                    sys.stderr.isatty = Mock(return_value=True)
                     program.warn_if_running_as_root(is_testing=True)
                 assert sys.stderr.getvalue() == ""