fix(cli): restore progress bars on human format and check tty in auto mode (#4860)

src/huggingface_hub/cli/_output.py

@@ -27,7 +27,14 @@
 import click
 
 from huggingface_hub.errors import ConfirmationError
-from huggingface_hub.utils import ANSI, StatusLine, disable_progress_bars, is_agent, tabulate
+from huggingface_hub.utils import (
+    ANSI,
+    StatusLine,
+    disable_progress_bars,
+    enable_progress_bars,
+    is_agent,
+    tabulate,
+)
 
 
 class OutputFormat(str, Enum):
@@ -63,10 +70,13 @@ def __init__(self) -> None:
     def set_mode(self, mode: OutputFormat = OutputFormat.auto) -> None:
         """Override the output mode (called once at startup and again per '--format' flag)."""
         if mode == OutputFormat.auto:
-            mode = OutputFormat.agent if is_agent() else OutputFormat.human
+            is_interactive = bool(getattr(sys.stderr, "isatty", lambda: False)())
+            mode = OutputFormat.agent if (is_agent() and not is_interactive) else OutputFormat.human
         self.mode = mode
         if mode != OutputFormat.human:
             disable_progress_bars()
+        else:
+            enable_progress_bars()
 
     def set_no_truncate(self, no_truncate: bool) -> None:
         """Toggle off cell truncation for human table output."""

src/huggingface_hub/utils/_terminal.py

@@ -99,7 +99,7 @@ def yellow(cls, s: str) -> str:
 
     @classmethod
     def _format(cls, s: str, code: str) -> str:
-        if os.environ.get("NO_COLOR") or is_agent():
+        if os.environ.get("NO_COLOR") or (is_agent() and not bool(getattr(sys.stderr, "isatty", lambda: False)())):
             # See https://no-color.org/
             return s
         return f"{code}{s}{cls._reset}"

tests/test_cli_output.py

@@ -22,6 +22,7 @@
 
 from huggingface_hub.cli._output import Output, OutputFormat, _ascii_safe, _to_header
 from huggingface_hub.errors import ConfirmationError
+from huggingface_hub.utils import are_progress_bars_disabled, enable_progress_bars
 
 
 HUMAN = OutputFormat.human
@@ -86,6 +87,47 @@ def test_auto_resets_after_explicit():
     assert o.mode == HUMAN
 
 
+def test_set_mode_human_reenables_progress_bars():
+    try:
+        o = Output()
+        o.set_mode(OutputFormat.agent)
+        assert are_progress_bars_disabled()
+        o.set_mode(OutputFormat.human)
+        assert not are_progress_bars_disabled()
+    finally:
+        enable_progress_bars()
+
+
+def test_auto_resolves_to_human_in_interactive_terminal_even_if_agent(monkeypatch):
+    monkeypatch.setattr("huggingface_hub.cli._output.is_agent", lambda: True)
+    monkeypatch.setattr(sys.stderr, "isatty", lambda: True)
+    assert Output().mode == HUMAN
+
+
+def test_auto_resolves_to_agent_when_not_interactive(monkeypatch):
+    monkeypatch.setattr("huggingface_hub.cli._output.is_agent", lambda: True)
+    monkeypatch.setattr(sys.stderr, "isatty", lambda: False)
+    assert Output().mode == AGENT
+
+
+def test_explicit_agent_mode_forces_agent_even_if_interactive(monkeypatch):
+    monkeypatch.setattr(sys.stderr, "isatty", lambda: True)
+    o = Output()
+    o.set_mode(OutputFormat.agent)
+    assert o.mode == AGENT
+
+
+def test_explicit_agent_mode_disables_bars_even_in_interactive(monkeypatch):
+    monkeypatch.setattr(sys.stderr, "isatty", lambda: True)
+    try:
+        o = Output()
+        o.set_mode(OutputFormat.agent)
+        assert o.mode == AGENT
+        assert are_progress_bars_disabled()
+    finally:
+        enable_progress_bars()
+
+
 # =============================================================================
 # out.result()
 # =============================================================================

tests/test_utils_terminal.py

@@ -1,4 +1,5 @@
 import os
+import sys
 from unittest import mock
 
 import pytest
@@ -30,6 +31,20 @@ def test_ansi_no_color(self) -> None:
 
         assert ANSI.gray(ANSI.bold("this is bold and grey")) == "this is bold and grey"
 
+    @mock.patch.dict(os.environ, {}, clear=True)
+    def test_ansi_agent_interactive_preserves_color(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        """Test `ANSI` does not suppress color in interactive terminal even if is_agent() is True."""
+        monkeypatch.setattr("huggingface_hub.utils._terminal.is_agent", lambda: True)
+        monkeypatch.setattr(sys.stderr, "isatty", lambda: True)
+        assert ANSI.bold("this is bold") == "\x1b[1mthis is bold\x1b[0m"
+
+    @mock.patch.dict(os.environ, {}, clear=True)
+    def test_ansi_agent_non_interactive_suppresses_color(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        """Test `ANSI` suppresses color in non-interactive session when is_agent() is True."""
+        monkeypatch.setattr("huggingface_hub.utils._terminal.is_agent", lambda: True)
+        monkeypatch.setattr(sys.stderr, "isatty", lambda: False)
+        assert ANSI.bold("this is bold") == "this is bold"
+
     def test_tabulate_utility(self) -> None:
         """Test `tabulate` works as expected."""
         rows = [[1, 2, 3], ["a very long value", "foo", "bar"], ["", 123, 456]]