Initial commit

venv/lib/python3.10/site-packages/matplotlib/tests/test_backend_registry.py

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+from collections.abc import Sequence
+from typing import Any
+
+import pytest
+
+import matplotlib as mpl
+from matplotlib.backends import BackendFilter, backend_registry
+
+
+@pytest.fixture
+def clear_backend_registry():
+    # Fixture that clears the singleton backend_registry before and after use
+    # so that the test state remains isolated.
+    backend_registry._clear()
+    yield
+    backend_registry._clear()
+
+
+def has_duplicates(seq: Sequence[Any]) -> bool:
+    return len(seq) > len(set(seq))
+
+
+@pytest.mark.parametrize(
+    'framework,expected',
+    [
+        ('qt', 'qtagg'),
+        ('gtk3', 'gtk3agg'),
+        ('gtk4', 'gtk4agg'),
+        ('wx', 'wxagg'),
+        ('tk', 'tkagg'),
+        ('macosx', 'macosx'),
+        ('headless', 'agg'),
+        ('does not exist', None),
+    ]
+)
+def test_backend_for_gui_framework(framework, expected):
+    assert backend_registry.backend_for_gui_framework(framework) == expected
+
+
+def test_list_builtin():
+    backends = backend_registry.list_builtin()
+    assert not has_duplicates(backends)
+    # Compare using sets as order is not important
+    assert {*backends} == {
+        'gtk3agg', 'gtk3cairo', 'gtk4agg', 'gtk4cairo', 'macosx', 'nbagg', 'notebook',
+        'qtagg', 'qtcairo', 'qt5agg', 'qt5cairo', 'tkagg',
+        'tkcairo', 'webagg', 'wx', 'wxagg', 'wxcairo', 'agg', 'cairo', 'pdf', 'pgf',
+        'ps', 'svg', 'template',
+    }
+
+
+@pytest.mark.parametrize(
+    'filter,expected',
+    [
+        (BackendFilter.INTERACTIVE,
+         ['gtk3agg', 'gtk3cairo', 'gtk4agg', 'gtk4cairo', 'macosx', 'nbagg', 'notebook',
+          'qtagg', 'qtcairo', 'qt5agg', 'qt5cairo', 'tkagg',
+          'tkcairo', 'webagg', 'wx', 'wxagg', 'wxcairo']),
+        (BackendFilter.NON_INTERACTIVE,
+         ['agg', 'cairo', 'pdf', 'pgf', 'ps', 'svg', 'template']),
+    ]
+)
+def test_list_builtin_with_filter(filter, expected):
+    backends = backend_registry.list_builtin(filter)
+    assert not has_duplicates(backends)
+    # Compare using sets as order is not important
+    assert {*backends} == {*expected}
+
+
+def test_list_gui_frameworks():
+    frameworks = backend_registry.list_gui_frameworks()
+    assert not has_duplicates(frameworks)
+    # Compare using sets as order is not important
+    assert {*frameworks} == {
+        "gtk3", "gtk4", "macosx", "qt", "qt5", "qt6", "tk", "wx",
+    }
+
+
+@pytest.mark.parametrize("backend, is_valid", [
+    ("agg", True),
+    ("QtAgg", True),
+    ("module://anything", True),
+    ("made-up-name", False),
+])
+def test_is_valid_backend(backend, is_valid):
+    assert backend_registry.is_valid_backend(backend) == is_valid
+
+
+@pytest.mark.parametrize("backend, normalized", [
+    ("agg", "matplotlib.backends.backend_agg"),
+    ("QtAgg", "matplotlib.backends.backend_qtagg"),
+    ("module://Anything", "Anything"),
+])
+def test_backend_normalization(backend, normalized):
+    assert backend_registry._backend_module_name(backend) == normalized
+
+
+def test_deprecated_rcsetup_attributes():
+    match = "was deprecated in Matplotlib 3.9"
+    with pytest.warns(mpl.MatplotlibDeprecationWarning, match=match):
+        mpl.rcsetup.interactive_bk
+    with pytest.warns(mpl.MatplotlibDeprecationWarning, match=match):
+        mpl.rcsetup.non_interactive_bk
+    with pytest.warns(mpl.MatplotlibDeprecationWarning, match=match):
+        mpl.rcsetup.all_backends
+
+
+def test_entry_points_inline():
+    pytest.importorskip('matplotlib_inline')
+    backends = backend_registry.list_all()
+    assert 'inline' in backends
+
+
+def test_entry_points_ipympl():
+    pytest.importorskip('ipympl')
+    backends = backend_registry.list_all()
+    assert 'ipympl' in backends
+    assert 'widget' in backends
+
+
+def test_entry_point_name_shadows_builtin(clear_backend_registry):
+    with pytest.raises(RuntimeError):
+        backend_registry._validate_and_store_entry_points(
+            [('qtagg', 'module1')])
+
+
+def test_entry_point_name_duplicate(clear_backend_registry):
+    with pytest.raises(RuntimeError):
+        backend_registry._validate_and_store_entry_points(
+            [('some_name', 'module1'), ('some_name', 'module2')])
+
+
+def test_entry_point_identical(clear_backend_registry):
+    # Issue https://github.com/matplotlib/matplotlib/issues/28367
+    # Multiple entry points with the same name and value (value is the module)
+    # are acceptable.
+    n = len(backend_registry._name_to_module)
+    backend_registry._validate_and_store_entry_points(
+        [('some_name', 'some.module'), ('some_name', 'some.module')])
+    assert len(backend_registry._name_to_module) == n+1
+    assert backend_registry._name_to_module['some_name'] == 'module://some.module'
+
+
+def test_entry_point_name_is_module(clear_backend_registry):
+    with pytest.raises(RuntimeError):
+        backend_registry._validate_and_store_entry_points(
+            [('module://backend.something', 'module1')])
+
+
+@pytest.mark.parametrize('backend', [
+    'agg',
+    'module://matplotlib.backends.backend_agg',
+])
+def test_load_entry_points_only_if_needed(clear_backend_registry, backend):
+    assert not backend_registry._loaded_entry_points
+    check = backend_registry.resolve_backend(backend)
+    assert check == (backend, None)
+    assert not backend_registry._loaded_entry_points
+    backend_registry.list_all()  # Force load of entry points
+    assert backend_registry._loaded_entry_points
+
+
+@pytest.mark.parametrize(
+    'gui_or_backend, expected_backend, expected_gui',
+    [
+        ('agg', 'agg', None),
+        ('qt', 'qtagg', 'qt'),
+        ('TkCairo', 'tkcairo', 'tk'),
+    ]
+)
+def test_resolve_gui_or_backend(gui_or_backend, expected_backend, expected_gui):
+    backend, gui = backend_registry.resolve_gui_or_backend(gui_or_backend)
+    assert backend == expected_backend
+    assert gui == expected_gui
+
+
+def test_resolve_gui_or_backend_invalid():
+    match = "is not a recognised GUI loop or backend name"
+    with pytest.raises(RuntimeError, match=match):
+        backend_registry.resolve_gui_or_backend('no-such-name')