add more unittests

Ultraplot · beckermr · Nov 20, 2025 · Nov 12, 2025 · Nov 12, 2025 · Nov 12, 2025
commit d5421032afb23c8ea6987bd25d9bc1e032e3fb3b
diff --git a/ultraplot/tests/test_integration.py b/ultraplot/tests/test_integration.py
@@ -2,10 +2,73 @@
 """
 Test xarray, pandas, pint, seaborn integration.
 """
-import numpy as np, pandas as pd, seaborn as sns
-import xarray as xr
-import ultraplot as uplt, pytest
+import numpy as np
+import pandas as pd
 import pint
+import pytest
+import seaborn as sns
+import xarray as xr
+
+import ultraplot as uplt
+
+
+def test_seaborn_helpers_filtered_from_legend():
+    """
+    Seaborn-generated helper artists (e.g., CI bands) must be synthetic-tagged and
+    filtered out of legends so that only hue categories appear.
+    """
+    fig, ax = uplt.subplots()
+
+    # Create simple dataset with two hue levels
+    df = pd.DataFrame(
+        {
+            "x": np.concatenate([np.arange(10)] * 2),
+            "y": np.concatenate([np.arange(10), np.arange(10) + 1]),
+            "hue": ["h1"] * 10 + ["h2"] * 10,
+        }
+    )
+
+    # Draw seaborn lineplot (which may create helper artists internally)
+    sns.lineplot(data=df, x="x", y="y", hue="hue", ax=ax)
+
+    # Explicitly create legend and verify labels
+    leg = ax.legend()
+    labels = {t.get_text() for t in leg.get_texts()}
+
+    # Only hue labels should be present
+    assert {"h1", "h2"}.issubset(labels)
+
+    # Spurious or synthetic labels must not appear
+    for bad in (
+        "y",
+        "ymin",
+        "ymax",
+        "_ultraplot_fill",
+        "_ultraplot_shade",
+        "_ultraplot_fade",
+    ):
+        assert bad not in labels
+
+
+def test_user_labeled_shading_appears_in_legend():
+    """
+    User-labeled shading (fill_between) must appear in legend even after seaborn plotting.
+    """
+    fig, ax = uplt.subplots()
+
+    # Seaborn plot first (to ensure seaborn context was present earlier)
+    df = pd.DataFrame({"x": np.arange(10), "y": np.arange(10)})
+    sns.lineplot(data=df, x="x", y="y", ax=ax, label="line")
+
+    # Add explicit user-labeled shading on the same axes
+    x = np.arange(10)
+    ax.fill_between(x, x - 0.2, x + 0.2, alpha=0.2, label="CI band")
+
+    # Legend must include both the seaborn line label and our shaded band label
+    leg = ax.legend()
+    labels = {t.get_text() for t in leg.get_texts()}
+    assert "line" in labels
+    assert "CI band" in labels
 
 
 @pytest.mark.mpl_image_compare

diff --git a/ultraplot/tests/test_legend.py b/ultraplot/tests/test_legend.py
@@ -223,3 +223,62 @@ def test_sync_label_dict(rng):
         0
     ]._legend_dict, "Old legend not removed from dict"
     uplt.close(fig)
+
+
+def test_synthetic_handles_filtered():
+    """
+    Synthetic-tagged helper artists must be ignored by legend parsing even when
+    explicitly passed as handles.
+    """
+    fig, ax = uplt.subplots()
+    (h1,) = ax.plot([0, 1], label="visible")
+    (h2,) = ax.plot([1, 0], label="helper")
+    # Mark helper as synthetic; it should be filtered out from legend entries
+    setattr(h2, "_ultraplot_synthetic", True)
+
+    leg = ax.legend([h1, h2], loc="best")
+    labels = [t.get_text() for t in leg.get_texts()]
+    assert "visible" in labels
+    assert "helper" not in labels
+    uplt.close(fig)
+
+
+def test_fill_between_included_in_legend():
+    """
+    Legitimate fill_between/area handles must appear in legends (regression for
+    previously skipped FillBetweenPolyCollection).
+    """
+    fig, ax = uplt.subplots()
+    x = np.arange(5)
+    y1 = np.zeros(5)
+    y2 = np.ones(5)
+    ax.fill_between(x, y1, y2, label="band")
+
+    leg = ax.legend(loc="best")
+    labels = [t.get_text() for t in leg.get_texts()]
+    assert "band" in labels
+    uplt.close(fig)
+
+
+def test_seaborn_defers_on_the_fly_legend(monkeypatch):
+    """
+    When detected inside a seaborn call, on-the-fly legend creation is deferred
+    (no legend is created until explicitly requested).
+    """
+    fig, ax = uplt.subplots()
+
+    # Force seaborn context detection to True
+    import ultraplot.axes.base as base_mod
+
+    monkeypatch.setattr(base_mod, "_inside_seaborn_call", lambda: True)
+    ax.plot([0, 1], label="a", legend="b")
+
+    # No legend should have been created yet
+    assert getattr(ax[0], "legend_", None) is None
+
+    # Now allow legend creation and explicitly request it
+    monkeypatch.setattr(base_mod, "_inside_seaborn_call", lambda: False)
+    leg = ax.legend(loc="b")
+    labels = [t.get_text() for t in leg.get_texts()]
+    assert "a" in labels
+    uplt.close(fig)