split node tests into standalone files

tests/node_tests/test_histogram.py

@@ -0,0 +1,40 @@
+import numpy as np
+from tests.node_tests._shared import make_field
+
+
+def test_height_histogram():
+    from backend.nodes.histogram import Histogram
+    node = Histogram()
+
+    data = np.linspace(0, 1, 1000).reshape(25, 40)
+    field = make_field(data=data)
+
+    overlays = []
+    Histogram._broadcast_overlay_fn = lambda nid, data: overlays.append(data)
+    Histogram._current_node_id = "test"
+
+    table, coord_pair = node.process(field, n_bins=10, y_scale="linear", x1=0.2, y1=0.5, x2=0.8, y2=0.5)
+    assert isinstance(coord_pair, tuple) and len(coord_pair) == 2
+    measurements = {row["quantity"]: row for row in table}
+    assert "A position" in measurements
+    assert "A count" in measurements
+    assert "B position" in measurements
+    assert "B count" in measurements
+    assert "delta X" in measurements
+    assert "delta Y" in measurements
+    assert measurements["A count"]["unit"] == "count"
+    assert measurements["B count"]["unit"] == "count"
+    assert measurements["B position"]["value"] > measurements["A position"]["value"]
+    assert len(overlays) == 1
+    assert overlays[0]["kind"] == "line_plot"
+    assert overlays[0]["section_title"] == "Histogram"
+    assert len(overlays[0]["line"]) == 10
+    assert len(overlays[0]["x_axis"]) == 10
+    assert np.isclose(overlays[0]["x1"], 0.2)
+    assert np.isclose(overlays[0]["x2"], 0.8)
+    assert np.isclose(
+        measurements["delta Y"]["value"],
+        measurements["B count"]["value"] - measurements["A count"]["value"],
+    )
+
+    Histogram._broadcast_overlay_fn = None