test: add tests for segment joining function

prereise/gather/griddata/hifld/data_access/tests/test_load.py

@@ -0,0 +1,78 @@
+from prereise.gather.griddata.hifld.data_access.load import _join_line_segments
+
+
+def test_join_line_segments_single_segment():
+    # Seattle to Tacoma via Seatac
+    segments = [[(-122.34, 47.60), (-122.30, 47.44), (-122.44, 47.25)]]
+    assert _join_line_segments(segments) is segments[0]
+
+
+def test_join_line_segments_single_segment_after_filtering():
+    segments = [
+        # Long line with extremely similar start & end in Tacoma, should get filtered
+        [(-122.45, 47.24), (-122.90, 47.04), (-122.45, 47.240001)],
+        # Seattle to Tacoma via Seatac
+        [(-122.34, 47.60), (-122.30, 47.44), (-122.44, 47.25)],
+    ]
+    assert _join_line_segments(segments) is segments[1]
+
+
+def test_join_line_segments_two_segments():
+    segments = [
+        # Seattle to Tacoma via Seatac
+        [(-122.34, 47.60), (-122.30, 47.44), (-122.44, 47.25)],
+        # Olympia to a slightly different point in Tacoma
+        [(-122.90, 47.04), (-122.45, 47.24)],
+    ]
+    joined_segments = _join_line_segments(segments)
+    assert joined_segments == [
+        (-122.34, 47.60),
+        (-122.30, 47.44),
+        (-122.44, 47.25),
+        (-122.45, 47.24),
+        (-122.90, 47.04),
+    ]
+
+
+def test_join_line_segments_three_segments():
+    segments = [
+        # Olympia to Tacoma
+        [(-122.90, 47.04), (-122.45, 47.24)],
+        # Seattle to a slightly different point in Tacoma via Seatac
+        [(-122.34, 47.60), (-122.30, 47.44), (-122.44, 47.25)],
+        # Seattle (exact same point) to Everett
+        [(-122.34, 47.60), (-122.18, 47.99)],
+    ]
+    joined_segments = _join_line_segments(segments)
+    assert joined_segments == [
+        (-122.90, 47.04),
+        (-122.45, 47.24),
+        (-122.44, 47.25),
+        (-122.30, 47.44),
+        (-122.34, 47.60),
+        (-122.34, 47.60),
+        (-122.18, 47.99),
+    ]
+
+
+def test_join_line_segments_four_segments_non_linear():
+    segments = [
+        # Olympia to Tacoma
+        [(-122.90, 47.04), (-122.45, 47.24)],
+        # Seattle to Bellevue via Kenmore (should be dropped)
+        [(-122.34, 47.60), (-122.253, 47.755), (-122.195, 47.603)],
+        # Seattle to a slightly different point in Tacoma via Seatac
+        [(-122.34, 47.60), (-122.30, 47.44), (-122.44, 47.25)],
+        # Seattle (exact same point) to Everett
+        [(-122.34, 47.60), (-122.18, 47.99)],
+    ]
+    joined_segments = _join_line_segments(segments)
+    assert joined_segments == [
+        (-122.90, 47.04),
+        (-122.45, 47.24),
+        (-122.44, 47.25),
+        (-122.30, 47.44),
+        (-122.34, 47.60),
+        (-122.34, 47.60),
+        (-122.18, 47.99),
+    ]