SPlit up

pipeline/download/test_rental_prices.py

@@ -6,13 +6,13 @@ from pipeline.download.rental_prices import _latest_rents_long
 def test_latest_rents_long_adds_iod_alias_codes_for_south_yorkshire():
     raw = pl.DataFrame(
         {
-            "column_1": ["title", "header", "2026-02-01 00:00:00"],
-            "column_2": ["", "", "E08000038"],
-            "column_3": ["", "", "Barnsley"],
-            "column_12": ["", "", "486"],
-            "column_16": ["", "", "595"],
-            "column_20": ["", "", "705"],
-            "column_24": ["", "", "900"],
+            "column_1": ["title", "Time period", "2026-02-01 00:00:00"],
+            "column_2": ["", "Area code", "E08000038"],
+            "column_3": ["", "Area name", "Barnsley"],
+            "column_12": ["", "One bed", "486"],
+            "column_16": ["", "Two bed", "595"],
+            "column_20": ["", "Three bed", "705"],
+            "column_24": ["", "Four or more bed", "900"],
         }
     )
 
@@ -22,3 +22,30 @@ def test_latest_rents_long_adds_iod_alias_codes_for_south_yorkshire():
         {"area_code": "E08000016", "mean_monthly_rent": 486.0},
         {"area_code": "E08000038", "mean_monthly_rent": 486.0},
     ]
+
+
+def test_latest_rents_long_locates_header_in_variable_preamble():
+    """The live workbook has THREE preamble rows (title, contents note,
+    header); a fixed two-row slice left the header in the data and only the
+    area-code filter happened to drop it."""
+    raw = pl.DataFrame(
+        {
+            "column_1": [
+                "title",
+                "This worksheet contains one table.",
+                "Time period",
+                "2026-02-01 00:00:00",
+            ],
+            "column_2": ["", "", "Area code", "E08000038"],
+            "column_3": ["", "", "Area name", "Barnsley"],
+            "column_12": ["", "", "One bed", "486"],
+            "column_16": ["", "", "Two bed", "595"],
+            "column_20": ["", "", "Three bed", "705"],
+            "column_24": ["", "", "Four or more bed", "900"],
+        }
+    )
+
+    result = _latest_rents_long(raw)
+
+    assert result.filter(pl.col("area_code") == "E08000038").height == 5
+    assert result["mean_monthly_rent"].null_count() == 0