Fix tenure listing

server-rs/src/data/actual_listings.rs

@@ -1,6 +1,6 @@
 use std::path::Path;
 
-use anyhow::{Context, Result};
+use anyhow::{bail, Context, Result};
 use polars::lazy::frame::LazyFrame;
 use polars::prelude::*;
 use serde::Serialize;
@@ -12,6 +12,19 @@ use crate::utils::{normalize_postcode, GridIndex, InternedColumn};
 
 const GRID_CELL_SIZE: f32 = 0.01;
 
+/// Features `build_filter_feature_data` stamps on from the listing's own fields
+/// after reading the parquet, so their absence as a column is expected.
+const OVERLAID_LISTING_FEATURES: &[&str] = &[
+    "Total floor area (sqm)",
+    "Number of bedrooms & living rooms",
+    "Estimated current price",
+    "Last known price",
+    "Est. price per sqm",
+    "Price per sqm",
+    "Property type",
+    "Leasehold/Freehold",
+];
+
 /// One observation on a listing's accruing asking-price timeline, recovered from
 /// the scraper's forward-only store (finder/price_history.py). `reason` is one of
 /// "listed" | "reduced" | "increased"; `date` is `YYYY-MM-DD`.
@@ -215,19 +228,44 @@ fn build_filter_feature_data(
     let mut feature_data = vec![NAN_U16; row_count * num_features];
     let quant = property_data.quant_ref();
     let mut encoded_columns = 0usize;
+    let mut missing_columns: Vec<&str> = Vec::new();
 
     for (feat_idx, name) in property_data.feature_names.iter().enumerate() {
         if feat_idx < property_data.num_numeric {
             if let Some(values) = extract_optional_feature_f32(df, name)? {
                 encode_numeric_feature(&mut feature_data, property_data, &quant, feat_idx, values);
                 encoded_columns += 1;
+            } else {
+                missing_columns.push(name);
             }
         } else if let Some(values) = extract_optional_feature_str(df, name)? {
             encode_enum_feature(&mut feature_data, property_data, feat_idx, values);
             encoded_columns += 1;
+        } else {
+            missing_columns.push(name);
         }
     }
 
+    // A feature the enriched parquet doesn't carry stays NAN_U16 for every row,
+    // and filtering on it then rejects every listing (see
+    // `row_passes_listing_filters`), so refuse to boot rather than serve a
+    // filter that silently matches nothing. This mirrors the combined-schema
+    // check in `data/property/loading.rs`, whose absence here is what let the
+    // council columns ship missing. The overlay features are exempt: they are
+    // stamped on from the listing's own fields straight after this loop.
+    let missing_columns: Vec<&str> = missing_columns
+        .into_iter()
+        .filter(|name| !OVERLAID_LISTING_FEATURES.contains(name))
+        .collect();
+    if !missing_columns.is_empty() {
+        bail!(
+            "Configured features {:?} not found in the enriched listings parquet. \
+             Filtering on them would match no listings. Rebuild it with \
+             `make -f Makefile.data enrich-actual-listings`.",
+            missing_columns
+        );
+    }
+
     overlay_numeric_feature(
         &mut feature_data,
         property_data,
@@ -745,6 +783,43 @@ mod tests {
         assert!(!any_listing.listing_url.is_empty());
     }
 
+    fn property_data_declaring(feature: &str) -> PropertyData {
+        let mut property_data = PropertyData::empty_for_tests();
+        property_data.feature_names = vec![feature.to_string()];
+        property_data.num_features = 1;
+        property_data.num_numeric = 1;
+        property_data
+    }
+
+    fn build_matrix_for(property_data: &PropertyData, df: &DataFrame) -> Result<Vec<u16>> {
+        build_filter_feature_data(df, Some(property_data), &[], &[], &[], &[], &[], &[])
+    }
+
+    #[test]
+    fn rejects_listings_parquet_missing_a_declared_feature() {
+        // A declared column the parquet lacks would stay NAN_U16 for every row,
+        // and `row_passes_listing_filters` would then reject every listing. Fail
+        // the boot instead of serving a filter that matches nothing.
+        let df = df!("Some other column" => [1.0f64]).expect("frame");
+        let property_data = property_data_declaring("% Council housing");
+
+        let error = build_matrix_for(&property_data, &df).expect_err("must reject");
+
+        let message = error.to_string();
+        assert!(message.contains("% Council housing"), "{message}");
+        assert!(message.contains("enrich-actual-listings"), "{message}");
+    }
+
+    #[test]
+    fn accepts_overlaid_features_absent_from_the_parquet() {
+        // The overlay features are stamped on from the listing's own fields
+        // after the read, so their absence as a column is expected, not fatal.
+        let df = df!("Some other column" => [1.0f64]).expect("frame");
+        let property_data = property_data_declaring(OVERLAID_LISTING_FEATURES[0]);
+
+        build_matrix_for(&property_data, &df).expect("overlaid feature must not be fatal");
+    }
+
     #[test]
     fn extracts_price_history_from_parquet() {
         let path = PathBuf::from("src/data/testdata/listings_price_history.parquet");