Handle comparable string edge case

hotprices_au/sites/coles.py

@@ -144,12 +144,37 @@ def get_quantity_and_unit(item):
         # If that didn't work we can now try to get the info from standard sizes (e.g. per 100g)
         if 'ofMeasureUnits' in unit_data:
             unit = unit_data['ofMeasureUnits']
+        elif item.get('pricing',{}).get('comparable'):
+            return parse_comparable(item)
         else:
             raise
 
     return quantity, unit
 
 
+def parse_comparable(item):
+    comparable = item['pricing']['comparable']
+    m = re.match(r'\$([\.0-9]+) per (.*)', comparable)
+    if not m:
+        raise RuntimeError(f"Unable to parse comparable {comparable}")
+
+    price_str, per_str = m.group(1), m.group(2)
+    price_per = float(price_str)
+    if price_per != item['pricing']['now']:
+        raise RuntimeError(
+            f"Price from {comparable} extracted as {price_per} "
+            f"does not match expected price of {item['pricing']['now']}"
+        )
+
+    if per_str == '1ea':
+        quantity, unit = 1, 'ea'
+    else:
+        raise RuntimeError(
+            f"Unable to understad what {per_str} means from "
+            f"{comparable}"
+        )
+    return quantity, unit
+
 def parse_str_unit(size):
     # Try coles-special methods before going to the generic function
     size = size.lower()

tests/stores/test_coles.py

@@ -1,6 +1,7 @@
 from hotprices_au.sites import coles
 
-def get_item(ofMeasureUnits=None, quantity=None, isWeighted=True, pricing=True, size=None, **kwargs):
+def get_item(ofMeasureUnits=None, quantity=None, isWeighted=True, pricing=True,
+             size=None, comparable=None, **kwargs):
     defaults = {
         '_type': 'PRODUCT',
         'id': '1',
@@ -26,6 +27,9 @@ def get_item(ofMeasureUnits=None, quantity=None, isWeighted=True, pricing=True,
     if quantity is not None:
         defaults['pricing']['unit']['quantity'] = quantity
 
+    if comparable is not None:
+        defaults['pricing']['comparable'] = comparable
+
     if pricing is None:
         defaults['pricing'] = None
     defaults.update(kwargs)
@@ -133,6 +137,12 @@ def test_get_canonical():
     assert can_item['quantity'] == 200
     assert not can_item['isWeighted']
 
+    item = get_item(comparable='$10.00 per 1ea', quantity=0)
+    can_item = coles.get_canonical(item, today)
+    assert can_item['unit'] == 'ea'
+    assert can_item['quantity'] == 1
+    assert can_item['price'] == 10
+
 
 if __name__ == '__main__':
     test_get_canonical()