fix market clearing if more supply is available (#214)

tests for verification are added

assume/markets/clearing_algorithms/simple.py

@@ -123,15 +123,17 @@ def clear(
                     gen_vol -= diff
 
                     # add left over to supply_orders again
-                    # supply_orders.insert(0, supply_order)
+                    supply_orders.insert(0, supply_order)
                     demand_order["accepted_volume"] = demand_order["volume"]
                 else:
                     demand_order["accepted_volume"] = demand_order["volume"]
 
                 accepted_demand_orders.append(demand_order)
 
             for order in supply_orders:
-                rejected_orders.append(order)
+                # if the order was not accepted partially, it is rejected
+                if not order.get("accepted_volume"):
+                    rejected_orders.append(order)
 
             # set clearing price - merit order - uniform pricing
             if accepted_supply_orders:

tests/test_simple_market_mechanisms.py

@@ -106,9 +106,75 @@ def test_market_pay_as_clear():
     orderbook = extend_orderbook(products, 300, 100, orderbook)
     orderbook = extend_orderbook(products, 200, 50, orderbook)
 
+    mr = PayAsClearRole(simple_dayahead_auction_config)
+    accepted, rejected, meta = mr.clear(orderbook, products)
+    assert meta[0]["demand_volume"] > 0
+    assert meta[0]["price"] > 0
+    assert len(accepted) == 4
+    assert len(rejected) == 0
+    assert meta[0]["supply_volume"] == 500
+    assert meta[0]["demand_volume"] == 500
+    assert meta[0]["price"] == 100
+    for bid in accepted:
+        assert bid["volume"] == bid["accepted_volume"]
+
+
+def test_market_pay_as_clears_single_demand():
+    next_opening = simple_dayahead_auction_config.opening_hours.after(datetime.now())
+    products = get_available_products(
+        simple_dayahead_auction_config.market_products, next_opening
+    )
+    assert len(products) == 1
+
+    """
+    Create Orderbook with constant order volumes and prices:
+        - dem1: volume = -1000, price = 3000
+        - gen1: volume = 1000, price = 100
+        - gen2: volume = 900, price = 50
+    """
+    orderbook = extend_orderbook(products, -700, 3000)
+    orderbook = extend_orderbook(products, 300, 100, orderbook)
+    orderbook = extend_orderbook(products, 200, 50, orderbook)
+
+    mr = PayAsClearRole(simple_dayahead_auction_config)
+    accepted, rejected, meta = mr.clear(orderbook, products)
+    assert meta[0]["demand_volume"] > 0
+    assert meta[0]["price"] > 0
+    assert len(accepted) == 3
+    assert len(rejected) == 0
+    assert meta[0]["supply_volume"] == 500
+    assert meta[0]["demand_volume"] == 500
+    assert meta[0]["price"] == 100
+    assert accepted[0]["volume"] == -700
+    assert accepted[0]["accepted_volume"] == -500
+
+
+def test_market_pay_as_clears_single_demand_more_generation():
+    next_opening = simple_dayahead_auction_config.opening_hours.after(datetime.now())
+    products = get_available_products(
+        simple_dayahead_auction_config.market_products, next_opening
+    )
+    assert len(products) == 1
+
+    """
+    Create Orderbook with constant order volumes and prices:
+        - dem1: volume = -1000, price = 3000
+        - gen1: volume = 1000, price = 100
+        - gen2: volume = 900, price = 50
+    """
+    orderbook = extend_orderbook(products, -400, 3000)
+    orderbook = extend_orderbook(products, 300, 100, orderbook)
+    orderbook = extend_orderbook(products, 200, 50, orderbook)
+    orderbook = extend_orderbook(products, 230, 60, orderbook)
+
     mr = PayAsClearRole(simple_dayahead_auction_config)
     accepted, rejected, meta = mr.clear(orderbook, products)
     assert meta[0]["demand_volume"] > 0
     assert meta[0]["price"] > 0
     assert len(accepted) == 3
     assert len(rejected) == 1
+    assert meta[0]["supply_volume"] == 400
+    assert meta[0]["demand_volume"] == 400
+    assert meta[0]["price"] == 60
+    assert accepted[0]["volume"] == -400
+    assert accepted[0]["accepted_volume"] == -400