fix(BE): remove space in multi-source string for Elia link

The merged production source was "entsoe.eu, opendata.elia.be" for
hours with storage data. When the app splits source attribution on
"," without trimming, the second name becomes " opendata.elia.be",
which is turned into a broken href with a %20 prefix.

Use a comma without a following space so both source names stay
clean. Same class of bug as #8779 / #8800 (GB) / #8801 (SG); the
comma-space was introduced here in #8787 (b47c731), which started
reporting a combined ENTSO-E/Elia source for hours with storage data.

Updates the BE production snapshot accordingly.

Author: sankalpsthakur

electricitymap/contrib/parsers/BE.py

@@ -203,7 +203,10 @@ def fetch_production(
             end_datetime=event.end_datetime,
             production=event.production,
             storage=storage,
-            source=f"{ENTSOE.SOURCE}, {SOURCE_ELIA}" if storage else SOURCE_ELIA,
+            # No space after comma so source names stay clean when split on ","
+            # (avoids a leading-space " opendata.elia.be" / https://%20… link;
+            # same class of bug as #8779 / #8800 / #8801).
+            source=f"{ENTSOE.SOURCE},{SOURCE_ELIA}" if storage else SOURCE_ELIA,
         )
 
     # Hours where Elia has no data at all: fall back to the full ENTSOE event.

electricitymap/contrib/parsers/tests/__snapshots__/test_BE/test_fetch_production.ambr

@@ -39,7 +39,7 @@
         'unknown': 607.0,
         'wind': 4217.0,
       }),
-      'source': 'entsoe.eu, opendata.elia.be',
+      'source': 'entsoe.eu,opendata.elia.be',
       'sourceType': <EventSourceType.measured: 'measured'>,
       'storage': dict({
         'battery': -25.0,
@@ -62,7 +62,7 @@
         'unknown': 600.66,
         'wind': 4251.79,
       }),
-      'source': 'entsoe.eu, opendata.elia.be',
+      'source': 'entsoe.eu,opendata.elia.be',
       'sourceType': <EventSourceType.measured: 'measured'>,
       'storage': dict({
         'battery': -25.0,
@@ -85,7 +85,7 @@
         'unknown': 591.49,
         'wind': 4266.5,
       }),
-      'source': 'entsoe.eu, opendata.elia.be',
+      'source': 'entsoe.eu,opendata.elia.be',
       'sourceType': <EventSourceType.measured: 'measured'>,
       'storage': dict({
         'battery': -25.0,

electricitymap/contrib/parsers/tests/test_BE.py

@@ -67,7 +67,7 @@ def test_elia_quarters_keep_entsoe_storage(by_datetime):
     # The hourly ENTSOE storage is step-held onto each 15-min slot, incl. pumping
     # (715 MW) which only ENTSOE reports (Elia ods201 has no consumption side).
     for dt in ELIA_QUARTERS:
-        assert by_datetime[dt]["source"] == "entsoe.eu, opendata.elia.be"
+        assert by_datetime[dt]["source"] == "entsoe.eu,opendata.elia.be"
         assert by_datetime[dt]["storage"] == {"battery": -25.0, "hydro": 715.0}