Test: Add case with typed parsing

tests/test_parse_json.liq

@@ -20,19 +20,27 @@
 
 %include "base_config.liq"
 
-# Submitted bug report: https://github.com/savonet/liquidsoap/issues/2483
+# Compare: https://github.com/savonet/liquidsoap/issues/2483
 
 # Scenario 1: Doesn't work
 let json.parse data = '{"show_id": "-1", "show_name": "Random Music"}'
 print("Set current show to '#{data.show_name}' (ID: #{data.show_id})")
 # > Set current show to 'null' (ID: null)
 
-# Scenario 2: Works
+# Scenario 2: Works, when data types of the JSON have been defined
+let json.parse (data : {
+        show_id: string,
+        show_name: string
+    }) = '{"show_id": "-1", "show_name": "Random Music"}'
+print("Set current show to '#{data.show_name}' (ID: #{data.show_id})")
+# # > Set current show to 'Random Music' (ID: -1)
+
+# Scenario 3: Works, even when no data types have been defined
 let json.parse data = '{"show_id": "-1", "show_name": "Random Music"}'
 print("Set current show to '" ^ data.show_name ^ "' (ID: " ^ data.show_id ^ ")")
-# > Set current show to 'Random Music' (ID: -1)
+# # > Set current show to 'Random Music' (ID: -1)
 
-# Scenario 3: Works, when variables have been accessed outside the string before
+# Scenario 4: Works, when variables have been accessed outside the string before
 let json.parse data = '{"show_id": "-1", "show_name": "Random Music"}'
 print("Set current show to '" ^ data.show_name ^ "' (ID: " ^ data.show_id ^ ")")
 print("Set current show to '#{data.show_name}' (ID: #{data.show_id})")