map funcs

src/ytdl_sub/script/functions/map_functions.py

@@ -3,6 +3,7 @@ from typing import Optional
 from ytdl_sub.script.types.map import Map
 from ytdl_sub.script.types.resolvable import AnyArgument
 from ytdl_sub.script.types.resolvable import Hashable
+from ytdl_sub.script.utils.exceptions import KeyDoesNotExistRuntimeException
 
 
 class MapFunctions:
@@ -12,6 +13,11 @@ class MapFunctions:
         Return ``key``'s value within the Map. If ``key`` does not exist, and ``default`` is
         provided, it will return ``default``. Otherwise, will error.
         """
-        if default is not None:
+        if key not in mapping.value:
-            return mapping.value.get(key, default=default)
+            if default is not None:
+                return default
+
+            raise KeyDoesNotExistRuntimeException(
+                f"Tried to call %map_get with key {key.value}, but it does not exist"
+            )
         return mapping.value[key]

src/ytdl_sub/script/types/function.py

@@ -26,6 +26,7 @@ from ytdl_sub.script.types.variable_dependency import VariableDependency
 from ytdl_sub.script.utils.exception_formatters import FunctionArgumentsExceptionFormatter
 from ytdl_sub.script.utils.exceptions import UNREACHABLE
 from ytdl_sub.script.utils.exceptions import FunctionRuntimeException
+from ytdl_sub.script.utils.exceptions import RuntimeException
 from ytdl_sub.script.utils.exceptions import UserThrownRuntimeError
 from ytdl_sub.script.utils.type_checking import FunctionSpec
 from ytdl_sub.script.utils.type_checking import is_union
@@ -189,7 +190,7 @@ class BuiltInFunction(Function, BuiltInFunctionType):
 
         try:
             return self.callable(*resolved_arguments)
-        except UserThrownRuntimeError:
+        except (UserThrownRuntimeError, RuntimeException):
             raise
         except Exception as exc:
             raise FunctionRuntimeException(

src/ytdl_sub/script/utils/exceptions.py

@@ -2,15 +2,14 @@ from abc import ABC
 
 from ytdl_sub.utils.exceptions import ValidationException
 
+###################################################################################################
+# USER EXCEPTIONS
+
 
 class UserException(ValidationException, ABC):
     """It's the user's fault!"""
 
 
-class RuntimeException(ValueError, ABC):
-    """Exception thrown at runtime during resolution"""
-
-
 class InvalidSyntaxException(UserException):
     """Syntax is incorrect"""
 
@@ -47,18 +46,6 @@ class CycleDetected(UserException):
     """A cycle exists within a user's script"""
 
 
-class FunctionRuntimeException(RuntimeException):
-    """Exception thrown when a ytdl-sub function has an error occur at runtime"""
-
-
-class KeyNotHashableRuntimeException(RuntimeException):
-    """Map tried to use a non-hashable key at runtime"""
-
-
-class FunctionDoesNotExistRuntimeException(RuntimeException):
-    """Tried to get a function that does not exist"""
-
-
 class UserThrownRuntimeError(ValidationException):
     """An error explicitly thrown by the user via a function"""
 
@@ -72,3 +59,26 @@ UNREACHABLE = _UnreachableSyntaxException(
     "Please upload your config/subscription file(s) to and make a GitHub issue at "
     "https://github.com/jmbannon/ytdl-sub/issues"
 )
+
+###################################################################################################
+# RUNTIME EXCEPTIONS
+
+
+class RuntimeException(ValueError, ABC):
+    """Exception thrown at runtime during resolution"""
+
+
+class FunctionRuntimeException(RuntimeException):
+    """Exception thrown when a ytdl-sub function has an error occur at runtime"""
+
+
+class KeyNotHashableRuntimeException(RuntimeException):
+    """Map tried to use a non-hashable key at runtime"""
+
+
+class FunctionDoesNotExistRuntimeException(RuntimeException):
+    """Tried to get a function that does not exist"""
+
+
+class KeyDoesNotExistRuntimeException(RuntimeException):
+    """Tried to access a key on a map that does not exist, with no default"""

tests/unit/script/functions/test_map_functions.py

@@ -0,0 +1,48 @@
+import re
+
+import pytest
+
+from ytdl_sub.script.script import Script
+from ytdl_sub.script.utils.exceptions import KeyDoesNotExistRuntimeException
+
+
+class TestMapFunctions:
+    def test_map_get(self):
+        output = (
+            Script(
+                {
+                    "input_map": "{{'key': 'value'}}",
+                    "output": "{%map_get(input_map, 'key')}",
+                }
+            )
+            .resolve(update=True)
+            .get("output")
+            .native
+        )
+        assert output == "value"
+
+    def test_map_get_optional(self):
+        output = (
+            Script(
+                {
+                    "input_map": "{{'key': 'value'}}",
+                    "output": "{%map_get(input_map, 'dne', 'optional_value')}",
+                }
+            )
+            .resolve(update=True)
+            .get("output")
+            .native
+        )
+        assert output == "optional_value"
+
+    def test_map_get_errors_missing_key(self):
+        with pytest.raises(
+            KeyDoesNotExistRuntimeException,
+            match=re.escape("Tried to call %map_get with key dne, but it does not exist"),
+        ):
+            Script(
+                {
+                    "input_map": "{{'key': 'value'}}",
+                    "output": "{%map_get(input_map, 'dne')}",
+                }
+            ).resolve()