fix: catch jinja typeerrors during render phase

.changes/unreleased/Fixes-20241017-174435.yaml

@@ -0,0 +1,6 @@
+kind: Fixes
+body: catch jinja type errors during render phase
+time: 2024-10-17T17:44:35.736867874-03:00
+custom:
+    Author: devmessias
+    Issue: "206"

dbt_common/clients/jinja.py

@@ -46,6 +46,7 @@
     MaterializationArgError,
     JinjaRenderingError,
     UndefinedCompilationError,
+    DbtRuntimeTypeError,
 )
 from dbt_common.exceptions.macros import MacroReturn, UndefinedMacroError, CaughtMacroError
 
@@ -125,6 +126,14 @@ def _compile(self, source: str, filename: str) -> CodeType:
         return super()._compile(source, filename)  # type: ignore
 
 
+class RenderCallJinjaTypeError(jinja2.TemplateError):
+    def __init__(
+        self,
+        message: str,
+    ) -> None:
+        super().__init__(message)
+
+
 class MacroFuzzTemplate(jinja2.nativetypes.NativeTemplate):
     environment_class = MacroFuzzEnvironment  # type: ignore
 
@@ -159,6 +168,8 @@ def render(self, *args: Any, **kwargs: Any) -> Any:
             return self.environment_class.concat(  # type: ignore
                 self.root_render_func(ctx)  # type: ignore
             )
+        except TypeError as e:
+            raise RenderCallJinjaTypeError(str(e)) from e
         except Exception:
             return self.environment.handle_exception()
 
@@ -531,6 +542,8 @@ def catch_jinja(node: Optional[_NodeProtocol] = None) -> Iterator[None]:
         raise CompilationError(str(e), node) from e
     except jinja2.exceptions.UndefinedError as e:
         raise UndefinedMacroError(str(e), node) from e
+    except RenderCallJinjaTypeError as e:
+        raise DbtRuntimeTypeError(str(e), node) from e
     except CompilationError as exc:
         exc.add_node(node)
         raise

dbt_common/exceptions/base.py

@@ -272,3 +272,11 @@ def __str__(self, prefix: str = "! ") -> str:
         if len(self.cmd) == 0:
             return f"{self.msg}: No arguments given"
         return f'{self.msg}: "{self.cmd[0]}"'
+
+
+class DbtRuntimeTypeError(DbtRuntimeError):
+    MESSAGE = "Type Error"
+
+    @property
+    def type(self):
+        return "Type"

tests/unit/test_jinja.py

@@ -2,7 +2,7 @@
 
 from dbt_common.clients._jinja_blocks import BlockTag
 from dbt_common.clients.jinja import extract_toplevel_blocks, get_template, render_template
-from dbt_common.exceptions import CompilationError
+from dbt_common.exceptions import CompilationError, DbtRuntimeTypeError
 
 
 class TestBlockLexer(unittest.TestCase):
@@ -447,6 +447,44 @@ def test_if_endfor_newlines(self) -> None:
         )
 
 
+class TestRenderExceptions(unittest.TestCase):
+    def _dummy_config(self, something: str) -> int:
+        return int(something == "foo")
+
+    def test_no_type_error(self) -> None:
+        jinja_string = 'select {{config(something="foo")}} + {{number}} as result'
+        ctx = {"config": self._dummy_config, "number": 1}
+
+        template = get_template(jinja_string, ctx)
+        rendered = render_template(template, ctx)
+        assert "select 1 + 1 as result" == rendered
+
+    def test_type_error(self) -> None:
+        jinja_string = 'select {{config(something=-"foo")}} as result'
+        ctx = {"config": self._dummy_config}
+
+        template = get_template(jinja_string, ctx)
+        with self.assertRaises(DbtRuntimeTypeError):
+            render_template(template, ctx)
+
+    def test_type_error_iter_none(self) -> None:
+        jinja_string = """
+        {% set mylist = None %}
+
+        {% for item in mylist %}
+
+        select '{{ item }}' as my_item
+        {{ 'union all' if not loop.last }}
+
+        {% endfor %}
+        """
+        ctx = {"config": self._dummy_config}
+
+        template = get_template(jinja_string, ctx)
+        with self.assertRaises(DbtRuntimeTypeError):
+            render_template(template, ctx)
+
+
 bar_block = """{% mytype bar %}
 {# a comment
     that inside it has