start off the blueprints

core/dbt/exceptions.py

@@ -296,6 +296,17 @@ class UndefinedMacroException(CompilationException):
         )
 
 
+# TODO: create a new class that displays in the terminal that a data type config is missing/wrong
+class UndefinedDataTypeException(CompilationException):
+    def __str__(self, prefix="! ") -> str:
+        msg = super().__str__(prefix)
+        return (
+            f"{msg}. This can happen when a data_type configuration does "
+            "not exist or is defined as null when `constraints_enabled: true` for a dbt model. \
+            Check for typos and/or verify data_type is defined for all columns for the dbt models with constraints. "
+        )
+
+
 class UnknownAsyncIDException(Exception):
     CODE = 10012
     MESSAGE = "RPC server got an unknown async ID"

core/dbt/parser/generic_test_builders.py

@@ -180,6 +180,7 @@ class GenericTestBlock(TestBlock[Testable], Generic[Testable]):
         )
 
 
+# TODO: create a ConstraintsBuilder equivalent
 class TestBuilder(Generic[Testable]):
     """An object to hold assorted test settings and perform basic parsing
 
@@ -194,6 +195,7 @@ class TestBuilder(Generic[Testable]):
         r"((?P<test_namespace>([a-zA-Z_][0-9a-zA-Z_]*))\.)?"
         r"(?P<test_name>([a-zA-Z_][0-9a-zA-Z_]*))"
     )
+    # TODO: add config args like: "default", "data_type", "constraint", "check"
     # args in the test entry representing test configs
     CONFIG_ARGS = (
         "severity",

core/dbt/parser/schemas.py

@@ -169,6 +169,7 @@ def _trimmed(inp: str) -> str:
     return inp[:44] + "..." + inp[-3:]
 
 
+# TODO: I'll likely need to add a ConstraintsBuilder class similar to TestBuilder within SchemaParser
 class SchemaParser(SimpleParser[GenericTestBlock, ParsedGenericTestNode]):
     def __init__(
         self,