Move BaseConfig to Common (#9224)

* moving types_pb2.py to common/events

* move BaseConfig and assorted dependencies to common

* move ShowBehavior and OnConfigurationChange to common

* add changie

.changes/unreleased/Under the Hood-20231205-185022.yaml

@@ -0,0 +1,7 @@
+kind: Under the Hood
+body: Move BaseConfig, Metadata and various other contract classes from model_config
+  to common/contracts/config
+time: 2023-12-05T18:50:22.321229-08:00
+custom:
+  Author: colin-rorgers-dbt
+  Issue: "8919"

core/dbt/adapters/protocol.py

@@ -6,7 +6,7 @@
 
 from dbt.adapters.contracts.connection import Connection, AdapterRequiredConfig, AdapterResponse
 from dbt.adapters.contracts.relation import Policy, HasQuoting, RelationConfig
-from dbt.contracts.graph.model_config import BaseConfig
+from dbt.common.contracts.config.base import BaseConfig
 from dbt.contracts.graph.manifest import Manifest
 
 

core/dbt/common/contracts/config/base.py

@@ -0,0 +1,259 @@
+from dataclasses import dataclass, Field
+
+from itertools import chain
+from typing import Callable, Dict, Any, List, TypeVar
+
+from dbt.common.contracts.config.metadata import Metadata
+from dbt.common.exceptions import CompilationError, DbtInternalError
+from dbt.common.contracts.config.properties import AdditionalPropertiesAllowed
+from dbt.contracts.util import Replaceable
+
+T = TypeVar("T", bound="BaseConfig")
+
+
+@dataclass
+class BaseConfig(AdditionalPropertiesAllowed, Replaceable):
+    # enable syntax like: config['key']
+    def __getitem__(self, key):
+        return self.get(key)
+
+    # like doing 'get' on a dictionary
+    def get(self, key, default=None):
+        if hasattr(self, key):
+            return getattr(self, key)
+        elif key in self._extra:
+            return self._extra[key]
+        else:
+            return default
+
+    # enable syntax like: config['key'] = value
+    def __setitem__(self, key, value):
+        if hasattr(self, key):
+            setattr(self, key, value)
+        else:
+            self._extra[key] = value
+
+    def __delitem__(self, key):
+        if hasattr(self, key):
+            msg = (
+                'Error, tried to delete config key "{}": Cannot delete ' "built-in keys"
+            ).format(key)
+            raise CompilationError(msg)
+        else:
+            del self._extra[key]
+
+    def _content_iterator(self, include_condition: Callable[[Field], bool]):
+        seen = set()
+        for fld, _ in self._get_fields():
+            seen.add(fld.name)
+            if include_condition(fld):
+                yield fld.name
+
+        for key in self._extra:
+            if key not in seen:
+                seen.add(key)
+                yield key
+
+    def __iter__(self):
+        yield from self._content_iterator(include_condition=lambda f: True)
+
+    def __len__(self):
+        return len(self._get_fields()) + len(self._extra)
+
+    @staticmethod
+    def compare_key(
+        unrendered: Dict[str, Any],
+        other: Dict[str, Any],
+        key: str,
+    ) -> bool:
+        if key not in unrendered and key not in other:
+            return True
+        elif key not in unrendered and key in other:
+            return False
+        elif key in unrendered and key not in other:
+            return False
+        else:
+            return unrendered[key] == other[key]
+
+    @classmethod
+    def same_contents(cls, unrendered: Dict[str, Any], other: Dict[str, Any]) -> bool:
+        """This is like __eq__, except it ignores some fields."""
+        seen = set()
+        for fld, target_name in cls._get_fields():
+            key = target_name
+            seen.add(key)
+            if CompareBehavior.should_include(fld):
+                if not cls.compare_key(unrendered, other, key):
+                    return False
+
+        for key in chain(unrendered, other):
+            if key not in seen:
+                seen.add(key)
+                if not cls.compare_key(unrendered, other, key):
+                    return False
+        return True
+
+    # This is used in 'add_config_call' to create the combined config_call_dict.
+    # 'meta' moved here from node
+    mergebehavior = {
+        "append": ["pre-hook", "pre_hook", "post-hook", "post_hook", "tags"],
+        "update": [
+            "quoting",
+            "column_types",
+            "meta",
+            "docs",
+            "contract",
+        ],
+        "dict_key_append": ["grants"],
+    }
+
+    @classmethod
+    def _merge_dicts(cls, src: Dict[str, Any], data: Dict[str, Any]) -> Dict[str, Any]:
+        """Find all the items in data that match a target_field on this class,
+        and merge them with the data found in `src` for target_field, using the
+        field's specified merge behavior. Matching items will be removed from
+        `data` (but _not_ `src`!).
+
+        Returns a dict with the merge results.
+
+        That means this method mutates its input! Any remaining values in data
+        were not merged.
+        """
+        result = {}
+
+        for fld, target_field in cls._get_fields():
+            if target_field not in data:
+                continue
+
+            data_attr = data.pop(target_field)
+            if target_field not in src:
+                result[target_field] = data_attr
+                continue
+
+            merge_behavior = MergeBehavior.from_field(fld)
+            self_attr = src[target_field]
+
+            result[target_field] = _merge_field_value(
+                merge_behavior=merge_behavior,
+                self_value=self_attr,
+                other_value=data_attr,
+            )
+        return result
+
+    def update_from(self: T, data: Dict[str, Any], adapter_type: str, validate: bool = True) -> T:
+        """Given a dict of keys, update the current config from them, validate
+        it, and return a new config with the updated values
+        """
+        # sadly, this is a circular import
+        from dbt.adapters.factory import get_config_class_by_name
+
+        dct = self.to_dict(omit_none=False)
+
+        adapter_config_cls = get_config_class_by_name(adapter_type)
+
+        self_merged = self._merge_dicts(dct, data)
+        dct.update(self_merged)
+
+        adapter_merged = adapter_config_cls._merge_dicts(dct, data)
+        dct.update(adapter_merged)
+
+        # any remaining fields must be "clobber"
+        dct.update(data)
+
+        # any validation failures must have come from the update
+        if validate:
+            self.validate(dct)
+        return self.from_dict(dct)
+
+    def finalize_and_validate(self: T) -> T:
+        dct = self.to_dict(omit_none=False)
+        self.validate(dct)
+        return self.from_dict(dct)
+
+
+class MergeBehavior(Metadata):
+    Append = 1
+    Update = 2
+    Clobber = 3
+    DictKeyAppend = 4
+
+    @classmethod
+    def default_field(cls) -> "MergeBehavior":
+        return cls.Clobber
+
+    @classmethod
+    def metadata_key(cls) -> str:
+        return "merge"
+
+
+class CompareBehavior(Metadata):
+    Include = 1
+    Exclude = 2
+
+    @classmethod
+    def default_field(cls) -> "CompareBehavior":
+        return cls.Include
+
+    @classmethod
+    def metadata_key(cls) -> str:
+        return "compare"
+
+    @classmethod
+    def should_include(cls, fld: Field) -> bool:
+        return cls.from_field(fld) == cls.Include
+
+
+def _listify(value: Any) -> List:
+    if isinstance(value, list):
+        return value[:]
+    else:
+        return [value]
+
+
+# There are two versions of this code. The one here is for config
+# objects, the one in _add_config_call in core context_config.py is for
+# config_call_dict dictionaries.
+def _merge_field_value(
+    merge_behavior: MergeBehavior,
+    self_value: Any,
+    other_value: Any,
+):
+    if merge_behavior == MergeBehavior.Clobber:
+        return other_value
+    elif merge_behavior == MergeBehavior.Append:
+        return _listify(self_value) + _listify(other_value)
+    elif merge_behavior == MergeBehavior.Update:
+        if not isinstance(self_value, dict):
+            raise DbtInternalError(f"expected dict, got {self_value}")
+        if not isinstance(other_value, dict):
+            raise DbtInternalError(f"expected dict, got {other_value}")
+        value = self_value.copy()
+        value.update(other_value)
+        return value
+    elif merge_behavior == MergeBehavior.DictKeyAppend:
+        if not isinstance(self_value, dict):
+            raise DbtInternalError(f"expected dict, got {self_value}")
+        if not isinstance(other_value, dict):
+            raise DbtInternalError(f"expected dict, got {other_value}")
+        new_dict = {}
+        for key in self_value.keys():
+            new_dict[key] = _listify(self_value[key])
+        for key in other_value.keys():
+            extend = False
+            new_key = key
+            # This might start with a +, to indicate we should extend the list
+            # instead of just clobbering it
+            if new_key.startswith("+"):
+                new_key = key.lstrip("+")
+                extend = True
+            if new_key in new_dict and extend:
+                # extend the list
+                value = other_value[key]
+                new_dict[new_key].extend(_listify(value))
+            else:
+                # clobber the list
+                new_dict[new_key] = _listify(other_value[key])
+        return new_dict
+
+    else:
+        raise DbtInternalError(f"Got an invalid merge_behavior: {merge_behavior}")

core/dbt/common/contracts/config/materialization.py

@@ -0,0 +1,11 @@
+from dbt.common.dataclass_schema import StrEnum
+
+
+class OnConfigurationChangeOption(StrEnum):
+    Apply = "apply"
+    Continue = "continue"
+    Fail = "fail"
+
+    @classmethod
+    def default(cls) -> "OnConfigurationChangeOption":
+        return cls.Apply

core/dbt/common/contracts/config/metadata.py

@@ -0,0 +1,69 @@
+from dataclasses import Field
+from enum import Enum
+from typing import TypeVar, Type, Optional, Dict, Any
+
+from dbt.common.exceptions import DbtInternalError
+
+M = TypeVar("M", bound="Metadata")
+
+
+class Metadata(Enum):
+    @classmethod
+    def from_field(cls: Type[M], fld: Field) -> M:
+        default = cls.default_field()
+        key = cls.metadata_key()
+
+        return _get_meta_value(cls, fld, key, default)
+
+    def meta(self, existing: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+        key = self.metadata_key()
+        return _set_meta_value(self, key, existing)
+
+    @classmethod
+    def default_field(cls) -> "Metadata":
+        raise NotImplementedError("Not implemented")
+
+    @classmethod
+    def metadata_key(cls) -> str:
+        raise NotImplementedError("Not implemented")
+
+
+def _get_meta_value(cls: Type[M], fld: Field, key: str, default: Any) -> M:
+    # a metadata field might exist. If it does, it might have a matching key.
+    # If it has both, make sure the value is valid and return it. If it
+    # doesn't, return the default.
+    if fld.metadata:
+        value = fld.metadata.get(key, default)
+    else:
+        value = default
+
+    try:
+        return cls(value)
+    except ValueError as exc:
+        raise DbtInternalError(f"Invalid {cls} value: {value}") from exc
+
+
+def _set_meta_value(obj: M, key: str, existing: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
+    if existing is None:
+        result = {}
+    else:
+        result = existing.copy()
+    result.update({key: obj})
+    return result
+
+
+class ShowBehavior(Metadata):
+    Show = 1
+    Hide = 2
+
+    @classmethod
+    def default_field(cls) -> "ShowBehavior":
+        return cls.Show
+
+    @classmethod
+    def metadata_key(cls) -> str:
+        return "show_hide"
+
+    @classmethod
+    def should_show(cls, fld: Field) -> bool:
+        return cls.from_field(fld) == cls.Show