Merge pull request #14 from wayfair-incubator/jp_custom_resources

Support Custom Resources

gator/exceptions.py

@@ -6,5 +6,5 @@ class InvalidSpecificationError(GatorError):
     """There was an error with retrieving specification data."""
 
 
-class FilterExecutionError(GatorError):
-    """There was an error executing logic for a FilterResource."""
+class InvalidResourceError(GatorError):
+    """The given custom resource definition was not valid."""

gator/resources/build.py

@@ -1,43 +1,61 @@
-from typing import Dict, Type
+from typing import Dict, List, Optional, Type
 
 import yaml
-from pydantic import ValidationError, parse_obj_as
+from pydantic import ValidationError
 
-from gator.exceptions import InvalidSpecificationError
-from gator.resources.changeset import Changeset
+from gator.exceptions import InvalidResourceError, InvalidSpecificationError
 from gator.resources.code_changes import (
     NewFileCodeChangeV1Alpha,
     RegexReplaceCodeChangeV1Alpha,
     RemoveFileCodeChangeV1Alpha,
 )
 from gator.resources.filters.regex_filter import RegexFilterV1Alpha
-from gator.resources.models import GatorResource
+from gator.resources.models import (
+    BaseModelForbidExtra,
+    CodeChangeResource,
+    FilterResource,
+    GatorResource,
+)
 
-ACTIVE_RESOURCES: Dict[str, Type[GatorResource]] = {
+ACTIVE_RESOURCES = {
     "NewFileCodeChange": NewFileCodeChangeV1Alpha,
     "RemoveFileCodeChange": RemoveFileCodeChangeV1Alpha,
     "RegexReplaceCodeChange": RegexReplaceCodeChangeV1Alpha,
     "RegexFilter": RegexFilterV1Alpha,
 }
 
 
-def build_gator_resource(resource_dict: Dict) -> GatorResource:
-    if "kind" not in resource_dict:
-        raise InvalidSpecificationError(
-            "Resources must have a 'kind' field at the top level"
-        )
+class _ResourceWithValidation(GatorResource):
+    """Define a subclass of Gator Resource that tricks"""
 
-    _class = ACTIVE_RESOURCES.get(resource_dict["kind"])
+    @classmethod
+    def __get_validators__(cls):
+        yield cls.return_kind
 
-    if not _class:
-        raise InvalidSpecificationError(
-            f"Resource kind: {resource_dict['kind']} is not active"
-        )
+    @classmethod
+    def return_kind(cls, values):
+        try:
+            kind = values["kind"]
+        except KeyError:
+            raise ValueError(f"Missing required 'kind' field for kind: {values}")
+        try:
+            return ACTIVE_RESOURCES[kind].parse_obj(values)
+        except KeyError:
+            raise ValueError(f"Incorrect kind: {kind}")
 
-    try:
-        return _class.parse_obj(resource_dict)
-    except ValidationError as e:
-        raise InvalidSpecificationError from e
+
+class ChangesetSpecV1AlphaSpec(BaseModelForbidExtra):
+    name: str
+    issue_title: Optional[str]
+    issue_body: Optional[str]
+    filters: Optional[List[_ResourceWithValidation]]
+    code_changes: Optional[List[_ResourceWithValidation]]
+
+
+class Changeset(BaseModelForbidExtra):
+    kind = "Changeset"
+    version = "v1alpha"
+    spec: ChangesetSpecV1AlphaSpec
 
 
 def build_changeset(spec: str) -> Changeset:
@@ -54,6 +72,59 @@ def build_changeset(spec: str) -> Changeset:
         raise InvalidSpecificationError from e
 
     try:
-        return parse_obj_as(Changeset, changeset_dict)
+        return Changeset.parse_obj(changeset_dict)
     except ValidationError as e:
         raise InvalidSpecificationError from e
+
+
+def build_gator_resource(resource_dict: Dict) -> GatorResource:
+    """
+    Build a Gator Resource Pydantic model from a dictionary representation.
+
+    :param resource_dict: dictionary representation of the resource to build a model for.
+    :raises InvalidSpecificationError: If the resource dict could not be built into a model.
+    :return: Fully-constructed and validated GatorResource.
+    """
+    kind = resource_dict.get("kind")
+    if not kind:
+        raise InvalidSpecificationError(
+            "Resource is not valid, must contain top-level field 'kind'"
+        )
+
+    resource_class = ACTIVE_RESOURCES.get(kind)
+    if not resource_class:
+        raise InvalidSpecificationError(f"No active resources found of kind: {kind}")
+
+    try:
+        return resource_class.parse_obj(resource_dict)
+    except ValidationError as e:
+        raise InvalidSpecificationError(
+            "Could not parse resource spec into the corresponding model"
+        ) from e
+
+
+def register_custom_resource(resource_class: Type) -> None:
+    """
+    Register a custom Gator resource.
+
+    Use this function to register a custom resource with Gator. This
+    :param resource_class: Pydantic class, extending CodeChangeResource or FilterResource,
+        that contains the business logic for executing the resource
+    """
+    global ACTIVE_RESOURCES
+
+    if not issubclass(resource_class, CodeChangeResource) or issubclass(
+        resource_class, FilterResource
+    ):
+        raise InvalidResourceError(
+            "Resource must subclass either CodeChangeResource or FilterResource"
+        )
+
+    try:
+        ACTIVE_RESOURCES[
+            resource_class.schema()["properties"]["kind"]["const"]
+        ] = resource_class
+    except KeyError:
+        raise InvalidResourceError(
+            "Custom resource must define a class variable 'kind'"
+        )

gator/resources/code_changes/new_file.py

@@ -4,11 +4,7 @@
 from typing import List
 
 from gator.constants import VERSION_V1_ALPHA
-from gator.resources.models import (
-    BaseModelForbidExtra,
-    CodeChangeResource,
-    GatorResourceSpec,
-)
+from gator.resources.models import BaseModelForbidExtra, CodeChangeResource
 
 _logger = logging.getLogger(__name__)
 
@@ -18,7 +14,7 @@ class FileDetails(BaseModelForbidExtra):
     file_content: str
 
 
-class NewFileCodeChangeV1AlphaSpec(GatorResourceSpec):
+class NewFileCodeChangeV1AlphaSpec(BaseModelForbidExtra):
     files: List[FileDetails]
 
 

gator/resources/code_changes/regex_replace.py

@@ -4,11 +4,7 @@
 from typing import List, Pattern
 
 from gator.constants import VERSION_V1_ALPHA
-from gator.resources.models import (
-    BaseModelForbidExtra,
-    CodeChangeResource,
-    GatorResourceSpec,
-)
+from gator.resources.models import BaseModelForbidExtra, CodeChangeResource
 from gator.resources.util import get_recursive_path_contents
 
 _logger = logging.getLogger(__name__)
@@ -20,7 +16,7 @@ class RegexReplacementDetails(BaseModelForbidExtra):
     replace_term: str
 
 
-class RegexReplaceCodeChangeV1AlphaSpec(GatorResourceSpec):
+class RegexReplaceCodeChangeV1AlphaSpec(BaseModelForbidExtra):
     replacement_details: List[RegexReplacementDetails]
 
 

gator/resources/code_changes/remove_file.py

@@ -4,12 +4,12 @@
 from typing import List
 
 from gator.constants import VERSION_V1_ALPHA
-from gator.resources.models import CodeChangeResource, GatorResourceSpec
+from gator.resources.models import BaseModelForbidExtra, CodeChangeResource
 
 _logger = logging.getLogger(__name__)
 
 
-class RemoveFileCodeChangeV1AlphaSpec(GatorResourceSpec):
+class RemoveFileCodeChangeV1AlphaSpec(BaseModelForbidExtra):
     files: List[str]
 
 

gator/resources/filters/regex_filter.py

@@ -4,13 +4,13 @@
 from typing import List
 
 from gator.constants import DEFAULT_REGEX_MODES
-from gator.resources.models import FilterResource, GatorResourceSpec
+from gator.resources.models import BaseModelForbidExtra, FilterResource
 from gator.resources.util import get_recursive_path_contents
 
 _logger = logging.getLogger(__name__)
 
 
-class RegexFilterV1AlphaSpec(GatorResourceSpec):
+class RegexFilterV1AlphaSpec(BaseModelForbidExtra):
     regex: str
     paths: List[str]
 

gator/resources/models.py

@@ -1,18 +1,8 @@
 from abc import abstractmethod
-from enum import Enum
 from pathlib import Path
-from typing import Any, Dict
 
 from pydantic import BaseModel
 
-from gator.constants import RESOURCE_KIND_GENERIC, RESOURCE_VERSION_UNUSABLE
-
-
-class GatorResourceType(Enum):
-    FILTER = "filter"
-    CODE_CHANGE = "code_change"
-    CHANGESET = "changeset"
-
 
 class BaseModelForbidExtra(BaseModel):
     """
@@ -23,56 +13,23 @@ class Config:
         extra = "forbid"
 
 
-class GatorResourceSpec(BaseModelForbidExtra):
-    """
-    GatorResourceSpec's will define the actual configurable fields of a resource.
-    """
-
-
-class GatorResource(BaseModelForbidExtra):
+class GatorResource(BaseModel):
     """
-    GatorResources define a specific `kind`, `version`, and associated spec fields.
+    Base class for all Gator Resources.
     """
 
-    spec: GatorResourceSpec
+    class Config:
+        fields = {"kind": dict(const=True)}
+        extra = "forbid"
 
 
 class FilterResource(GatorResource):
-
-    kind = RESOURCE_KIND_GENERIC
-    version = RESOURCE_VERSION_UNUSABLE
-
     @abstractmethod
     def matches(self, repo_path: Path) -> bool:
-        """
-        Concrete FilterResources must implement the `matches` function.
-
-        :param repo_path: The path to the directory where repository content exists
-        """
         ...
 
 
 class CodeChangeResource(GatorResource):
-
-    kind = RESOURCE_KIND_GENERIC
-    version = RESOURCE_VERSION_UNUSABLE
-
     @abstractmethod
     def make_code_changes(self, repo_path: Path) -> None:
-        """
-        Concrete CodeChangeResources must implement the `apply` function.
-
-        `make_code_changes` will apply a code change given the repository
-        :repo_path: The path to the directory where repository content exists
-        """
         ...
-
-
-class GatorResourceData(BaseModelForbidExtra):
-    """
-    Represents shape of data provided to `build_gator_resource()`.
-    """
-
-    kind: str
-    version: str
-    spec: Dict[str, Any]

testpad.py

@@ -1,10 +1,13 @@
-from gator.resources.build import build_changeset
+from gator.resources.build import build_changeset, register_custom_resource
+from pydantic import BaseModel
+from pathlib import Path
+from gator.resources.models import CodeChangeResource
 
 spec = """
 kind: Changeset
 version: v1alpha
-stuff: "stuff"
 spec:
+  name: time to do a thing
   issue_title: stuff
   issue_body: other stuff
   filters:
@@ -13,7 +16,7 @@
         spec:
           regex: '([ \t]+)bo1c2\:'
           paths:
-            - k8s.yaml
+            - "asd"
             - k8s.yml
   code_changes:
       - kind: RegexReplaceCodeChange
@@ -26,4 +29,34 @@
                 - "requirements-test.txt"
 """
 
-build_changeset(spec)
+print(build_changeset(spec))
+
+# class DoNothingSpec(BaseModel):
+#     some_value: str
+#
+# class DoNothingCodeChange(CodeChangeResource):
+#     kind = 'DoNothingCodeChange'
+#     version = 'v1alpha'
+#     spec: DoNothingSpec
+#
+#     def make_code_changes(self, path: Path) -> None:
+#         pass
+#
+# register_custom_resource(DoNothingCodeChange)
+#
+# another_spec = """
+# kind: Changeset
+# version: v1alpha
+# spec:
+#   name: time to do a thing
+#   issue_title: stuff
+#   issue_body: other stuff
+#   code_changes:
+#       - kind: DoNothingCodeChange
+#         version: v1alpha
+#         spec:
+#           some_value: "concrete value"
+#
+# """
+#
+# print(build_changeset(another_spec))