Validate component usage (#23037)

* Update manifest validator

* Update circle

* Update text

* Typo

* fix link to codeowners

* Merge CODEOWNERS into hassfest

* Annotate errors with fixable

* Convert error to warning

* Lint

* Make abs path

* Python 3.5...

* Typo

* Fix tests

script/hassfest/model.py

@@ -0,0 +1,91 @@
+"""Models for manifest validator."""
+import json
+from typing import List, Dict, Any
+import pathlib
+
+import attr
+
+
+@attr.s
+class Error:
+    """Error validating an integration."""
+
+    plugin = attr.ib(type=str)
+    error = attr.ib(type=str)
+    fixable = attr.ib(type=bool, default=False)
+
+    def __str__(self) -> str:
+        """Represent error as string."""
+        return "[{}] {}".format(self.plugin.upper(), self.error)
+
+
+@attr.s
+class Config:
+    """Config for the run."""
+
+    root = attr.ib(type=pathlib.Path)
+    action = attr.ib(type=str)
+    errors = attr.ib(type=List[Error], factory=list)
+    cache = attr.ib(type=Dict[str, Any], factory=dict)
+
+    def add_error(self, *args, **kwargs):
+        """Add an error."""
+        self.errors.append(Error(*args, **kwargs))
+
+
+@attr.s
+class Integration:
+    """Represent an integration in our validator."""
+
+    @classmethod
+    def load_dir(cls, path: pathlib.Path):
+        """Load all integrations in a directory."""
+        assert path.is_dir()
+        integrations = {}
+        for fil in path.iterdir():
+            if fil.is_file() or fil.name == '__pycache__':
+                continue
+
+            integration = cls(fil)
+            integration.load_manifest()
+            integrations[integration.domain] = integration
+
+        return integrations
+
+    path = attr.ib(type=pathlib.Path)
+    manifest = attr.ib(type=dict, default=None)
+    errors = attr.ib(type=List[Error], factory=list)
+
+    @property
+    def domain(self) -> str:
+        """Integration domain."""
+        return self.path.name
+
+    @property
+    def manifest_path(self) -> pathlib.Path:
+        """Integration manifest path."""
+        return self.path / 'manifest.json'
+
+    def add_error(self, *args, **kwargs):
+        """Add an error."""
+        self.errors.append(Error(*args, **kwargs))
+
+    def load_manifest(self) -> None:
+        """Load manifest."""
+        if not self.manifest_path.is_file():
+            self.add_error(
+                'model',
+                "Manifest file {} not found".format(self.manifest_path)
+            )
+            return
+
+        try:
+            manifest = json.loads(self.manifest_path.read_text())
+        except ValueError as err:
+            self.add_error(
+                'model',
+                "Manifest contains invalid JSON: {}".format(err)
+            )
+            return
+
+        self.manifest = manifest