Added validators for users and recipes (#1052)

* Added validators for users and recipes

provide a simple get api, allowing to test for existence of
- user by username
- recipe by slug
- group by name (not tested yet)

* updated formatting

* Use group_id+slug for recipes, use ValidationRespone

* Fixed Flake8 errors and warnings

* add missing field for TestUser init

mealie/routes/validators/__init__.py

@@ -0,0 +1,9 @@
+from fastapi import APIRouter
+
+from . import validators
+
+prefix = "/validators"
+
+router = APIRouter()
+
+router.include_router(validators.router, prefix=prefix, tags=["Validators"])

mealie/routes/validators/validators.py

@@ -0,0 +1,34 @@
+from uuid import UUID
+
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm.session import Session
+
+from mealie.db.db_setup import generate_session
+from mealie.repos.all_repositories import get_repositories
+from mealie.schema.response import ValidationResponse
+
+router = APIRouter()
+
+
+@router.get("/user/{name}", response_model=ValidationResponse)
+def validate_user(name: str, session: Session = Depends(generate_session)):
+    """Checks if a user with the given name exists"""
+    db = get_repositories(session)
+    existing_element = db.users.get_by_username(name)
+    return ValidationResponse(valid=existing_element is None)
+
+
+@router.get("/group/{name}", response_model=ValidationResponse)
+def validate_group(name: str, session: Session = Depends(generate_session)):
+    """Checks if a group with the given name exists"""
+    db = get_repositories(session)
+    existing_element = db.groups.get_by_name(name)
+    return ValidationResponse(valid=existing_element is None)
+
+
+@router.get("/recipe/{group_id}/{slug}", response_model=ValidationResponse)
+def validate_recipe(group_id: UUID, slug: str, session: Session = Depends(generate_session)):
+    """Checks if a group with the given slug exists"""
+    db = get_repositories(session)
+    existing_element = db.recipes.get_by_slug(group_id, slug)
+    return ValidationResponse(valid=existing_element is None)