add new rule

README.md

@@ -23,6 +23,7 @@ Some rules in linter should be configurated:
 [flake8]
 scenario_params_max_count = 8  # VDR109
 allowed_to_redefine_list = page,page2  # VDR311
+is_context_assert_optional = true     # VDR400
 ```
 
 ## Rules
@@ -53,3 +54,7 @@ allowed_to_redefine_list = page,page2  # VDR311
 11. [VDR310. Some steps should not have an assertion](./flake8_vedro/rules/VDR310.md)
 12. [VDR311. Scope variables should not be redefined](./flake8_vedro/rules/VDR311.md)
 13. [VDR312. Scope variables should not be partially redefined](./flake8_vedro/rules/VDR312.md)
+
+
+###  Contexts Rules
+14. [VDR400. Contexts should have specific assertions](./flake8_vedro/rules/VDR400md)

flake8_vedro/abstract_checkers/__init__.py

@@ -1,3 +1,4 @@
+from .context_checker import ContextChecker
 from .scenario_checker import ScenarioChecker
 from .scenario_helper import ScenarioHelper
 from .step_checker import StepsChecker

flake8_vedro/abstract_checkers/context_checker.py

@@ -0,0 +1,11 @@
+from abc import ABC, abstractmethod
+from typing import List
+
+from flake8_plugin_utils import Error
+
+
+class ContextChecker(ABC):
+
+    @abstractmethod
+    def check_context(self, context, config) -> List[Error]:
+        pass

flake8_vedro/config.py

@@ -2,18 +2,22 @@
 
 
 class Config:
-    def __init__(self, max_params_count: int,
+    def __init__(self, is_context_assert_optional: bool,
+                 max_params_count: int,
                  allowed_to_redefine_list: Optional[List]):
+        self.is_context_assert_optional = is_context_assert_optional
         self.max_params_count = max_params_count
         self.allowed_to_redefine_list = allowed_to_redefine_list if allowed_to_redefine_list else []
 
 
 class DefaultConfig(Config):
     def __init__(self,
+                 is_context_assert_optional: bool = True,
                  max_params_count: int = 1,
                  allowed_to_redefine_list: Optional[List] = None
                  ):
         super().__init__(
+            is_context_assert_optional=is_context_assert_optional,
             max_params_count=max_params_count,
             allowed_to_redefine_list=allowed_to_redefine_list
         )

flake8_vedro/errors/__init__.py

@@ -1,5 +1,6 @@
 from .errors import (
     ContextCallInParams,
+    ContextWithoutAssert,
     DecoratorVedroOnly,
     ExceedMaxParamsCount,
     ImportedInterfaceInWrongStep,

flake8_vedro/errors/errors.py

@@ -119,3 +119,8 @@ class ScopeVarIsRedefined(Error):
 class ScopeVarIsPartiallyRedefined(Error):
     code = 'VDR312'
     message = 'scope variable "{name}" is partially redefined'
+
+
+class ContextWithoutAssert(Error):
+    code = 'VDR400'
+    message = 'context "{context_name}" does not have an assert'

flake8_vedro/plugins.py

@@ -5,7 +5,7 @@
 from flake8.options.manager import OptionManager
 from flake8_plugin_utils import Plugin, Visitor
 
-from flake8_vedro.visitors import ScenarioVisitor
+from flake8_vedro.visitors import ContextVisitor, ScenarioVisitor
 
 from .config import Config
 from .defaults import Defaults
@@ -36,16 +36,24 @@ def _create_visitor(cls, visitor_cls: Callable, filename: Optional[str] = None)
 
 class VedroScenarioStylePlugin(PluginWithFilename):
     name = 'flake8_vedro'
-    version = '1.0.1'
+    version = '1.0.2'
     visitors = [
         ScenarioVisitor,
+        ContextVisitor
     ]
 
     def __init__(self, tree: ast.AST, filename: str, *args, **kwargs):
         super().__init__(tree, filename)
 
     @classmethod
     def add_options(cls, option_manager: OptionManager):
+        option_manager.add_option(
+            '--is-context-assert-optional',
+            default='true',
+            type=str,
+            parse_from_config=True,
+            help='If contexts should have specific assertions',
+        )
         option_manager.add_option(
             '--scenario-params-max-count',
             default=Defaults.MAX_PARAMS_COUNT,
@@ -66,6 +74,7 @@ def parse_options_to_config(
         cls, option_manager: OptionManager, options: argparse.Namespace, args: List[str]
     ) -> Config:
         return Config(
+            is_context_assert_optional=str_to_bool(options.is_context_assert_optional),
             max_params_count=options.scenario_params_max_count,
             allowed_to_redefine_list=options.allowed_to_redefine_list,
         )

flake8_vedro/rules/VDR400md

@@ -0,0 +1,25 @@
+# VDR400. contexts should have an assertion
+The Vedro framework Сontexts should contain an assertion. This ensures that the application state has changed
+### ❌ Anti-pattern
+```python
+# ./contexts/registered_user.py
+import vedro
+from interfaces.chat_api import ChatApi
+
+@vedro.context
+def registered_user(user):
+    response = ChatApi().register(user) # <- no assert
+
+```
+### ✅Best practice
+```python
+# ./contexts/registered_user.py
+import vedro
+from interfaces.chat_api import ChatApi
+
+@vedro.context
+def registered_user(user):
+    response = ChatApi().register(user)
+    assert response.status_code == 200
+```
+

flake8_vedro/types/__init__.py

@@ -1 +1 @@
-from .types import StepType
+from .types import FuncType

flake8_vedro/types/types.py

@@ -1,4 +1,4 @@
 import ast
 from typing import Union
 
-StepType = Union[ast.FunctionDef, ast.AsyncFunctionDef]
+FuncType = Union[ast.FunctionDef, ast.AsyncFunctionDef]

flake8_vedro/visitors/__init__.py

@@ -1,3 +1,5 @@
+from .context_checkers import ContextAssertChecker
+from .context_visitor import ContextVisitor
 from .scenario_checkers import (
     LocationChecker,
     ParametrizationCallChecker,

flake8_vedro/visitors/context_checkers/__init__.py

@@ -0,0 +1 @@
+from .assert_checker import ContextAssertChecker

flake8_vedro/visitors/context_checkers/assert_checker.py

@@ -0,0 +1,31 @@
+import ast
+from typing import List
+
+from flake8_plugin_utils import Error
+
+from flake8_vedro.abstract_checkers import ContextChecker
+from flake8_vedro.errors import ContextWithoutAssert
+from flake8_vedro.visitors.context_visitor import Context, ContextVisitor
+
+
+@ContextVisitor.register_context_checker
+class ContextAssertChecker(ContextChecker):
+
+    def check_context(self, context: Context, config) -> List[Error]:
+        errors = []
+        has_assert = self._has_assert_in_block(context.node.body)
+
+        if not has_assert:
+            errors.append(ContextWithoutAssert(context.node.lineno, context.node.col_offset,
+                                               context_name=context.node.name))
+
+        return errors
+
+    def _has_assert_in_block(self, block: List[ast.stmt]) -> bool:
+        for line in block:
+            if isinstance(line, ast.Assert):
+                return True
+            elif isinstance(line, (ast.With, ast.AsyncWith)):
+                if self._has_assert_in_block(line.body):
+                    return True
+        return False

flake8_vedro/visitors/context_visitor.py

@@ -0,0 +1,61 @@
+import ast
+from typing import List, Optional, Type, Union
+
+from flake8_plugin_utils import Error
+
+from flake8_vedro.abstract_checkers import ContextChecker
+from flake8_vedro.config import Config
+from flake8_vedro.types import FuncType
+from flake8_vedro.visitors._visitor_with_filename import VisitorWithFilename
+
+
+class Context:
+    def __init__(self, node: List[FuncType], filename: str):
+        self.node = node
+        self.filename = filename
+
+
+class ContextVisitor(VisitorWithFilename):
+    context_checkers: List[ContextChecker] = []
+
+    def __init__(self, config: Optional[Config] = None,
+                 filename: Optional[str] = None) -> None:
+        super().__init__(config, filename)
+
+    @property
+    def config(self):
+        return self._config
+
+    @classmethod
+    def register_context_checker(cls, checker: Type[ContextChecker]):
+        cls.context_checkers.append(checker())
+        return checker
+
+    @classmethod
+    def deregister_all(cls):
+        cls.context_checkers = []
+
+    def _check_context_decorator(self, node: Union[ast.FunctionDef, ast.AsyncFunctionDef]):
+        if self.config.is_context_assert_optional:
+            return []
+
+        for decorator in node.decorator_list:
+            if (isinstance(decorator, ast.Attribute)
+                    and decorator.value.id == 'vedro'
+                    and decorator.attr == 'context'):
+                context = Context(node=node,
+                                  filename=self.filename)
+                try:
+                    for checker in self.context_checkers:
+                        self.errors.extend(checker.check_context(context, self.config))
+                except Exception as e:
+                    print(f'Linter failed: checking {context.filename} with {checker.__class__}.\n'
+                          f'Exception: {e}')
+
+    def visit_FunctionDef(self, node: ast.FunctionDef) -> List[Error]:
+        self._check_context_decorator(node)
+        return []
+
+    def visit_AsyncFunctionDef(self, node: ast.AsyncFunctionDef) -> List[Error]:
+        self._check_context_decorator(node)
+        return []

flake8_vedro/visitors/scenario_visitor.py

@@ -7,12 +7,12 @@
     StepsChecker
 )
 from flake8_vedro.config import Config
-from flake8_vedro.types import StepType
+from flake8_vedro.types import FuncType
 from flake8_vedro.visitors._visitor_with_filename import VisitorWithFilename
 
 
 class Context:
-    def __init__(self, steps: List[StepType], scenario_node: ast.ClassDef,
+    def __init__(self, steps: List[FuncType], scenario_node: ast.ClassDef,
                  import_from_nodes: List[ast.ImportFrom],
                  filename: str):
         self.steps = steps

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = flake8_vedro
-version = 1.0.1
+version = 1.0.2
 
 [options.entry_points]
 flake8.extension =
@@ -16,6 +16,7 @@ ignore = W503
 
 # flake8-vedro params
 scenario_params_max_count = 8
+is_context_assert_optional = true
 
 
 [mypy]

setup.py

@@ -15,14 +15,14 @@ def find_dev_required():
 
 setup(
     name="flake8-vedro",
-    version="1.0.1",
+    version="1.0.2",
     description="flake8 based linter for vedro framework",
     long_description=open("README.md").read(),
     long_description_content_type="text/markdown",
     python_requires=">=3.10",
     url="https://github.com/mytestopia/flake8-vedro",
     author="Anna",
-    author_email="[email protected]",    
+    author_email="[email protected]",
     license="Apache-2.0",
     packages=find_packages(exclude=("tests",)),
     package_data={"flake8_vedro": ["py.typed"]},