type_helpers
============

.. py:module:: type_helpers

.. autoapi-nested-parse::

   Gather all TypeVar and TypeAlias assignments in a module.



Attributes
----------

.. autoapisummary::

   type_helpers.TypeHelper
   type_helpers.TypeHelpers
   type_helpers.Statement
   type_helpers._mod
   type_helpers._code


Classes
-------

.. autoapisummary::

   type_helpers.GatherTypeHelpers
   type_helpers.AddTypeHelpers


Functions
---------

.. autoapisummary::

   type_helpers.is_TypeAlias
   type_helpers.is_TypeVar
   type_helpers.is_CONSTANT
   type_helpers.is_AnnCONSTANT
   type_helpers.is_ParamSpec
   type_helpers.is_import
   type_helpers.is_docstr


Module Contents
---------------

.. py:type:: TypeHelper
   :canonical: Union[cst.Assign, cst.AnnAssign]


.. py:type:: TypeHelpers
   :canonical: List[TypeHelper]


.. py:type:: Statement
   :canonical: Union[cst.SimpleStatementLine, cst.BaseCompoundStatement]


.. py:data:: _mod

.. py:data:: _code

.. py:function:: is_TypeAlias(statement) -> bool

   Annotated Assign -  Foo:TypeAlias = ...


.. py:function:: is_TypeVar(statement)

   Assign - Foo = Typevar(...)


.. py:function:: is_CONSTANT(statement)

   Assign   -  FOO = ...
   AnnAssign-  FOO:bool = ...


.. py:function:: is_AnnCONSTANT(statement)

   Assign   -  FOO = ...
   AnnAssign-  FOO:bool = ...


.. py:function:: is_ParamSpec(statement)

   Assign - Foo = ParamSpec(...)


.. py:function:: is_import(statement)

   import - import foo


.. py:function:: is_docstr(statement)

   single or triple quoted string


.. py:class:: GatherTypeHelpers(context: libcst.codemod._context.CodemodContext)

   Bases: :py:obj:`libcst.codemod._visitor.ContextAwareVisitor`


   A class for tracking visited TypeVars and TypeAliases.


   .. py:attribute:: all_typehelpers
      :type:  Dict[Tuple[str, Ellipsis], TypeHelpers]


   .. py:attribute:: stack
      :type:  List[str]
      :value: []



   .. py:method:: visit_ClassDef(node: libcst.ClassDef) -> Optional[bool]

      keep track of the the (class, method) names to the stack



   .. py:method:: leave_ClassDef(original_node: libcst.ClassDef) -> None

      remove the class name from the stack



   .. py:method:: visit_Assign(node: libcst.Assign) -> None

      Find all TypeVar assignments in the module.
      format: T = TypeVar("T", int, float, str, bytes, Tuple)
      or Constants



   .. py:method:: visit_AnnAssign(node: libcst.AnnAssign) -> None

      "
      Find all TypeAlias assignments in the module.
      format: T: TypeAlias = str



.. py:class:: AddTypeHelpers(context: libcst.codemod._context.CodemodContext)

   Bases: :py:obj:`libcst.codemod._visitor.ContextAwareTransformer`


   Visitor loosly based on AddImportsVisitor


   .. py:attribute:: CONTEXT_KEY
      :value: 'AddTypeHelpers'



   .. py:attribute:: new_typehelpers
      :type:  Dict[Tuple[str, Ellipsis], TypeHelpers]


   .. py:attribute:: all_typehelpers
      :type:  Dict[Tuple[str, Ellipsis], TypeHelpers]


   .. py:attribute:: stack
      :type:  List[str]
      :value: []



   .. py:method:: add_helpers(context: libcst.codemod._context.CodemodContext, helpers: Dict[Tuple[str, Ellipsis], TypeHelpers])
      :classmethod:



   .. py:method:: skip_first(body: Sequence[libcst.BaseStatement]) -> bool
      :staticmethod:



   .. py:method:: leave_Module(original_node: libcst.Module, updated_node: libcst.Module) -> libcst.Module


   .. py:method:: update_body(body: Sequence[libcst.BaseStatement], stack_id)


   .. py:method:: visit_ClassDef(node: libcst.ClassDef) -> Optional[bool]

      keep track of the the (class, method) names to the stack



   .. py:method:: leave_ClassDef(original_node: libcst.ClassDef, updated_node: libcst.ClassDef) -> libcst.ClassDef


   .. py:method:: _split_body(body: Sequence[libcst.BaseStatement]) -> Tuple[Sequence[libcst.BaseStatement], Sequence[libcst.BaseStatement], Sequence[libcst.BaseStatement]]

      Split the module into 3 parts:
      - before any TypeAlias, TypeVar or ParamSpec statements
      - the TypeAlias and TypeVar statements
      - the rest of the module after the TypeAlias and TypeVar statements