tools: Add python types hints

tools/ci/mypy_ignore_list.txt

@@ -211,15 +211,7 @@ tools/find_apps.py
 tools/find_build_apps/common.py
 tools/gen_esp_err_to_name.py
 tools/gen_soc_caps_kconfig/test/test_gen_soc_caps_kconfig.py
-tools/idf.py
-tools/idf_py_actions/core_ext.py
-tools/idf_py_actions/create_ext.py
-tools/idf_py_actions/debug_ext.py
-tools/idf_py_actions/dfu_ext.py
-tools/idf_py_actions/errors.py
-tools/idf_py_actions/serial_ext.py
 tools/idf_py_actions/tools.py
-tools/idf_py_actions/uf2_ext.py
 tools/kconfig_new/confgen.py
 tools/kconfig_new/confserver.py
 tools/kconfig_new/gen_kconfig_doc.py
@@ -240,7 +232,6 @@ tools/ldgen/test/test_fragments.py
 tools/ldgen/test/test_generation.py
 tools/ldgen/test/test_output_commands.py
 tools/mass_mfg/mfg_gen.py
-tools/mkuf2.py
 tools/test_apps/build_system/ldgen_test/check_placements.py
 tools/test_apps/protocols/mqtt/publish_connect_test/app_test.py
 tools/test_apps/protocols/openssl/app_test.py

tools/gen_esp_err_to_name.py

@@ -6,6 +6,7 @@
 from __future__ import print_function, unicode_literals
 
 import sys
+from typing import Any, List, Optional, TextIO
 
 try:
     from builtins import object, range, str
@@ -57,7 +58,7 @@ class ErrItem(object):
     - rel_str - (optional) error string which is a base for the error
     - rel_off - (optional) offset in relation to the base error
     """
-    def __init__(self, name, file, include_as=None, comment='', rel_str='', rel_off=0):
+    def __init__(self, name: str, file: str, include_as: Optional[Any]=None, comment: str='', rel_str: str='', rel_off: int=0) -> None:
         self.name = name
         self.file = file
         self.include_as = include_as
@@ -65,7 +66,7 @@ class ErrItem(object):
         self.rel_str = rel_str
         self.rel_off = rel_off
 
-    def __str__(self):
+    def __str__(self) -> str:
         ret = self.name + ' from ' + self.file
         if (self.rel_str != ''):
             ret += ' is (' + self.rel_str + ' + ' + str(self.rel_off) + ')'
@@ -73,7 +74,7 @@ class ErrItem(object):
             ret += ' // ' + self.comment
         return ret
 
-    def __cmp__(self, other):
+    def __cmp__(self, other) -> int:
         if self.file in priority_headers and other.file not in priority_headers:
             return -1
         elif self.file not in priority_headers and other.file in priority_headers:
@@ -101,11 +102,11 @@ class InputError(RuntimeError):
     """
     Represents and error on the input
     """
-    def __init__(self, p, e):
+    def __init__(self, p: str, e: str) -> None:
         super(InputError, self).__init__(p + ': ' + e)
 
 
-def process(line, idf_path, include_as):
+def process(line: str, idf_path: str, include_as: Any) -> None:
     """
     Process a line of text from file idf_path (relative to IDF project).
     Fills the global list unproc_list and dictionaries err_dict, rev_err_dict
@@ -168,7 +169,7 @@ def process(line, idf_path, include_as):
         unproc_list.append(ErrItem(words[1], idf_path, include_as, comment, related, num))
 
 
-def process_remaining_errors():
+def process_remaining_errors() -> None:
     """
     Create errors which could not be processed before because the error code
     for the BASE error code wasn't known.
@@ -189,7 +190,7 @@ def process_remaining_errors():
     del unproc_list[:]
 
 
-def path_to_include(path):
+def path_to_include(path: str) -> str:
     """
     Process the path (relative to the IDF project) in a form which can be used
     to include in a C file. Using just the filename does not work all the
@@ -210,7 +211,7 @@ def path_to_include(path):
         return os.sep.join(spl_path[i + 1:])  # subdirectories and filename in "include"
 
 
-def print_warning(error_list, error_code):
+def print_warning(error_list: List, error_code: int) -> None:
     """
     Print warning about errors with the same error code
     """
@@ -219,7 +220,7 @@ def print_warning(error_list, error_code):
         print('    ' + str(e))
 
 
-def max_string_width():
+def max_string_width() -> int:
     max = 0
     for k in err_dict:
         for e in err_dict[k]:
@@ -229,7 +230,7 @@ def max_string_width():
     return max
 
 
-def generate_c_output(fin, fout):
+def generate_c_output(fin: TextIO, fout: TextIO) -> None:
     """
     Writes the output to fout based on th error dictionary err_dict and
     template file fin.
@@ -294,7 +295,7 @@ def generate_c_output(fin, fout):
             fout.write(line)
 
 
-def generate_rst_output(fout):
+def generate_rst_output(fout: TextIO) -> None:
     for k in sorted(err_dict.keys()):
         v = err_dict[k][0]
         fout.write(':c:macro:`{}` '.format(v.name))
@@ -307,7 +308,7 @@ def generate_rst_output(fout):
         fout.write('\n\n')
 
 
-def main():
+def main() -> None:
     if 'IDF_PATH' in os.environ:
         idf_path = os.environ['IDF_PATH']
     else:

tools/idf.py

@@ -13,7 +13,7 @@
 # check_environment() function below. If possible, avoid importing
 # any external libraries here - put in external script, or import in
 # their specific function instead.
-from __future__ import print_function
+from __future__ import annotations
 
 import codecs
 import json
@@ -23,9 +23,11 @@ import os.path
 import signal
 import subprocess
 import sys
-from collections import Counter, OrderedDict
+from collections import Counter, OrderedDict, _OrderedDictKeysView
 from importlib import import_module
 from pkgutil import iter_modules
+from types import FrameType
+from typing import Any, Callable, Dict, List, Optional, TextIO, Union
 
 # pyc files remain in the filesystem when switching between branches which might raise errors for incompatible
 # idf.py extensions. Therefore, pyc file generation is turned off:
@@ -35,7 +37,8 @@ import python_version_checker  # noqa: E402
 
 try:
     from idf_py_actions.errors import FatalError  # noqa: E402
-    from idf_py_actions.tools import executable_exists, idf_version, merge_action_lists, realpath  # noqa: E402
+    from idf_py_actions.tools import (PropertyDict, executable_exists, idf_version, merge_action_lists,  # noqa: E402
+                                      realpath)
 except ImportError:
     # For example, importing click could cause this.
     print('Please use idf.py only in an ESP-IDF shell environment.', file=sys.stderr)
@@ -61,12 +64,12 @@ SHELL_COMPLETE_RUN = SHELL_COMPLETE_VAR in os.environ
 
 # function prints warning when autocompletion is not being performed
 # set argument stream to sys.stderr for errors and exceptions
-def print_warning(message, stream=None):
+def print_warning(message: str, stream: TextIO=None) -> None:
     if not SHELL_COMPLETE_RUN:
         print(message, file=stream or sys.stderr)
 
 
-def check_environment():
+def check_environment() -> List:
     """
     Verify the environment contains the top-level tools we need to operate
 
@@ -121,7 +124,7 @@ def check_environment():
     return checks_output
 
 
-def _safe_relpath(path, start=None):
+def _safe_relpath(path: str, start: Optional[str]=None) -> str:
     """ Return a relative path, same as os.path.relpath, but only if this is possible.
 
     It is not possible on Windows, if the start directory and the path are on different drives.
@@ -132,7 +135,7 @@ def _safe_relpath(path, start=None):
         return os.path.abspath(path)
 
 
-def debug_print_idf_version():
+def debug_print_idf_version() -> None:
     version = idf_version()
     if version:
         print_warning('ESP-IDF %s' % version)
@@ -140,30 +143,13 @@ def debug_print_idf_version():
         print_warning('ESP-IDF version unknown')
 
 
-class PropertyDict(dict):
-    def __getattr__(self, name):
-        if name in self:
-            return self[name]
-        else:
-            raise AttributeError("'PropertyDict' object has no attribute '%s'" % name)
-
-    def __setattr__(self, name, value):
-        self[name] = value
-
-    def __delattr__(self, name):
-        if name in self:
-            del self[name]
-        else:
-            raise AttributeError("'PropertyDict' object has no attribute '%s'" % name)
-
-
-def init_cli(verbose_output=None):
+def init_cli(verbose_output: List=None) -> Any:
     # Click is imported here to run it after check_environment()
     import click
 
     class Deprecation(object):
         """Construct deprecation notice for help messages"""
-        def __init__(self, deprecated=False):
+        def __init__(self, deprecated: Union[Dict, str, bool]=False) -> None:
             self.deprecated = deprecated
             self.since = None
             self.removed = None
@@ -178,7 +164,7 @@ def init_cli(verbose_output=None):
             elif isinstance(deprecated, str):
                 self.custom_message = deprecated
 
-        def full_message(self, type='Option'):
+        def full_message(self, type: str='Option') -> str:
             if self.exit_with_error:
                 return '%s is deprecated %sand was removed%s.%s' % (
                     type,
@@ -194,15 +180,15 @@ def init_cli(verbose_output=None):
                     ' %s' % self.custom_message if self.custom_message else '',
                 )
 
-        def help(self, text, type='Option', separator=' '):
+        def help(self, text: str, type: str='Option', separator: str=' ') -> str:
             text = text or ''
             return self.full_message(type) + separator + text if self.deprecated else text
 
-        def short_help(self, text):
+        def short_help(self, text: str) -> str:
             text = text or ''
             return ('Deprecated! ' + text) if self.deprecated else text
 
-    def check_deprecation(ctx):
+    def check_deprecation(ctx: click.core.Context) -> None:
         """Prints deprecation warnings for arguments in given context"""
         for option in ctx.command.params:
             default = () if option.multiple else option.default
@@ -214,7 +200,8 @@ def init_cli(verbose_output=None):
                     print_warning('Warning: %s' % deprecation.full_message('Option "%s"' % option.name))
 
     class Task(object):
-        def __init__(self, callback, name, aliases, dependencies, order_dependencies, action_args):
+        def __init__(self, callback: Callable, name: str, aliases: List, dependencies: Optional[List],
+                     order_dependencies: Optional[List], action_args: Dict) -> None:
             self.callback = callback
             self.name = name
             self.dependencies = dependencies
@@ -222,7 +209,7 @@ def init_cli(verbose_output=None):
             self.action_args = action_args
             self.aliases = aliases
 
-        def __call__(self, context, global_args, action_args=None):
+        def __call__(self, context: click.core.Context, global_args: PropertyDict, action_args: Dict=None) -> None:
             if action_args is None:
                 action_args = self.action_args
 
@@ -231,26 +218,24 @@ def init_cli(verbose_output=None):
     class Action(click.Command):
         def __init__(
                 self,
-                name=None,
-                aliases=None,
-                deprecated=False,
-                dependencies=None,
-                order_dependencies=None,
-                hidden=False,
-                **kwargs):
+                name: Optional[str]=None,
+                aliases: Optional[List]=None,
+                deprecated: Union[Dict, str, bool]=False,
+                dependencies: Optional[List]=None,
+                order_dependencies: Optional[List]=None,
+                hidden: bool=False,
+                **kwargs: Any) -> None:
             super(Action, self).__init__(name, **kwargs)
 
-            self.name = self.name or self.callback.__name__
-            self.deprecated = deprecated
-            self.hidden = hidden
+            self.name: str = self.name or self.callback.__name__
+            self.deprecated: Union[Dict, str, bool] = deprecated
+            self.hidden: bool = hidden
 
             if aliases is None:
                 aliases = []
             self.aliases = aliases
 
-            self.help = self.help or self.callback.__doc__
-            if self.help is None:
-                self.help = ''
+            self.help: str = self.help or self.callback.__doc__ or ''
 
             if dependencies is None:
                 dependencies = []
@@ -259,7 +244,7 @@ def init_cli(verbose_output=None):
                 order_dependencies = []
 
             # Show first line of help if short help is missing
-            self.short_help = self.short_help or self.help.split('\n')[0]
+            self.short_help: str = self.short_help or self.help.split('\n')[0]
 
             if deprecated:
                 deprecation = Deprecation(deprecated)
@@ -276,7 +261,7 @@ def init_cli(verbose_output=None):
             self.unwrapped_callback = self.callback
             if self.callback is not None:
 
-                def wrapped_callback(**action_args):
+                def wrapped_callback(**action_args: Any) -> Task:
                     return Task(
                         callback=self.unwrapped_callback,
                         name=self.name,
@@ -288,7 +273,7 @@ def init_cli(verbose_output=None):
 
                 self.callback = wrapped_callback
 
-        def invoke(self, ctx):
+        def invoke(self, ctx: click.core.Context) -> click.core.Context:
             if self.deprecated:
                 deprecation = Deprecation(self.deprecated)
                 message = deprecation.full_message('Command "%s"' % self.name)
@@ -310,7 +295,7 @@ def init_cli(verbose_output=None):
 
         names - alias of 'param_decls'
         """
-        def __init__(self, **kwargs):
+        def __init__(self, **kwargs: str):
             names = kwargs.pop('names')
             super(Argument, self).__init__(names, **kwargs)
 
@@ -325,7 +310,7 @@ def init_cli(verbose_output=None):
 
         SCOPES = ('default', 'global', 'shared')
 
-        def __init__(self, scope=None):
+        def __init__(self, scope: Union['Scope', str]=None) -> None:
             if scope is None:
                 self._scope = 'default'
             elif isinstance(scope, str) and scope in self.SCOPES:
@@ -336,19 +321,19 @@ def init_cli(verbose_output=None):
                 raise FatalError('Unknown scope for option: %s' % scope)
 
         @property
-        def is_global(self):
+        def is_global(self) -> bool:
             return self._scope == 'global'
 
         @property
-        def is_shared(self):
+        def is_shared(self) -> bool:
             return self._scope == 'shared'
 
-        def __str__(self):
+        def __str__(self) -> str:
             return self._scope
 
     class Option(click.Option):
         """Option that knows whether it should be global"""
-        def __init__(self, scope=None, deprecated=False, hidden=False, **kwargs):
+        def __init__(self, scope: Union[Scope, str]=None, deprecated: Union[Dict, str, bool]=False, hidden: bool=False, **kwargs: str) -> None:
             """
             Keyword arguments additional to Click's Option class:
 
@@ -369,7 +354,7 @@ def init_cli(verbose_output=None):
 
             if deprecated:
                 deprecation = Deprecation(deprecated)
-                self.help = deprecation.help(self.help)
+                self.help: str = deprecation.help(self.help)
 
             if self.envvar:
                 self.help += ' The default value can be set with the %s environment variable.' % self.envvar
@@ -377,16 +362,16 @@ def init_cli(verbose_output=None):
             if self.scope.is_global:
                 self.help += ' This option can be used at most once either globally, or for one subcommand.'
 
-        def get_help_record(self, ctx):
+        def get_help_record(self, ctx: click.core.Context) -> Any:
             # Backport "hidden" parameter to click 5.0
             if self.hidden:
-                return
+                return None
 
             return super(Option, self).get_help_record(ctx)
 
     class CLI(click.MultiCommand):
         """Action list contains all actions with options available for CLI"""
-        def __init__(self, all_actions=None, verbose_output=None, help=None):
+        def __init__(self, all_actions: Dict=None, verbose_output: List=None, help: str=None) -> None:
             super(CLI, self).__init__(
                 chain=True,
                 invoke_without_command=True,
@@ -455,18 +440,21 @@ def init_cli(verbose_output=None):
 
                     self._actions[name].params.append(option)
 
-        def list_commands(self, ctx):
+        def list_commands(self, ctx: click.core.Context) -> List:
             return sorted(filter(lambda name: not self._actions[name].hidden, self._actions))
 
-        def get_command(self, ctx, name):
+        def get_command(self, ctx: click.core.Context, name: str) -> Optional[Action]:
             if name in self.commands_with_aliases:
                 return self._actions.get(self.commands_with_aliases.get(name))
 
             # Trying fallback to build target (from "all" action) if command is not known
             else:
-                return Action(name=name, callback=self._actions.get('fallback').unwrapped_callback)
+                callback = self._actions.get('fallback')
+                if callback:
+                    return Action(name=name, callback=callback.unwrapped_callback)
+                return None
 
-        def _print_closing_message(self, args, actions):
+        def _print_closing_message(self, args: PropertyDict, actions: _OrderedDictKeysView) -> None:
             # print a closing message of some kind
             #
             if any(t in str(actions) for t in ('flash', 'dfu', 'uf2', 'uf2-app')):
@@ -479,11 +467,13 @@ def init_cli(verbose_output=None):
 
             # Otherwise, if we built any binaries print a message about
             # how to flash them
-            def print_flashing_message(title, key):
-                with open(os.path.join(args.build_dir, 'flasher_args.json')) as f:
-                    flasher_args = json.load(f)
+            def print_flashing_message(title: str, key: str) -> None:
+                with open(os.path.join(args.build_dir, 'flasher_args.json')) as file:
+                    flasher_args: Dict[str, Any] = json.load(file)
 
-                def flasher_path(f):
+                def flasher_path(f: Union[str, os.PathLike[str]]) -> str:
+                    if type(args.build_dir) is bytes:
+                        args.build_dir = args.build_dir.decode()
                     return _safe_relpath(os.path.join(args.build_dir, f))
 
                 if key != 'project':  # flashing a single item
@@ -536,11 +526,11 @@ def init_cli(verbose_output=None):
                 if 'bootloader' in actions:
                     print_flashing_message('Bootloader', 'bootloader')
 
-        def execute_tasks(self, tasks, **kwargs):
+        def execute_tasks(self, tasks: List, **kwargs: str) -> OrderedDict:
             ctx = click.get_current_context()
             global_args = PropertyDict(kwargs)
 
-            def _help_and_exit():
+            def _help_and_exit() -> None:
                 print(ctx.get_help())
                 ctx.exit()
 
@@ -592,7 +582,7 @@ def init_cli(verbose_output=None):
                 _help_and_exit()
 
             # Build full list of tasks to and deal with dependencies and order dependencies
-            tasks_to_run = OrderedDict()
+            tasks_to_run: OrderedDict = OrderedDict()
             while tasks:
                 task = tasks[0]
                 tasks_dict = dict([(t.name, t) for t in tasks])
@@ -661,13 +651,13 @@ def init_cli(verbose_output=None):
         },
     )
     @click.option('-C', '--project-dir', default=os.getcwd(), type=click.Path())
-    def parse_project_dir(project_dir):
+    def parse_project_dir(project_dir: str) -> Any:
         return realpath(project_dir)
 
     # Set `complete_var` to not existing environment variable name to prevent early cmd completion
     project_dir = parse_project_dir(standalone_mode=False, complete_var='_IDF.PY_COMPLETE_NOT_EXISTING')
 
-    all_actions = {}
+    all_actions: Dict = {}
     # Load extensions from components dir
     idf_py_extensions_path = os.path.join(os.environ['IDF_PATH'], 'tools', 'idf_py_actions')
     extension_dirs = [realpath(idf_py_extensions_path)]
@@ -730,12 +720,12 @@ def init_cli(verbose_output=None):
     return CLI(help=cli_help, verbose_output=verbose_output, all_actions=all_actions)
 
 
-def signal_handler(_signal, _frame):
+def signal_handler(_signal: int, _frame: Optional[FrameType]) -> None:
     # The Ctrl+C processed by other threads inside
     pass
 
 
-def main():
+def main() -> None:
     # Processing of Ctrl+C event for all threads made by main()
     signal.signal(signal.SIGINT, signal_handler)
 
@@ -753,7 +743,7 @@ def main():
         cli(sys.argv[1:], prog_name=PROG, complete_var=SHELL_COMPLETE_VAR)
 
 
-def _valid_unicode_config():
+def _valid_unicode_config() -> Union[codecs.CodecInfo, bool]:
     # Python 2 is always good
     if sys.version_info[0] == 2:
         return True
@@ -765,15 +755,13 @@ def _valid_unicode_config():
         return False
 
 
-def _find_usable_locale():
+def _find_usable_locale() -> str:
     try:
-        locales = subprocess.Popen(['locale', '-a'], stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()[0]
+        locales = subprocess.Popen(['locale', '-a'], stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()[0].decode('ascii', 'replace')
     except OSError:
         locales = ''
-    if isinstance(locales, bytes):
-        locales = locales.decode('ascii', 'replace')
 
-    usable_locales = []
+    usable_locales: List[str] = []
     for line in locales.splitlines():
         locale = line.strip()
         locale_name = locale.lower().replace('-', '')

tools/idf_py_actions/core_ext.py

@@ -7,20 +7,22 @@ import re
 import shutil
 import subprocess
 import sys
+from typing import Any, Dict, List, Optional
 from urllib.error import URLError
 from urllib.request import Request, urlopen
 from webbrowser import open_new_tab
 
 import click
+from click.core import Context
 from idf_py_actions.constants import GENERATORS, PREVIEW_TARGETS, SUPPORTED_TARGETS, URL_TO_DOC
 from idf_py_actions.errors import FatalError
 from idf_py_actions.global_options import global_options
-from idf_py_actions.tools import (TargetChoice, ensure_build_directory, get_target, idf_version, merge_action_lists,
-                                  realpath, run_target)
+from idf_py_actions.tools import (PropertyDict, TargetChoice, ensure_build_directory, get_target, idf_version,
+                                  merge_action_lists, realpath, run_target)
 
 
-def action_extensions(base_actions, project_path):
-    def build_target(target_name, ctx, args):
+def action_extensions(base_actions: Dict, project_path: str) -> Any:
+    def build_target(target_name: str, ctx: Context, args: PropertyDict) -> None:
         """
         Execute the target build system to build target 'target_name'
 
@@ -30,7 +32,7 @@ def action_extensions(base_actions, project_path):
         ensure_build_directory(args, ctx.info_name)
         run_target(target_name, args)
 
-    def size_target(target_name, ctx, args):
+    def size_target(target_name: str, ctx: Context, args: PropertyDict) -> None:
         """
         Builds the app and then executes a size-related target passed in 'target_name'.
         `tool_error_handler` handler is used to suppress errors during the build,
@@ -38,18 +40,18 @@ def action_extensions(base_actions, project_path):
 
         """
 
-        def tool_error_handler(e):
+        def tool_error_handler(e: int) -> None:
             pass
 
         ensure_build_directory(args, ctx.info_name)
         run_target('all', args, custom_error_handler=tool_error_handler)
         run_target(target_name, args)
 
-    def list_build_system_targets(target_name, ctx, args):
+    def list_build_system_targets(target_name: str, ctx: Context, args: PropertyDict) -> None:
         """Shows list of targets known to build sytem (make/ninja)"""
         build_target('help', ctx, args)
 
-    def menuconfig(target_name, ctx, args, style):
+    def menuconfig(target_name: str, ctx: Context, args: PropertyDict, style: str) -> None:
         """
         Menuconfig target is build_target extended with the style argument for setting the value for the environment
         variable.
@@ -61,7 +63,7 @@ def action_extensions(base_actions, project_path):
         os.environ['MENUCONFIG_STYLE'] = style
         build_target(target_name, ctx, args)
 
-    def fallback_target(target_name, ctx, args):
+    def fallback_target(target_name: str, ctx: Context, args: PropertyDict) -> None:
         """
         Execute targets that are not explicitly known to idf.py
         """
@@ -80,42 +82,22 @@ def action_extensions(base_actions, project_path):
 
         run_target(target_name, args)
 
-    def verbose_callback(ctx, param, value):
+    def verbose_callback(ctx: Context, param: List, value: str) -> Optional[str]:
         if not value or ctx.resilient_parsing:
-            return
+            return None
 
         for line in ctx.command.verbose_output:
             print(line)
 
         return value
 
-    def clean(action, ctx, args):
+    def clean(action: str, ctx: Context, args: PropertyDict) -> None:
         if not os.path.isdir(args.build_dir):
             print("Build directory '%s' not found. Nothing to clean." % args.build_dir)
             return
         build_target('clean', ctx, args)
 
-    def _delete_windows_symlinks(directory):
-        """
-        It deletes symlinks recursively on Windows. It is useful for Python 2 which doesn't detect symlinks on Windows.
-        """
-        deleted_paths = []
-        if os.name == 'nt':
-            import ctypes
-
-            for root, dirnames, _filenames in os.walk(directory):
-                for d in dirnames:
-                    full_path = os.path.join(root, d)
-                    try:
-                        full_path = full_path.decode('utf-8')
-                    except Exception:
-                        pass
-                    if ctypes.windll.kernel32.GetFileAttributesW(full_path) & 0x0400:
-                        os.rmdir(full_path)
-                        deleted_paths.append(full_path)
-        return deleted_paths
-
-    def fullclean(action, ctx, args):
+    def fullclean(action: str, ctx: Context, args: PropertyDict) -> None:
         build_dir = args.build_dir
         if not os.path.isdir(build_dir):
             print("Build directory '%s' not found. Nothing to clean." % build_dir)
@@ -135,13 +117,8 @@ def action_extensions(base_actions, project_path):
                 raise FatalError(
                     "Refusing to automatically delete files in directory containing '%s'. Delete files manually if you're sure."
                     % red)
-        # OK, delete everything in the build directory...
-        # Note: Python 2.7 doesn't detect symlinks on Windows (it is supported form 3.2). Tools promising to not
-        # follow symlinks will actually follow them. Deleting the build directory with symlinks deletes also items
-        # outside of this directory.
-        deleted_symlinks = _delete_windows_symlinks(build_dir)
-        if args.verbose and len(deleted_symlinks) > 1:
-            print('The following symlinks were identified and removed:\n%s' % '\n'.join(deleted_symlinks))
+        if args.verbose and len(build_dir) > 1:
+            print('The following symlinks were identified and removed:\n%s' % '\n'.join(build_dir))
         for f in os.listdir(build_dir):  # TODO: once we are Python 3 only, this can be os.scandir()
             f = os.path.join(build_dir, f)
             if args.verbose:
@@ -151,7 +128,7 @@ def action_extensions(base_actions, project_path):
             else:
                 os.remove(f)
 
-    def python_clean(action, ctx, args):
+    def python_clean(action: str, ctx: Context, args: PropertyDict) -> None:
         for root, dirnames, filenames in os.walk(os.environ['IDF_PATH']):
             for d in dirnames:
                 if d == '__pycache__':
@@ -165,7 +142,7 @@ def action_extensions(base_actions, project_path):
                     print('Removing: %s' % file_to_delete)
                 os.remove(file_to_delete)
 
-    def set_target(action, ctx, args, idf_target):
+    def set_target(action: str, ctx: Context, args: PropertyDict, idf_target: str) -> None:
         if (not args['preview'] and idf_target in PREVIEW_TARGETS):
             raise FatalError(
                 "%s is still in preview. You have to append '--preview' option after idf.py to use any preview feature."
@@ -180,10 +157,10 @@ def action_extensions(base_actions, project_path):
         print('Set Target to: %s, new sdkconfig created. Existing sdkconfig renamed to sdkconfig.old.' % idf_target)
         ensure_build_directory(args, ctx.info_name, True)
 
-    def reconfigure(action, ctx, args):
+    def reconfigure(action: str, ctx: Context, args: PropertyDict) -> None:
         ensure_build_directory(args, ctx.info_name, True)
 
-    def validate_root_options(ctx, args, tasks):
+    def validate_root_options(ctx: Context, args: PropertyDict, tasks: List) -> None:
         args.project_dir = realpath(args.project_dir)
         if args.build_dir is not None and args.project_dir == realpath(args.build_dir):
             raise FatalError(
@@ -193,7 +170,7 @@ def action_extensions(base_actions, project_path):
             args.build_dir = os.path.join(args.project_dir, 'build')
         args.build_dir = realpath(args.build_dir)
 
-    def idf_version_callback(ctx, param, value):
+    def idf_version_callback(ctx: Context, param: str, value: str) -> None:
         if not value or ctx.resilient_parsing:
             return
 
@@ -205,7 +182,7 @@ def action_extensions(base_actions, project_path):
         print('ESP-IDF %s' % version)
         sys.exit(0)
 
-    def list_targets_callback(ctx, param, value):
+    def list_targets_callback(ctx: Context, param: List, value: int) -> None:
         if not value or ctx.resilient_parsing:
             return
 
@@ -218,12 +195,13 @@ def action_extensions(base_actions, project_path):
 
         sys.exit(0)
 
-    def show_docs(action, ctx, args, no_browser, language, starting_page, version, target):
+    def show_docs(action: str, ctx: Context, args: PropertyDict, no_browser: bool, language: str, starting_page: str, version: str, target: str) -> None:
         if language == 'cn':
             language = 'zh_CN'
         if not version:
             # '0.0-dev' here because if 'dev' in version it will transform in to 'latest'
-            version = re.search(r'v\d+\.\d+\.?\d*(-dev|-beta\d|-rc)?', idf_version() or '0.0-dev').group()
+            version_search = re.search(r'v\d+\.\d+\.?\d*(-dev|-beta\d|-rc)?', idf_version() or '0.0-dev')
+            version = version_search.group() if version_search else 'latest'
             if 'dev' in version:
                 version = 'latest'
         elif version[0] != 'v':
@@ -249,7 +227,7 @@ def action_extensions(base_actions, project_path):
             print(link)
         sys.exit(0)
 
-    def get_default_language():
+    def get_default_language() -> str:
         try:
             language = 'zh_CN' if locale.getdefaultlocale()[0] == 'zh_CN' else 'en'
         except ValueError:

tools/idf_py_actions/create_ext.py

@@ -6,13 +6,17 @@ import os
 import re
 import sys
 from distutils.dir_util import copy_tree
+from typing import Dict
 
+import click
+from idf_py_actions.tools import PropertyDict
 
-def get_type(action):
+
+def get_type(action: str) -> str:
     return action.split('-')[1]
 
 
-def replace_in_file(filename, pattern, replacement):
+def replace_in_file(filename: str, pattern: str, replacement: str) -> None:
     with open(filename, 'r+') as f:
         content = f.read()
         overwritten_content = re.sub(pattern, replacement, content, flags=re.M)
@@ -21,7 +25,7 @@ def replace_in_file(filename, pattern, replacement):
         f.truncate()
 
 
-def is_empty_and_create(path, action):
+def is_empty_and_create(path: str, action: str) -> None:
     abspath = os.path.abspath(path)
     if not os.path.exists(abspath):
         os.makedirs(abspath)
@@ -35,7 +39,7 @@ def is_empty_and_create(path, action):
         sys.exit(3)
 
 
-def create_project(target_path, name):
+def create_project(target_path: str, name: str) -> None:
     copy_tree(os.path.join(os.environ['IDF_PATH'], 'examples', 'get-started', 'sample_project'), target_path)
     main_folder = os.path.join(target_path, 'main')
     os.rename(os.path.join(main_folder, 'main.c'), os.path.join(main_folder, '.'.join((name, 'c'))))
@@ -44,7 +48,7 @@ def create_project(target_path, name):
     os.remove(os.path.join(target_path, 'README.md'))
 
 
-def create_component(target_path, name):
+def create_component(target_path: str, name: str) -> None:
     copy_tree(os.path.join(os.environ['IDF_PATH'], 'tools', 'templates', 'sample_component'), target_path)
     os.rename(os.path.join(target_path, 'main.c'), os.path.join(target_path, '.'.join((name, 'c'))))
     os.rename(os.path.join(target_path, 'include', 'main.h'),
@@ -54,8 +58,8 @@ def create_component(target_path, name):
     replace_in_file(os.path.join(target_path, 'CMakeLists.txt'), 'main', name)
 
 
-def action_extensions(base_actions, project_path):
-    def create_new(action, ctx, global_args, **action_args):
+def action_extensions(base_actions: Dict, project_path: str) -> Dict:
+    def create_new(action: str, ctx: click.core.Context, global_args: PropertyDict, **action_args: str) -> Dict:
         target_path = action_args.get('path') or os.path.join(project_path, action_args['name'])
 
         is_empty_and_create(target_path, action)

tools/idf_py_actions/debug_ext.py

@@ -9,21 +9,22 @@ import sys
 import threading
 import time
 from threading import Thread
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 
+from click.core import Context
 from idf_py_actions.errors import FatalError
-from idf_py_actions.tools import ensure_build_directory
+from idf_py_actions.tools import PropertyDict, ensure_build_directory
 
 PYTHON = sys.executable
 
 
-def action_extensions(base_actions, project_path):
+def action_extensions(base_actions: Dict, project_path: str) -> Dict:
     OPENOCD_OUT_FILE = 'openocd_out.txt'
     GDBGUI_OUT_FILE = 'gdbgui_out.txt'
     # Internal dictionary of currently active processes, threads and their output files
-    processes = {'threads_to_join': [], 'openocd_issues': None}
+    processes: Dict = {'threads_to_join': [], 'openocd_issues': None}
 
-    def _check_for_common_openocd_issues(file_name, print_all=True):
+    def _check_for_common_openocd_issues(file_name: str, print_all: bool=True) -> Any:
         if processes['openocd_issues'] is not None:
             return processes['openocd_issues']
         try:
@@ -39,7 +40,7 @@ def action_extensions(base_actions, project_path):
             processes['openocd_issues'] = message
             return message
 
-    def _check_openocd_errors(fail_if_openocd_failed, target, ctx):
+    def _check_openocd_errors(fail_if_openocd_failed: Dict, target: str, ctx: Context) -> None:
         if fail_if_openocd_failed:
             if 'openocd' in processes and processes['openocd'] is not None:
                 p = processes['openocd']
@@ -62,7 +63,7 @@ def action_extensions(base_actions, project_path):
                 # OpenOCD exited or error message detected -> print possible output and terminate
                 raise FatalError('Action "{}" failed due to errors in OpenOCD:\n{}'.format(target, _check_for_common_openocd_issues(name)), ctx)
 
-    def _terminate_async_target(target):
+    def _terminate_async_target(target: str) -> None:
         if target in processes and processes[target] is not None:
             try:
                 if target + '_outfile' in processes:
@@ -86,11 +87,11 @@ def action_extensions(base_actions, project_path):
                 print('Failed to close/kill {}'.format(target))
             processes[target] = None  # to indicate this has ended
 
-    def is_gdb_with_python(gdb):
+    def is_gdb_with_python(gdb: str) -> bool:
         # execute simple python command to check is it supported
         return subprocess.run([gdb, '--batch-silent', '--ex', 'python import os'], stderr=subprocess.DEVNULL).returncode == 0
 
-    def create_local_gdbinit(gdb, gdbinit, elf_file):
+    def create_local_gdbinit(gdb: str, gdbinit: str, elf_file: str) -> None:
         with open(gdbinit, 'w') as f:
             if is_gdb_with_python(gdb):
                 f.write('python\n')
@@ -107,7 +108,7 @@ def action_extensions(base_actions, project_path):
             f.write('thb app_main\n')
             f.write('c\n')
 
-    def debug_cleanup():
+    def debug_cleanup() -> None:
         print('cleaning up debug targets')
         for t in processes['threads_to_join']:
             if threading.currentThread() != t:
@@ -116,7 +117,7 @@ def action_extensions(base_actions, project_path):
         _terminate_async_target('gdbgui')
         _terminate_async_target('gdb')
 
-    def post_debug(action, ctx, args, **kwargs):
+    def post_debug(action: str, ctx: Context, args: PropertyDict, **kwargs: str) -> None:
         """ Deal with asynchronous targets, such as openocd running in background """
         if kwargs['block'] == 1:
             for target in ['openocd', 'gdbgui']:
@@ -143,7 +144,7 @@ def action_extensions(base_actions, project_path):
         _terminate_async_target('openocd')
         _terminate_async_target('gdbgui')
 
-    def get_project_desc(args, ctx):
+    def get_project_desc(args: PropertyDict, ctx: Context) -> Any:
         desc_path = os.path.join(args.build_dir, 'project_description.json')
         if not os.path.exists(desc_path):
             ensure_build_directory(args, ctx.info_name)
@@ -151,7 +152,7 @@ def action_extensions(base_actions, project_path):
             project_desc = json.load(f)
             return project_desc
 
-    def openocd(action, ctx, args, openocd_scripts, openocd_commands):
+    def openocd(action: str, ctx: Context, args: PropertyDict, openocd_scripts: Optional[str], openocd_commands: str) -> None:
         """
         Execute openocd as external tool
         """
@@ -188,14 +189,14 @@ def action_extensions(base_actions, project_path):
         processes['openocd_outfile_name'] = openocd_out_name
         print('OpenOCD started as a background task {}'.format(process.pid))
 
-    def get_gdb_args(gdbinit, project_desc: Dict[str, Any]) -> List[str]:
+    def get_gdb_args(gdbinit: str, project_desc: Dict[str, Any]) -> List:
         args = ['-x={}'.format(gdbinit)]
         debug_prefix_gdbinit = project_desc.get('debug_prefix_map_gdbinit')
         if debug_prefix_gdbinit:
             args.append('-ix={}'.format(debug_prefix_gdbinit))
         return args
 
-    def gdbui(action, ctx, args, gdbgui_port, gdbinit, require_openocd):
+    def gdbui(action: str, ctx: Context, args: PropertyDict, gdbgui_port: Optional[str], gdbinit: Optional[str], require_openocd: bool) -> None:
         """
         Asynchronous GDB-UI target
         """
@@ -211,8 +212,8 @@ def action_extensions(base_actions, project_path):
         # - '"-x=foo -x=bar"', would return ['foo bar']
         # - '-x=foo', would return ['-x', 'foo'] and mess up the former option '--gdb-args'
         # so for one item, use extra double quotes. for more items, use no extra double quotes.
-        gdb_args = get_gdb_args(gdbinit, project_desc)
-        gdb_args = '"{}"'.format(' '.join(gdb_args)) if len(gdb_args) == 1 else ' '.join(gdb_args)
+        gdb_args_list = get_gdb_args(gdbinit, project_desc)
+        gdb_args = '"{}"'.format(' '.join(gdb_args_list)) if len(gdb_args_list) == 1 else ' '.join(gdb_args_list)
         args = ['gdbgui', '-g', gdb, '--gdb-args', gdb_args]
         print(args)
 
@@ -238,8 +239,8 @@ def action_extensions(base_actions, project_path):
         print('gdbgui started as a background task {}'.format(process.pid))
         _check_openocd_errors(fail_if_openocd_failed, action, ctx)
 
-    def global_callback(ctx, global_args, tasks):
-        def move_to_front(task_name):
+    def global_callback(ctx: Context, global_args: PropertyDict, tasks: List) -> None:
+        def move_to_front(task_name: str) -> None:
             for index, task in enumerate(tasks):
                 if task.name == task_name:
                     tasks.insert(0, tasks.pop(index))
@@ -264,18 +265,18 @@ def action_extensions(base_actions, project_path):
                 if task.name in ('gdb', 'gdbgui', 'gdbtui'):
                     task.action_args['require_openocd'] = True
 
-    def run_gdb(gdb_args):
+    def run_gdb(gdb_args: List) -> int:
         p = subprocess.Popen(gdb_args)
         processes['gdb'] = p
         return p.wait()
 
-    def gdbtui(action, ctx, args, gdbinit, require_openocd):
+    def gdbtui(action: str, ctx: Context, args: PropertyDict, gdbinit: str, require_openocd: bool) -> None:
         """
         Synchronous GDB target with text ui mode
         """
         gdb(action, ctx, args, 1, gdbinit, require_openocd)
 
-    def gdb(action, ctx, args, gdb_tui, gdbinit, require_openocd):
+    def gdb(action: str, ctx: Context, args: PropertyDict, gdb_tui: Optional[int], gdbinit: Optional[str], require_openocd: bool) -> None:
         """
         Synchronous GDB target
         """

tools/idf_py_actions/dfu_ext.py

@@ -1,22 +1,25 @@
 # SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
+from typing import Dict
+
+from click.core import Context
 from idf_py_actions.errors import FatalError
-from idf_py_actions.tools import ensure_build_directory, is_target_supported, run_target
+from idf_py_actions.tools import PropertyDict, ensure_build_directory, is_target_supported, run_target
 
 
-def action_extensions(base_actions, project_path):
+def action_extensions(base_actions: Dict, project_path: str) -> Dict:
 
     SUPPORTED_TARGETS = ['esp32s2']
 
-    def dfu_target(target_name, ctx, args, part_size):
+    def dfu_target(target_name: str, ctx: Context, args: PropertyDict, part_size: str) -> None:
         ensure_build_directory(args, ctx.info_name)
         run_target(target_name, args, {'ESP_DFU_PART_SIZE': part_size} if part_size else {})
 
-    def dfu_list_target(target_name, ctx, args):
+    def dfu_list_target(target_name: str, ctx: Context, args: PropertyDict) -> None:
         ensure_build_directory(args, ctx.info_name)
         run_target(target_name, args)
 
-    def dfu_flash_target(target_name, ctx, args, path):
+    def dfu_flash_target(target_name: str, ctx: Context, args: PropertyDict, path: str) -> None:
         ensure_build_directory(args, ctx.info_name)
 
         try:

tools/idf_py_actions/errors.py

@@ -1,11 +1,14 @@
 # SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
+from click.core import Context
+
+
 class FatalError(RuntimeError):
     """
     Wrapper class for runtime errors that aren't caused by bugs in idf.py or the build process.
     """
 
-    def __init__(self, message, ctx=None):
+    def __init__(self, message: str, ctx: Context=None):
         super(RuntimeError, self).__init__(message)
         # if context is defined, check for the cleanup tasks
         if ctx is not None and 'cleanup' in ctx.meta:

tools/idf_py_actions/serial_ext.py

@@ -4,18 +4,19 @@
 import json
 import os
 import sys
+from typing import Any, Dict, List
 
 import click
 from idf_monitor_base.output_helpers import yellow_print
 from idf_py_actions.errors import FatalError, NoSerialPortFoundError
 from idf_py_actions.global_options import global_options
-from idf_py_actions.tools import ensure_build_directory, get_sdkconfig_value, run_target, run_tool
+from idf_py_actions.tools import PropertyDict, ensure_build_directory, get_sdkconfig_value, run_target, run_tool
 
 PYTHON = sys.executable
 
 
-def action_extensions(base_actions, project_path):
-    def _get_project_desc(ctx, args):
+def action_extensions(base_actions: Dict, project_path: str) -> Dict:
+    def _get_project_desc(ctx: click.core.Context, args: PropertyDict) -> Any:
         desc_path = os.path.join(args.build_dir, 'project_description.json')
         if not os.path.exists(desc_path):
             ensure_build_directory(args, ctx.info_name)
@@ -23,7 +24,7 @@ def action_extensions(base_actions, project_path):
             project_desc = json.load(f)
         return project_desc
 
-    def _get_default_serial_port(args):
+    def _get_default_serial_port(args: PropertyDict) -> Any:
         # Import is done here in order to move it after the check_environment() ensured that pyserial has been installed
         try:
             import esptool
@@ -45,7 +46,7 @@ def action_extensions(base_actions, project_path):
         except Exception as e:
             raise FatalError('An exception occurred during detection of the serial port: {}'.format(e))
 
-    def _get_esptool_args(args):
+    def _get_esptool_args(args: PropertyDict) -> List:
         esptool_path = os.path.join(os.environ['IDF_PATH'], 'components/esptool_py/esptool/esptool.py')
         esptool_wrapper_path = os.environ.get('ESPTOOL_WRAPPER', '')
         if args.port is None:
@@ -68,7 +69,7 @@ def action_extensions(base_actions, project_path):
             result += ['--no-stub']
         return result
 
-    def _get_commandline_options(ctx):
+    def _get_commandline_options(ctx: click.core.Context) -> List:
         """ Return all the command line options up to first action """
         # This approach ignores argument parsing done Click
         result = []
@@ -81,7 +82,8 @@ def action_extensions(base_actions, project_path):
 
         return result
 
-    def monitor(action, ctx, args, print_filter, monitor_baud, encrypted, no_reset, timestamps, timestamp_format):
+    def monitor(action: str, ctx: click.core.Context, args: PropertyDict, print_filter: str, monitor_baud: str, encrypted: bool,
+                no_reset: bool, timestamps: bool, timestamp_format: str) -> None:
         """
         Run idf_monitor.py to watch build output
         """
@@ -152,7 +154,7 @@ def action_extensions(base_actions, project_path):
 
         run_tool('idf_monitor', monitor_args, args.project_dir)
 
-    def flash(action, ctx, args):
+    def flash(action: str, ctx: click.core.Context, args: PropertyDict) -> None:
         """
         Run esptool to flash the entire project, from an argfile generated by the build system
         """
@@ -165,13 +167,13 @@ def action_extensions(base_actions, project_path):
         esp_port = args.port or _get_default_serial_port(args)
         run_target(action, args, {'ESPBAUD': str(args.baud), 'ESPPORT': esp_port})
 
-    def erase_flash(action, ctx, args):
+    def erase_flash(action: str, ctx: click.core.Context, args: PropertyDict) -> None:
         ensure_build_directory(args, ctx.info_name)
         esptool_args = _get_esptool_args(args)
         esptool_args += ['erase_flash']
         run_tool('esptool.py', esptool_args, args.build_dir)
 
-    def global_callback(ctx, global_args, tasks):
+    def global_callback(ctx: click.core.Context, global_args: Dict, tasks: PropertyDict) -> None:
         encryption = any([task.name in ('encrypted-flash', 'encrypted-app-flash') for task in tasks])
         if encryption:
             for task in tasks:
@@ -179,7 +181,7 @@ def action_extensions(base_actions, project_path):
                     task.action_args['encrypted'] = True
                     break
 
-    def ota_targets(target_name, ctx, args):
+    def ota_targets(target_name: str, ctx: click.core.Context, args: PropertyDict) -> None:
         """
         Execute the target build system to build target 'target_name'.
         Additionally set global variables for baud and port.

tools/idf_py_actions/tools.py

@@ -5,6 +5,7 @@ import re
 import subprocess
 import sys
 from io import open
+from typing import Any, List
 
 import click
 
@@ -340,12 +341,12 @@ class TargetChoice(click.Choice):
     - ignores hyphens
     - not case sensitive
     """
-    def __init__(self, choices):
+    def __init__(self, choices: List) -> None:
         super(TargetChoice, self).__init__(choices, case_sensitive=False)
 
-    def convert(self, value, param, ctx):
-        def normalize(str):
-            return str.lower().replace('-', '')
+    def convert(self, value: Any, param: click.Parameter, ctx: click.Context) -> Any:
+        def normalize(string: str) -> str:
+            return string.lower().replace('-', '')
 
         saved_token_normalize_func = ctx.token_normalize_func
         ctx.token_normalize_func = normalize
@@ -354,3 +355,20 @@ class TargetChoice(click.Choice):
             return super(TargetChoice, self).convert(value, param, ctx)
         finally:
             ctx.token_normalize_func = saved_token_normalize_func
+
+
+class PropertyDict(dict):
+    def __getattr__(self, name: str) -> Any:
+        if name in self:
+            return self[name]
+        else:
+            raise AttributeError("'PropertyDict' object has no attribute '%s'" % name)
+
+    def __setattr__(self, name: str, value: Any) -> None:
+        self[name] = value
+
+    def __delattr__(self, name: str) -> None:
+        if name in self:
+            del self[name]
+        else:
+            raise AttributeError("'PropertyDict' object has no attribute '%s'" % name)

tools/idf_py_actions/uf2_ext.py

@@ -1,10 +1,13 @@
 # SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
 # SPDX-License-Identifier: Apache-2.0
-from idf_py_actions.tools import ensure_build_directory, run_target
+from typing import Dict, List
 
+from click.core import Context
+from idf_py_actions.tools import PropertyDict, ensure_build_directory, run_target
 
-def action_extensions(base_actions, project_path):
-    def uf2_target(target_name, ctx, args):
+
+def action_extensions(base_actions: Dict, project_path: List) -> Dict:
+    def uf2_target(target_name: str, ctx: Context, args: PropertyDict) -> None:
         ensure_build_directory(args, ctx.info_name)
         run_target(target_name, args)
 

tools/mkuf2.py

@@ -11,11 +11,12 @@ import json
 import os
 import struct
 from functools import partial
+from typing import Dict, List
 
 from future.utils import iteritems
 
 
-def round_up_int_div(n, d):
+def round_up_int_div(n: int, d: int) -> int:
     # equivalent to math.ceil(n / d)
     return (n + d - 1) // d
 
@@ -32,23 +33,23 @@ class UF2Writer(object):
     UF2_FLAG_FAMILYID_PRESENT = 0x00002000
     UF2_FLAG_MD5_PRESENT = 0x00004000
 
-    def __init__(self, chip_id, output_file, chunk_size):
+    def __init__(self, chip_id: int, output_file: os.PathLike, chunk_size: int) -> None:
         self.chip_id = chip_id
         self.CHUNK_SIZE = self.UF2_DATA_SIZE - self.UF2_MD5_PART_SIZE if chunk_size is None else chunk_size
         self.f = open(output_file, 'wb')
 
-    def __enter__(self):
+    def __enter__(self) -> 'UF2Writer':
         return self
 
-    def __exit__(self, exc_type, exc_val, exc_tb):
+    def __exit__(self, exc_type: str, exc_val: int, exc_tb: List) -> None:
         if self.f:
             self.f.close()
 
     @staticmethod
-    def _to_uint32(num):
+    def _to_uint32(num: int) -> bytes:
         return struct.pack('<I', num)
 
-    def _write_block(self, addr, chunk, len_chunk, block_no, blocks):
+    def _write_block(self, addr: int, chunk: bytes, len_chunk: int, block_no: int, blocks: int) -> None:
         assert len_chunk > 0
         assert len_chunk <= self.CHUNK_SIZE
         assert block_no < blocks
@@ -73,7 +74,7 @@ class UF2Writer(object):
         assert len(block) == self.UF2_BLOCK_SIZE
         self.f.write(block)
 
-    def add_file(self, addr, f_path):
+    def add_file(self, addr: int, f_path: os.PathLike) -> None:
         blocks = round_up_int_div(os.path.getsize(f_path), self.CHUNK_SIZE)
         with open(f_path, 'rb') as fin:
             a = addr
@@ -83,7 +84,7 @@ class UF2Writer(object):
                 a += len_chunk
 
 
-def action_write(args):
+def action_write(args: Dict) -> None:
     with UF2Writer(args['chip_id'], args['output_file'], args['chunk_size']) as writer:
         for addr, f in args['files']:
             print('Adding {} at {:#x}'.format(f, addr))
@@ -91,19 +92,19 @@ def action_write(args):
     print('"{}" has been written.'.format(args['output_file']))
 
 
-def main():
+def main() -> None:
     parser = argparse.ArgumentParser()
 
-    def four_byte_aligned(integer):
+    def four_byte_aligned(integer: int) -> bool:
         return integer & 3 == 0
 
-    def parse_chunk_size(string):
+    def parse_chunk_size(string: str) -> int:
         num = int(string, 0)
         if not four_byte_aligned(num):
             raise argparse.ArgumentTypeError('Chunk size should be a 4-byte aligned number')
         return num
 
-    def parse_chip_id(string):
+    def parse_chip_id(string: str) -> int:
         num = int(string, 16)
         if num < 0 or num > 0xFFFFFFFF:
             raise argparse.ArgumentTypeError('Chip ID should be a 4-byte unsigned integer')
@@ -137,12 +138,12 @@ def main():
 
     args = parser.parse_args()
 
-    def check_file(file_name):
+    def check_file(file_name: str) -> str:
         if not os.path.isfile(file_name):
             raise RuntimeError('{} is not a regular file!'.format(file_name))
         return file_name
 
-    def parse_addr(string):
+    def parse_addr(string: str) -> int:
         num = int(string, 0)
         if not four_byte_aligned(num):
             raise RuntimeError('{} is not a 4-byte aligned valid address'.format(string))
@@ -155,7 +156,7 @@ def main():
     if args.json:
         json_dir = os.path.dirname(os.path.abspath(args.json))
 
-        def process_json_file(path):
+        def process_json_file(path: str) -> str:
             '''
             The input path is relative to json_dir. This function makes it relative to the current working
             directory.