Add more type hints

slither/analyses/data_dependency/data_dependency.py

@@ -37,7 +37,12 @@ if TYPE_CHECKING:
 ###################################################################################
 
 
-def is_dependent(variable, source, context, only_unprotected=False):
+def is_dependent(
+    variable: Variable,
+    source: Variable,
+    context: Union[Contract, Function],
+    only_unprotected: bool = False,
+) -> bool:
     """
     Args:
         variable (Variable)
@@ -52,17 +57,22 @@ def is_dependent(variable, source, context, only_unprotected=False):
         return False
     if variable == source:
         return True
-    context = context.context
+    context_dict = context.context
 
     if only_unprotected:
         return (
-            variable in context[KEY_NON_SSA_UNPROTECTED]
+            variable in context_dict[KEY_NON_SSA_UNPROTECTED]
-            and source in context[KEY_NON_SSA_UNPROTECTED][variable]
+            and source in context_dict[KEY_NON_SSA_UNPROTECTED][variable]
         )
-    return variable in context[KEY_NON_SSA] and source in context[KEY_NON_SSA][variable]
+    return variable in context_dict[KEY_NON_SSA] and source in context_dict[KEY_NON_SSA][variable]
 
 
-def is_dependent_ssa(variable, source, context, only_unprotected=False):
+def is_dependent_ssa(
+    variable: Variable,
+    source: Variable,
+    context: Union[Contract, Function],
+    only_unprotected: bool = False,
+) -> bool:
     """
     Args:
         variable (Variable)
@@ -73,17 +83,17 @@ def is_dependent_ssa(variable, source, context, only_unprotected=False):
         bool
     """
     assert isinstance(context, (Contract, Function))
-    context = context.context
+    context_dict = context.context
     if isinstance(variable, Constant):
         return False
     if variable == source:
         return True
     if only_unprotected:
         return (
-            variable in context[KEY_SSA_UNPROTECTED]
+            variable in context_dict[KEY_SSA_UNPROTECTED]
-            and source in context[KEY_SSA_UNPROTECTED][variable]
+            and source in context_dict[KEY_SSA_UNPROTECTED][variable]
         )
-    return variable in context[KEY_SSA] and source in context[KEY_SSA][variable]
+    return variable in context_dict[KEY_SSA] and source in context_dict[KEY_SSA][variable]
 
 
 GENERIC_TAINT = {

slither/core/context/context.py

@@ -3,9 +3,9 @@ from typing import Dict
 
 
 class Context:  # pylint: disable=too-few-public-methods
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
-        self._context = {"MEMBERS": defaultdict(None)}
+        self._context: Dict = {"MEMBERS": defaultdict(None)}
 
     @property
     def context(self) -> Dict:

slither/core/declarations/function.py

@@ -104,7 +104,7 @@ def _filter_state_variables_written(expressions: List["Expression"]):
     return ret
 
 
-class Function(metaclass=ABCMeta):  # pylint: disable=too-many-public-methods
+class Function(SourceMapping, metaclass=ABCMeta):  # pylint: disable=too-many-public-methods
     """
     Function class
     """

slither/core/declarations/function_contract.py

@@ -5,7 +5,6 @@ from typing import TYPE_CHECKING, List, Tuple
 
 from slither.core.children.child_contract import ChildContract
 from slither.core.children.child_inheritance import ChildInheritance
-from slither.core.source_mapping.source_mapping import SourceMapping
 from slither.core.declarations import Function
 
 # pylint: disable=import-outside-toplevel,too-many-instance-attributes,too-many-statements,too-many-lines
@@ -14,7 +13,7 @@ if TYPE_CHECKING:
     from slither.core.declarations import Contract
 
 
-class FunctionContract(Function, ChildContract, ChildInheritance, SourceMapping):
+class FunctionContract(Function, ChildContract, ChildInheritance):
     @property
     def canonical_name(self) -> str:
         """

slither/core/declarations/function_top_level.py

@@ -5,10 +5,9 @@ from typing import List, Tuple
 
 from slither.core.declarations import Function
 from slither.core.declarations.top_level import TopLevel
-from slither.core.source_mapping.source_mapping import SourceMapping
 
 
-class FunctionTopLevel(Function, TopLevel, SourceMapping):
+class FunctionTopLevel(Function, TopLevel):
     @property
     def canonical_name(self) -> str:
         """

slither/core/expressions/assignment_operation.py

@@ -26,7 +26,7 @@ class AssignmentOperationType(Enum):
     ASSIGN_MODULO = 10  # %=
 
     @staticmethod
-    def get_type(operation_type: "AssignmentOperationType"):
+    def get_type(operation_type: str) -> "AssignmentOperationType":
         if operation_type == "=":
             return AssignmentOperationType.ASSIGN
         if operation_type == "|=":
@@ -52,7 +52,7 @@ class AssignmentOperationType(Enum):
 
         raise SlitherCoreError("get_type: Unknown operation type {})".format(operation_type))
 
-    def __str__(self):
+    def __str__(self) -> str:
         if self == AssignmentOperationType.ASSIGN:
             return "="
         if self == AssignmentOperationType.ASSIGN_OR:
@@ -91,7 +91,7 @@ class AssignmentOperation(ExpressionTyped):
         super().__init__()
         left_expression.set_lvalue()
         self._expressions = [left_expression, right_expression]
-        self._type: Optional["Type"] = expression_type
+        self._type: Optional["AssignmentOperationType"] = expression_type
         self._expression_return_type: Optional["Type"] = expression_return_type
 
     @property
@@ -111,8 +111,8 @@ class AssignmentOperation(ExpressionTyped):
         return self._expressions[1]
 
     @property
-    def type(self) -> Optional["Type"]:
+    def type(self) -> Optional["AssignmentOperationType"]:
         return self._type
 
-    def __str__(self):
+    def __str__(self) -> str:
         return str(self.expression_left) + " " + str(self.type) + " " + str(self.expression_right)

slither/core/expressions/expression.py

@@ -10,5 +10,5 @@ class Expression(SourceMapping):
     def is_lvalue(self) -> bool:
         return self._is_lvalue
 
-    def set_lvalue(self):
+    def set_lvalue(self) -> None:
         self._is_lvalue = True

slither/core/source_mapping/source_mapping.py

@@ -8,7 +8,7 @@ if TYPE_CHECKING:
 
 
 class SourceMapping(Context):
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__()
         # TODO create a namedtuple for the source mapping rather than a dict
         self._source_mapping: Optional[Dict] = None

slither/detectors/abstract_detector.py

@@ -1,6 +1,8 @@
 import abc
 import re
-from typing import Optional, List, TYPE_CHECKING
+from functools import partial
+from logging import Logger
+from typing import Optional, List, TYPE_CHECKING, Dict, Union, Callable
 
 from slither.core.compilation_unit import SlitherCompilationUnit
 from slither.core.declarations import Contract
@@ -8,7 +10,7 @@ from slither.utils.colors import green, yellow, red
 from slither.formatters.exceptions import FormatImpossible
 from slither.formatters.utils.patches import apply_patch, create_diff
 from slither.utils.comparable_enum import ComparableEnum
-from slither.utils.output import Output
+from slither.utils.output import Output, SupportedOutput
 
 if TYPE_CHECKING:
     from slither import Slither
@@ -25,8 +27,10 @@ class DetectorClassification(ComparableEnum):
     INFORMATIONAL = 3
     OPTIMIZATION = 4
 
+    UNIMPLEMENTED = 999
 
-classification_colors = {
+
+classification_colors: Dict[DetectorClassification, Callable[[str], str]] = {
     DetectorClassification.INFORMATIONAL: green,
     DetectorClassification.OPTIMIZATION: green,
     DetectorClassification.LOW: green,
@@ -46,8 +50,8 @@ classification_txt = {
 class AbstractDetector(metaclass=abc.ABCMeta):
     ARGUMENT = ""  # run the detector with slither.py --ARGUMENT
     HELP = ""  # help information
-    IMPACT: Optional[DetectorClassification] = None
+    IMPACT: DetectorClassification = DetectorClassification.UNIMPLEMENTED
-    CONFIDENCE: Optional[DetectorClassification] = None
+    CONFIDENCE: DetectorClassification = DetectorClassification.UNIMPLEMENTED
 
     WIKI = ""
 
@@ -58,7 +62,9 @@ class AbstractDetector(metaclass=abc.ABCMeta):
 
     STANDARD_JSON = True
 
-    def __init__(self, compilation_unit: SlitherCompilationUnit, slither, logger):
+    def __init__(
+        self, compilation_unit: SlitherCompilationUnit, slither: "Slither", logger: Logger
+    ):
         self.compilation_unit: SlitherCompilationUnit = compilation_unit
         self.contracts: List[Contract] = compilation_unit.contracts
         self.slither: "Slither" = slither
@@ -130,32 +136,25 @@ class AbstractDetector(metaclass=abc.ABCMeta):
                 "CONFIDENCE is not initialized {}".format(self.__class__.__name__)
             )
 
-    def _log(self, info):
+    def _log(self, info: str) -> None:
         if self.logger:
             self.logger.info(self.color(info))
 
     @abc.abstractmethod
-    def _detect(self):
+    def _detect(self) -> List[Output]:
         """TODO Documentation"""
         return []
 
     # pylint: disable=too-many-branches
-    def detect(self):
+    def detect(self) -> List[Dict]:
-        results = []
+        results: List[Dict] = []
         # only keep valid result, and remove dupplicate
         # Keep only dictionaries
-        for r in [r.data for r in self._detect()]:
+        for r in [output.data for output in self._detect()]:
             if self.compilation_unit.core.valid_result(r) and r not in results:
                 results.append(r)
-        if results:
+        if results and self.logger:
-            if self.logger:
+            self._log_result(results)
-                info = "\n"
-                for idx, result in enumerate(results):
-                    if self.slither.triage_mode:
-                        info += "{}: ".format(idx)
-                    info += result["description"]
-                info += "Reference: {}".format(self.WIKI)
-                self._log(info)
         if self.compilation_unit.core.generate_patches:
             for result in results:
                 try:
@@ -205,20 +204,24 @@ class AbstractDetector(metaclass=abc.ABCMeta):
                 if indexes.endswith("]"):
                     indexes = indexes[:-1]
                 try:
-                    indexes = [int(i) for i in indexes.split(",")]
+                    indexes_converted = [int(i) for i in indexes.split(",")]
                     self.slither.save_results_to_hide(
-                        [r for (idx, r) in enumerate(results) if idx in indexes]
+                        [r for (idx, r) in enumerate(results) if idx in indexes_converted]
                     )
-                    return [r for (idx, r) in enumerate(results) if idx not in indexes]
+                    return [r for (idx, r) in enumerate(results) if idx not in indexes_converted]
                 except ValueError:
                     self.logger.error(yellow("Malformed input. Example of valid input: 0,1,2,3"))
         return results
 
     @property
-    def color(self):
+    def color(self) -> Callable[[str], str]:
         return classification_colors[self.IMPACT]
 
-    def generate_result(self, info, additional_fields=None):
+    def generate_result(
+        self,
+        info: Union[str, List[Union[str, SupportedOutput]]],
+        additional_fields: Optional[Dict] = None,
+    ) -> Output:
         output = Output(
             info,
             additional_fields,
@@ -233,6 +236,15 @@ class AbstractDetector(metaclass=abc.ABCMeta):
         return output
 
     @staticmethod
-    def _format(_compilation_unit: SlitherCompilationUnit, _result):
+    def _format(_compilation_unit: SlitherCompilationUnit, _result: Dict) -> None:
         """Implement format"""
         return
+
+    def _log_result(self, results: List[Dict]) -> None:
+        info = "\n"
+        for idx, result in enumerate(results):
+            if self.slither.triage_mode:
+                info += "{}: ".format(idx)
+            info += result["description"]
+        info += "Reference: {}".format(self.WIKI)
+        self._log(info)

slither/detectors/functions/arbitrary_send.py

@@ -9,7 +9,10 @@
 
     TODO: dont report if the value is tainted by msg.value
 """
-from slither.core.declarations import Function
+from typing import List
+
+from slither.core.cfg.node import Node
+from slither.core.declarations import Function, Contract
 from slither.analyses.data_dependency.data_dependency import is_tainted, is_dependent
 from slither.core.declarations.solidity_variables import (
     SolidityFunction,
@@ -27,11 +30,14 @@ from slither.slithir.operations import (
 
 
 # pylint: disable=too-many-nested-blocks,too-many-branches
-def arbitrary_send(func):
+from slither.utils.output import Output
+
+
+def arbitrary_send(func: Function):
     if func.is_protected():
         return []
 
-    ret = []
+    ret: List[Node] = []
     for node in func.nodes:
         for ir in node.irs:
             if isinstance(ir, SolidityCall):
@@ -68,7 +74,7 @@ def arbitrary_send(func):
     return ret
 
 
-def detect_arbitrary_send(contract):
+def detect_arbitrary_send(contract: Contract):
     """
         Detect arbitrary send
     Args:
@@ -114,7 +120,7 @@ Bob calls `setDestination` and `withdraw`. As a result he withdraws the contract
 
     WIKI_RECOMMENDATION = "Ensure that an arbitrary user cannot withdraw unauthorized funds."
 
-    def _detect(self):
+    def _detect(self) -> List[Output]:
         """"""
         results = []
 

slither/detectors/operations/bad_prng.py

@@ -2,18 +2,24 @@
 Module detecting bad PRNG due to the use of block.timestamp, now or blockhash (block.blockhash) as a source of randomness
 """
 
+from typing import List, Tuple
+
 from slither.analyses.data_dependency.data_dependency import is_dependent_ssa
+from slither.core.cfg.node import Node
+from slither.core.declarations import Function, Contract
 from slither.core.declarations.solidity_variables import (
     SolidityVariable,
     SolidityFunction,
     SolidityVariableComposed,
 )
+from slither.core.variables.variable import Variable
 from slither.detectors.abstract_detector import AbstractDetector, DetectorClassification
 from slither.slithir.operations import BinaryType, Binary
 from slither.slithir.operations import SolidityCall
+from slither.utils.output import Output, AllSupportedOutput
 
 
-def collect_return_values_of_bad_PRNG_functions(f):
+def collect_return_values_of_bad_PRNG_functions(f: Function) -> List:
     """
         Return the return-values of calls to blockhash()
     Args:
@@ -33,7 +39,7 @@ def collect_return_values_of_bad_PRNG_functions(f):
     return values_returned
 
 
-def contains_bad_PRNG_sources(func, blockhash_ret_values):
+def contains_bad_PRNG_sources(func: Function, blockhash_ret_values: List[Variable]) -> List[Node]:
     """
          Check if any node in function has a modulus operator and the first operand is dependent on block.timestamp, now or blockhash()
     Returns:
@@ -57,7 +63,7 @@ def contains_bad_PRNG_sources(func, blockhash_ret_values):
     return list(ret)
 
 
-def detect_bad_PRNG(contract):
+def detect_bad_PRNG(contract: Contract) -> List[Tuple[Function, List[Node]]]:
     """
     Args:
         contract (Contract)
@@ -67,7 +73,7 @@ def detect_bad_PRNG(contract):
     blockhash_ret_values = []
     for f in contract.functions:
         blockhash_ret_values += collect_return_values_of_bad_PRNG_functions(f)
-    ret = []
+    ret: List[Tuple[Function, List[Node]]] = []
     for f in contract.functions:
         bad_prng_nodes = contains_bad_PRNG_sources(f, blockhash_ret_values)
         if bad_prng_nodes:
@@ -110,7 +116,7 @@ As a result, Eve wins the game."""
         "Do not use `block.timestamp`, `now` or `blockhash` as a source of randomness"
     )
 
-    def _detect(self):
+    def _detect(self) -> List[Output]:
         """Detect bad PRNG due to the use of block.timestamp, now or blockhash (block.blockhash) as a source of randomness"""
         results = []
         for c in self.compilation_unit.contracts_derived:
@@ -118,7 +124,7 @@ As a result, Eve wins the game."""
             for func, nodes in values:
 
                 for node in nodes:
-                    info = [func, ' uses a weak PRNG: "', node, '" \n']
+                    info: List[AllSupportedOutput] = [func, ' uses a weak PRNG: "', node, '" \n']
                     res = self.generate_result(info)
                     results.append(res)
 

slither/detectors/shadowing/abstract.py

@@ -2,19 +2,24 @@
 Module detecting shadowing variables on abstract contract
 Recursively check the called functions
 """
+from typing import List
 
+from slither.core.declarations import Contract
+from slither.core.variables.state_variable import StateVariable
 from slither.detectors.abstract_detector import AbstractDetector, DetectorClassification
+from slither.utils.output import Output, AllSupportedOutput
 
 
-def detect_shadowing(contract):
+def detect_shadowing(contract: Contract) -> List[List[StateVariable]]:
-    ret = []
+    ret: List[List[StateVariable]] = []
     variables_fathers = []
     for father in contract.inheritance:
-        if all(not f.is_implemented for f in father.functions + father.modifiers):
+        if all(not f.is_implemented for f in father.functions + list(father.modifiers)):
             variables_fathers += father.state_variables_declared
 
+    var: StateVariable
     for var in contract.state_variables_declared:
-        shadow = [v for v in variables_fathers if v.name == var.name]
+        shadow: List[StateVariable] = [v for v in variables_fathers if v.name == var.name]
         if shadow:
             ret.append([var] + shadow)
     return ret
@@ -51,7 +56,7 @@ contract DerivedContract is BaseContract{
 
     WIKI_RECOMMENDATION = "Remove the state variable shadowing."
 
-    def _detect(self):
+    def _detect(self) -> List[Output]:
         """Detect shadowing
 
         Recursively visit the calls
@@ -59,14 +64,14 @@ contract DerivedContract is BaseContract{
             list: {'vuln', 'filename,'contract','func', 'shadow'}
 
         """
-        results = []
+        results: List[Output] = []
         for contract in self.contracts:
             shadowing = detect_shadowing(contract)
             if shadowing:
                 for all_variables in shadowing:
                     shadow = all_variables[0]
                     variables = all_variables[1:]
-                    info = [shadow, " shadows:\n"]
+                    info: List[AllSupportedOutput] = [shadow, " shadows:\n"]
                     for var in variables:
                         info += ["\t- ", var, "\n"]
 

slither/formatters/utils/patches.py

@@ -1,9 +1,19 @@
 import os
 import difflib
+from typing import Dict, Tuple, Union
 from collections import defaultdict
 
-
+from slither.core.compilation_unit import SlitherCompilationUnit
-def create_patch(result, file, start, end, old_str, new_str):  # pylint: disable=too-many-arguments
+
+# pylint: disable=too-many-arguments
+def create_patch(
+    result: Dict,
+    file: str,
+    start: int,
+    end: int,
+    old_str: Union[str, bytes],
+    new_str: Union[str, bytes],
+) -> None:
     if isinstance(old_str, bytes):
         old_str = old_str.decode("utf8")
     if isinstance(new_str, bytes):
@@ -15,7 +25,7 @@ def create_patch(result, file, start, end, old_str, new_str):  # pylint: disable
         result["patches"][file].append(p)
 
 
-def apply_patch(original_txt, patch, offset):
+def apply_patch(original_txt: bytes, patch: Dict, offset: int) -> Tuple[bytes, int]:
     patched_txt = original_txt[: int(patch["start"] + offset)]
     patched_txt += patch["new_string"].encode("utf8")
     patched_txt += original_txt[int(patch["end"] + offset) :]
@@ -25,9 +35,11 @@ def apply_patch(original_txt, patch, offset):
     return patched_txt, patch_length_diff + offset
 
 
-def create_diff(slither, original_txt, patched_txt, filename):
+def create_diff(
-    if slither.crytic_compile:
+    compilation_unit: SlitherCompilationUnit, original_txt: bytes, patched_txt: bytes, filename: str
-        relative_path = slither.crytic_compile.filename_lookup(filename).relative
+) -> str:
+    if compilation_unit.crytic_compile:
+        relative_path = compilation_unit.crytic_compile.filename_lookup(filename).relative
         relative_path = os.path.join(".", relative_path)
     else:
         relative_path = filename

slither/tools/kspec_coverage/analysis.py

@@ -1,5 +1,6 @@
 import re
 import logging
+from typing import Set, Tuple
 
 from slither.core.declarations import Function
 from slither.core.variables.variable import Variable
@@ -13,13 +14,13 @@ logger = logging.getLogger("Slither.kspec")
 # pylint: disable=anomalous-backslash-in-string
 
 
-def _refactor_type(targeted_type):
+def _refactor_type(targeted_type: str) -> str:
     return {"uint": "uint256", "int": "int256"}.get(targeted_type, targeted_type)
 
 
-def _get_all_covered_kspec_functions(target):
+def _get_all_covered_kspec_functions(target: str) -> Set[Tuple[str, str]]:
     # Create a set of our discovered functions which are covered
-    covered_functions = set()
+    covered_functions: Set[Tuple[str, str]] = set()
 
     BEHAVIOUR_PATTERN = re.compile("behaviour\s+(\S+)\s+of\s+(\S+)")
     INTERFACE_PATTERN = re.compile("interface\s+([^\r\n]+)")

slither/tools/mutator/mutators/abstract_mutator.py

@@ -69,14 +69,14 @@ class AbstractMutator(metaclass=abc.ABCMeta):  # pylint: disable=too-few-public-
         """TODO Documentation"""
         return dict()
 
-    def mutate(self):
+    def mutate(self) -> None:
-        patches = self._mutate()
+        all_patches = self._mutate()
 
-        for file in patches["patches"]:
+        for file in all_patches["patches"]:
             original_txt = self.slither.source_code[file].encode("utf8")
             patched_txt = original_txt
             offset = 0
-            patches = patches["patches"][file]
+            patches = all_patches["patches"][file]
             patches.sort(key=lambda x: x["start"])
             if not all(patches[i]["end"] <= patches[i + 1]["end"] for i in range(len(patches) - 1)):
                 logger.info(f"Impossible to generate patch; patches collisions: {patches}")

slither/tools/possible_paths/__main__.py

@@ -2,6 +2,8 @@ import argparse
 import sys
 
 import logging
+from argparse import ArgumentParser
+
 from crytic_compile import cryticparser
 from slither import Slither
 from slither.utils.colors import red
@@ -15,12 +17,12 @@ logging.basicConfig()
 logging.getLogger("Slither").setLevel(logging.INFO)
 
 
-def parse_args():
+def parse_args() -> argparse.Namespace:
     """
     Parse the underlying arguments for the program.
     :return: Returns the arguments for the program.
     """
-    parser = argparse.ArgumentParser(
+    parser: ArgumentParser = argparse.ArgumentParser(
         description="PossiblePaths",
         usage="possible_paths.py filename [contract.function targets]",
     )
@@ -36,7 +38,7 @@ def parse_args():
     return parser.parse_args()
 
 
-def main():
+def main() -> None:
     # ------------------------------
     # PossiblePaths.py
     #       Usage: python3 possible_paths.py filename targets

slither/tools/upgradeability/__main__.py

@@ -20,7 +20,7 @@ from slither.tools.upgradeability.utils.command_line import (
 )
 
 logging.basicConfig()
-logger = logging.getLogger("Slither")
+logger: logging.Logger = logging.getLogger("Slither")
 logger.setLevel(logging.INFO)
 
 

slither/tools/upgradeability/checks/abstract_checks.py

@@ -1,9 +1,11 @@
 import abc
-from typing import Optional
+from logging import Logger
+from typing import Optional, List, Dict, Union, Callable
 
+from slither.core.declarations import Contract
 from slither.utils.colors import green, yellow, red
 from slither.utils.comparable_enum import ComparableEnum
-from slither.utils.output import Output
+from slither.utils.output import Output, SupportedOutput
 
 
 class IncorrectCheckInitialization(Exception):
@@ -15,9 +17,10 @@ class CheckClassification(ComparableEnum):
     MEDIUM = 1
     LOW = 2
     INFORMATIONAL = 3
+    UNIMPLEMENTED = 999
 
 
-classification_colors = {
+classification_colors: Dict[CheckClassification, Callable[[str], str]] = {
     CheckClassification.INFORMATIONAL: green,
     CheckClassification.LOW: yellow,
     CheckClassification.MEDIUM: yellow,
@@ -35,7 +38,7 @@ classification_txt = {
 class AbstractCheck(metaclass=abc.ABCMeta):
     ARGUMENT = ""
     HELP = ""
-    IMPACT: Optional[CheckClassification] = None
+    IMPACT: CheckClassification = CheckClassification.UNIMPLEMENTED
 
     WIKI = ""
 
@@ -48,7 +51,13 @@ class AbstractCheck(metaclass=abc.ABCMeta):
     REQUIRE_PROXY = False
     REQUIRE_CONTRACT_V2 = False
 
-    def __init__(self, logger, contract, proxy=None, contract_v2=None):
+    def __init__(
+        self,
+        logger: Logger,
+        contract: Contract,
+        proxy: Optional[Contract] = None,
+        contract_v2: Optional[Contract] = None,
+    ) -> None:
         self.logger = logger
         self.contract = contract
         self.proxy = proxy
@@ -120,14 +129,14 @@ class AbstractCheck(metaclass=abc.ABCMeta):
             )
 
     @abc.abstractmethod
-    def _check(self):
+    def _check(self) -> List[Output]:
         """TODO Documentation"""
         return []
 
-    def check(self):
+    def check(self) -> List[Dict]:
-        all_results = self._check()
+        all_outputs = self._check()
         # Keep only dictionaries
-        all_results = [r.data for r in all_results]
+        all_results = [r.data for r in all_outputs]
         if all_results:
             if self.logger:
                 info = "\n"
@@ -137,7 +146,11 @@ class AbstractCheck(metaclass=abc.ABCMeta):
                 self._log(info)
         return all_results
 
-    def generate_result(self, info, additional_fields=None):
+    def generate_result(
+        self,
+        info: Union[str, List[Union[str, SupportedOutput]]],
+        additional_fields: Optional[Dict] = None,
+    ) -> Output:
         output = Output(
             info, additional_fields, markdown_root=self.contract.compilation_unit.core.markdown_root
         )
@@ -146,10 +159,10 @@ class AbstractCheck(metaclass=abc.ABCMeta):
 
         return output
 
-    def _log(self, info):
+    def _log(self, info: str) -> None:
         if self.logger:
             self.logger.info(self.color(info))
 
     @property
-    def color(self):
+    def color(self) -> Callable[[str], str]:
         return classification_colors[self.IMPACT]

slither/utils/myprettytable.py

@@ -8,7 +8,7 @@ class MyPrettyTable:
         self._field_names = field_names
         self._rows: List = []
 
-    def add_row(self, row):
+    def add_row(self, row: List[str]) -> None:
         self._rows.append(row)
 
     def to_pretty_table(self) -> PrettyTable:
@@ -20,5 +20,5 @@ class MyPrettyTable:
     def to_json(self) -> Dict:
         return {"fields_names": self._field_names, "rows": self._rows}
 
-    def __str__(self):
+    def __str__(self) -> str:
         return str(self.to_pretty_table())

slither/utils/output.py

@@ -215,6 +215,7 @@ def _create_parent_element(element):
 
 
 SupportedOutput = Union[Variable, Contract, Function, Enum, Event, Structure, Pragma, Node]
+AllSupportedOutput = Union[str, SupportedOutput]
 
 
 class Output: