Check static typing

Author: angely-dev

Diff for: .github/workflows/python-package.yml

@@ -22,10 +22,13 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install black
+        python -m pip install black mypy
     - name: Check code formatting
       run: |
         black --check .
+    - name: Check static typing
+      run: |
+        mypy --strict diffplus/
     - name: Run unit tests
       run: |
         python -m unittest tests/test.py

Diff for: diffplus/incremental_diff.py

@@ -1,5 +1,9 @@
-from .indented_config import IndentedConfig
+from .indented_config import IndentedConfig, IndentedConfigDict
 from re import sub, M
+from typing import Dict
+
+# Recursive type alias
+IncrementalDiffDict = Dict[str, "IncrementalDiffDict"]
 
 
 class IncrementalDiff:
@@ -18,8 +22,12 @@ class IncrementalDiff:
     # Coloring is useful to better visualize the changes in the diff.
     #
     def __init__(
-        self, a: IndentedConfig, b: IndentedConfig, merge=False, colored=False
-    ):
+        self,
+        a: IndentedConfig,
+        b: IndentedConfig,
+        merge: bool = False,
+        colored: bool = False,
+    ) -> None:
         self.a = a
         self.b = b
         self.merge = merge
@@ -28,13 +36,13 @@ def __init__(
     #
     # Returns the incremental diff as a dict.
     #
-    def to_dict(self):
+    def to_dict(self) -> IncrementalDiffDict:
         return IncrementalDiff._to_dict(self.a.to_dict(), self.b.to_dict(), self.merge)
 
     #
     # Returns the incremental diff as an str.
     #
-    def __str__(self):
+    def __str__(self) -> str:
         str_ = IncrementalDiff._to_str(self.to_dict(), indent_char=self.a.indent_char)
         if self.colored:
             str_ = sub(
@@ -47,8 +55,10 @@ def __str__(self):
     # New items from A are prepended by "+" to tell them from existing ones from B.
     #
     @staticmethod
-    def _to_dict(a, b, merge=False):
-        new_items = {}
+    def _to_dict(
+        a: IndentedConfigDict, b: IndentedConfigDict, merge: bool = False
+    ) -> IncrementalDiffDict:
+        new_items: IncrementalDiffDict = {}
 
         for item in a.keys():
             if item not in b.keys():
@@ -71,7 +81,12 @@ def _to_dict(a, b, merge=False):
     # It is pretty as it indents lines and adds a "+" in front of new ones.
     #
     @staticmethod
-    def _to_str(incrdiff, indent_char=" ", indent_level=0, is_new=False):
+    def _to_str(
+        incrdiff: IncrementalDiffDict,
+        indent_char: str = " ",
+        indent_level: int = 0,
+        is_new: bool = False,
+    ) -> str:
         str_ = ""
 
         for item in incrdiff:

Diff for: diffplus/indented_config.py

@@ -1,3 +1,9 @@
+from typing import Dict, List
+
+# Recursive type alias
+IndentedConfigDict = Dict[str, "IndentedConfigDict"]
+
+
 class IndentedConfig:
     #
     # Initializes a given config:
@@ -6,11 +12,17 @@ class IndentedConfig:
     #
     # The config may be sanitized at init via the "sanitize" parameter.
     #
-    def __init__(self, config: str, indent_char=" ", comment_char="#", sanitize=False):
+    def __init__(
+        self,
+        config: str,
+        indent_char: str = " ",
+        comment_char: str = "#",
+        sanitize: bool = False,
+    ) -> None:
         if not len(indent_char) == 1:
-            raise ValueError(f'"indent_char" must be a char, not an str')
+            raise ValueError(f'"indent_char" must be a char')
         if not len(comment_char) == 1:
-            raise ValueError(f'"comment_char" must be a char, not an str')
+            raise ValueError(f'"comment_char" must be a char')
         self.config = config
         self.indent_char = indent_char
         self.comment_char = comment_char
@@ -24,8 +36,8 @@ def __init__(self, config: str, indent_char=" ", comment_char="#", sanitize=Fals
     #
     # A KeyError may be raised if the config is not correctly indented.
     #
-    def to_dict(self):
-        tree = {}
+    def to_dict(self) -> IndentedConfigDict:
+        tree: IndentedConfigDict = {}
         last_parent = {0: tree}  # last parents encountered by indent level
 
         for line in self.config.splitlines():
@@ -42,8 +54,8 @@ def to_dict(self):
     #   - ignore blank lines and comments
     #   - fix lines not correctly indented
     #
-    def sanitize(self):
-        sanitized_indented_config = []
+    def sanitize(self) -> None:
+        sanitized_indented_config: List[str] = []
         max_indent_level = 0
 
         for line in self.config.splitlines():
@@ -73,5 +85,5 @@ def sanitize(self):
     #
     # Returns the indented config as an str.
     #
-    def __str__(self):
+    def __str__(self) -> str:
         return self.config