Merge 4daa79c1d6 into de52317c58

.github/workflows/test.yml

@@ -33,3 +33,5 @@ jobs:
         run: |
           poetry install
           poetry run python -m unittest -v tests/*.py
+      - name: Run mypy
+        run: poetry run mypy

diagrams/__init__.py

@@ -1,49 +1,44 @@
-import contextvars
 import os
 import uuid
+from contextvars import ContextVar
 from pathlib import Path
-from typing import Dict, List, Optional, Union
+from typing import Any, AnyStr, cast, Dict, List, Mapping, Optional, Tuple, Type, Union
+from types import TracebackType
 
-from graphviz import Digraph
+from graphviz import Digraph  # type: ignore[import]
 
 # Global contexts for a diagrams and a cluster.
 #
 # These global contexts are for letting the clusters and nodes know
 # where context they are belong to. So the all clusters and nodes does
 # not need to specify the current diagrams or cluster via parameters.
-__diagram = contextvars.ContextVar("diagrams")
-__cluster = contextvars.ContextVar("cluster")
+__diagram: ContextVar[Optional["Diagram"]] = ContextVar("diagrams")
+__cluster: ContextVar[Optional["Cluster"]] = ContextVar("cluster")
 
 
-def getdiagram() -> "Diagram":
-    try:
-        return __diagram.get()
-    except LookupError:
-        return None
+def getdiagram() -> Optional["Diagram"]:
+    return __diagram.get(None)
 
 
-def setdiagram(diagram: "Diagram"):
+def setdiagram(diagram: Optional["Diagram"]) -> None:
     __diagram.set(diagram)
 
 
-def getcluster() -> "Cluster":
-    try:
-        return __cluster.get()
-    except LookupError:
-        return None
+def getcluster() -> Optional["Cluster"]:
+    return __cluster.get(None)
 
 
-def setcluster(cluster: "Cluster"):
+def setcluster(cluster: Optional["Cluster"]) -> None:
     __cluster.set(cluster)
 
 
 class Diagram:
-    __directions = ("TB", "BT", "LR", "RL")
-    __curvestyles = ("ortho", "curved")
-    __outformats = ("png", "jpg", "svg", "pdf", "dot")
+    __directions: Tuple[str, ...] = ("TB", "BT", "LR", "RL")
+    __curvestyles: Tuple[str, ...] = ("ortho", "curved")
+    __outformats: Tuple[str, ...] = ("png", "jpg", "svg", "pdf", "dot")
 
     # fmt: off
-    _default_graph_attrs = {
+    _default_graph_attrs: Mapping[str, str] = {
         "pad": "2.0",
         "splines": "ortho",
         "nodesep": "0.60",
@@ -52,7 +47,7 @@ class Diagram:
         "fontsize": "15",
         "fontcolor": "#2D3436",
     }
-    _default_node_attrs = {
+    _default_node_attrs: Mapping[str, str] = {
         "shape": "box",
         "style": "rounded",
         "fixedsize": "true",
@@ -68,7 +63,7 @@ class Diagram:
         "fontsize": "13",
         "fontcolor": "#2D3436",
     }
-    _default_edge_attrs = {
+    _default_edge_attrs: Mapping[str, str] = {
         "color": "#7B8894",
     }
 
@@ -82,13 +77,13 @@ class Diagram:
         filename: str = "",
         direction: str = "LR",
         curvestyle: str = "ortho",
-        outformat: str = "png",
+        outformat: Union[List[str], str] = "png",
         autolabel: bool = False,
         show: bool = True,
         strict: bool = False,
-        graph_attr: Optional[dict] = None,
-        node_attr: Optional[dict] = None,
-        edge_attr: Optional[dict] = None,
+        graph_attr: Optional[Mapping[str, Any]] = None,
+        node_attr: Optional[Mapping[str, Any]] = None,
+        edge_attr: Optional[Mapping[str, Any]] = None,
     ):
         """Diagram represents a global diagrams context.
 
@@ -116,8 +111,8 @@ class Diagram:
             filename = "diagrams_image"
         elif not filename:
             filename = "_".join(self.name.split()).lower()
-        self.filename = filename
-        self.dot = Digraph(self.name, filename=self.filename, strict=strict)
+        self.filename: str = filename
+        self.dot: Digraph = Digraph(self.name, filename=self.filename, strict=strict)
 
         # Set attributes.
         for k, v in self._default_graph_attrs.items():
@@ -143,7 +138,7 @@ class Diagram:
         else:
             if not self._validate_outformat(outformat):
                 raise ValueError(f'"{outformat}" is not a valid output format')
-        self.outformat = outformat
+        self.outformat: Union[List[str], str] = outformat
 
         # Merge passed in attributes
         self.dot.graph_attr.update(graph_attr)
@@ -156,18 +151,23 @@ class Diagram:
     def __str__(self) -> str:
         return str(self.dot)
 
-    def __enter__(self):
+    def __enter__(self) -> "Diagram":
         setdiagram(self)
         return self
 
-    def __exit__(self, exc_type, exc_value, traceback):
+    def __exit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_value: Optional[BaseException],
+        traceback: Optional[TracebackType],
+    ) -> None:
         self.render()
         # Remove the graphviz file leaving only the image.
         os.remove(self.filename)
         setdiagram(None)
 
-    def _repr_png_(self):
-        return self.dot.pipe(format="png")
+    def _repr_png(self) -> AnyStr:
+        return cast(AnyStr, self.dot.pipe(format="png"))
 
     def _validate_direction(self, direction: str) -> bool:
         return direction.upper() in self.__directions
@@ -178,7 +178,7 @@ class Diagram:
     def _validate_outformat(self, outformat: str) -> bool:
         return outformat.lower() in self.__outformats
 
-    def node(self, nodeid: str, label: str, **attrs) -> None:
+    def node(self, nodeid: str, label: str, **attrs: Dict[Any, Any]) -> None:
         """Create a new node."""
         self.dot.node(nodeid, label=label, **attrs)
 
@@ -199,11 +199,11 @@ class Diagram:
 
 
 class Cluster:
-    __directions = ("TB", "BT", "LR", "RL")
-    __bgcolors = ("#E5F5FD", "#EBF3E7", "#ECE8F6", "#FDF7E3")
+    __directions: Tuple[str, ...] = ("TB", "BT", "LR", "RL")
+    __bgcolors: Tuple[str, ...] = ("#E5F5FD", "#EBF3E7", "#ECE8F6", "#FDF7E3")
 
     # fmt: off
-    _default_graph_attrs = {
+    _default_graph_attrs: Mapping[str, str] = {
         "shape": "box",
         "style": "rounded",
         "labeljust": "l",
@@ -221,7 +221,7 @@ class Cluster:
         self,
         label: str = "cluster",
         direction: str = "LR",
-        graph_attr: Optional[dict] = None,
+        graph_attr: Optional[Mapping[str, Any]] = None,
     ):
         """Cluster represents a cluster context.
 
@@ -231,10 +231,10 @@ class Cluster:
         """
         if graph_attr is None:
             graph_attr = {}
-        self.label = label
-        self.name = "cluster_" + self.label
+        self.label: str = label
+        self.name: str = f"cluster_{self.label}"
 
-        self.dot = Digraph(self.name)
+        self.dot: Digraph = Digraph(self.name)
 
         # Set attributes.
         for k, v in self._default_graph_attrs.items():
@@ -246,24 +246,30 @@ class Cluster:
         self.dot.graph_attr["rankdir"] = direction
 
         # Node must be belong to a diagrams.
-        self._diagram = getdiagram()
-        if self._diagram is None:
+        diagram = getdiagram()
+        if diagram is None:
             raise EnvironmentError("Global diagrams context not set up")
-        self._parent = getcluster()
+        self._diagram: Diagram = diagram
+        self._parent: Optional["Cluster"] = getcluster()
 
         # Set cluster depth for distinguishing the background color
-        self.depth = self._parent.depth + 1 if self._parent else 0
+        self.depth: int = self._parent.depth + 1 if self._parent else 0
         coloridx = self.depth % len(self.__bgcolors)
         self.dot.graph_attr["bgcolor"] = self.__bgcolors[coloridx]
 
         # Merge passed in attributes
         self.dot.graph_attr.update(graph_attr)
 
-    def __enter__(self):
+    def __enter__(self) -> "Cluster":
         setcluster(self)
         return self
 
-    def __exit__(self, exc_type, exc_value, traceback):
+    def __exit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_value: Optional[BaseException],
+        traceback: Optional[TracebackType],
+    ) -> None:
         if self._parent:
             self._parent.subgraph(self.dot)
         else:
@@ -273,7 +279,7 @@ class Cluster:
     def _validate_direction(self, direction: str) -> bool:
         return direction.upper() in self.__directions
 
-    def node(self, nodeid: str, label: str, **attrs) -> None:
+    def node(self, nodeid: str, label: str, **attrs: Dict[Any, Any]) -> None:
         """Create a new node in the cluster."""
         self.dot.node(nodeid, label=label, **attrs)
 
@@ -284,32 +290,33 @@ class Cluster:
 class Node:
     """Node represents a node for a specific backend service."""
 
-    _provider = None
-    _type = None
+    _provider: Optional[str] = None
+    _type: Optional[str] = None
 
-    _icon_dir = None
-    _icon = None
+    _icon_dir: Optional[str] = None
+    _icon: Optional[str] = None
 
-    _height = 1.9
+    _height: float = 1.9
 
-    def __init__(self, label: str = "", *, nodeid: str = None, **attrs: Dict):
+    def __init__(self, label: str = "", *, nodeid: Optional[str] = None, **attrs: Dict[Any, Any]):
         """Node represents a system component.
 
         :param label: Node label.
         """
         # Generates an ID for identifying a node, unless specified
-        self._id = nodeid or self._rand_id()
-        self.label = label
+        self._id: str = nodeid or self._rand_id()
+        self.label: str = label
 
         # Node must be belong to a diagrams.
-        self._diagram = getdiagram()
-        if self._diagram is None:
+        diagram = getdiagram()
+        if diagram is None:
             raise EnvironmentError("Global diagrams context not set up")
+        self._diagram: Diagram = diagram
 
         if self._diagram.autolabel:
             prefix = self.__class__.__name__
             if self.label:
-                self.label = prefix + "\n" + self.label
+                self.label = f"{prefix}\n{self.label}"
             else:
                 self.label = prefix
 
@@ -318,16 +325,17 @@ class Node:
         # that label being spanned between icon image and white space.
         # Increase the height by the number of new lines included in the label.
         padding = 0.4 * (self.label.count('\n'))
-        self._attrs = {
+        icon = self._load_icon()
+        self._attrs: Dict[str, Any] = {
             "shape": "none",
             "height": str(self._height + padding),
-            "image": self._load_icon(),
-        } if self._icon else {}
+            "image": icon,
+        } if icon is not None else {}
 
         # fmt: on
         self._attrs.update(attrs)
 
-        self._cluster = getcluster()
+        self._cluster: Optional[Cluster] = getcluster()
 
         # If a node is in the cluster context, add it to cluster.
         if self._cluster:
@@ -335,23 +343,22 @@ class Node:
         else:
             self._diagram.node(self._id, self.label, **self._attrs)
 
-    def __repr__(self):
-        _name = self.__class__.__name__
-        return f"<{self._provider}.{self._type}.{_name}>"
+    def __repr__(self) -> str:
+        name = self.__class__.__name__
+        return f"<{self._provider}.{self._type}.{name}>"
 
-    def __sub__(self, other: Union["Node", List["Node"], "Edge"]):
+    def __sub__(self, other: Union["Node", List["Node"], "Edge"]) -> Union["Node", List["Node"], "Edge"]:
         """Implement Self - Node, Self - [Nodes] and Self - Edge."""
         if isinstance(other, list):
             for node in other:
                 self.connect(node, Edge(self))
             return other
-        elif isinstance(other, Node):
+        if isinstance(other, Node):
             return self.connect(other, Edge(self))
-        else:
-            other.node = self
-            return other
+        other.node = self
+        return other
 
-    def __rsub__(self, other: Union[List["Node"], List["Edge"]]):
+    def __rsub__(self, other: Union[List["Node"], List["Edge"]]) -> "Node":
         """Called for [Nodes] and [Edges] - Self because list don't have __sub__ operators."""
         for o in other:
             if isinstance(o, Edge):
@@ -360,32 +367,30 @@ class Node:
                 o.connect(self, Edge(self))
         return self
 
-    def __rshift__(self, other: Union["Node", List["Node"], "Edge"]):
+    def __rshift__(self, other: Union["Node", List["Node"], "Edge"]) -> Union["Node", List["Node"], "Edge"]:
         """Implements Self >> Node, Self >> [Nodes] and Self Edge."""
         if isinstance(other, list):
             for node in other:
                 self.connect(node, Edge(self, forward=True))
             return other
-        elif isinstance(other, Node):
+        if isinstance(other, Node):
             return self.connect(other, Edge(self, forward=True))
-        else:
-            other.forward = True
-            other.node = self
-            return other
+        other.forward = True
+        other.node = self
+        return other
 
-    def __lshift__(self, other: Union["Node", List["Node"], "Edge"]):
+    def __lshift__(self, other: Union["Node", List["Node"], "Edge"]) -> Union["Node", List["Node"], "Edge"]:
         """Implements Self << Node, Self << [Nodes] and Self << Edge."""
         if isinstance(other, list):
             for node in other:
                 self.connect(node, Edge(self, reverse=True))
             return other
-        elif isinstance(other, Node):
+        if isinstance(other, Node):
             return self.connect(other, Edge(self, reverse=True))
-        else:
-            other.reverse = True
-            return other.connect(self)
+        other.reverse = True
+        return other.connect(self)
 
-    def __rrshift__(self, other: Union[List["Node"], List["Edge"]]):
+    def __rrshift__(self, other: Union[List["Node"], List["Edge"]]) -> "Node":
         """Called for [Nodes] and [Edges] >> Self because list don't have __rshift__ operators."""
         for o in other:
             if isinstance(o, Edge):
@@ -395,7 +400,7 @@ class Node:
                 o.connect(self, Edge(self, forward=True))
         return self
 
-    def __rlshift__(self, other: Union[List["Node"], List["Edge"]]):
+    def __rlshift__(self, other: Union[List["Node"], List["Edge"]]) -> "Node":
         """Called for [Nodes] << Self because list of Nodes don't have __lshift__ operators."""
         for o in other:
             if isinstance(o, Edge):
@@ -406,11 +411,11 @@ class Node:
         return self
 
     @property
-    def nodeid(self):
+    def nodeid(self) -> str:
         return self._id
 
     # TODO: option for adding flow description to the connection edge
-    def connect(self, node: "Node", edge: "Edge"):
+    def connect(self, node: "Node", edge: "Edge") -> "Node":
         """Connect to other node.
 
         :param node: Other node instance.
@@ -426,18 +431,19 @@ class Node:
         return node
 
     @staticmethod
-    def _rand_id():
+    def _rand_id() -> str:
         return uuid.uuid4().hex
 
-    def _load_icon(self):
-        basedir = Path(os.path.abspath(os.path.dirname(__file__)))
-        return os.path.join(basedir.parent, self._icon_dir, self._icon)
+    def _load_icon(self) -> Optional[str]:
+        if self._icon_dir is None or self._icon is None:
+            return None
+        return str(Path(__file__).parent / self._icon_dir / self._icon)
 
 
 class Edge:
     """Edge represents an edge between two nodes."""
 
-    _default_edge_attrs = {
+    _default_edge_attrs: Mapping[str, str] = {
         "fontcolor": "#2D3436",
         "fontname": "Sans-Serif",
         "fontsize": "13",
@@ -445,13 +451,13 @@ class Edge:
 
     def __init__(
         self,
-        node: "Node" = None,
+        node: Optional["Node"] = None,
         forward: bool = False,
         reverse: bool = False,
         label: str = "",
         color: str = "",
         style: str = "",
-        **attrs: Dict,
+        **attrs: Dict[Any, Any],
     ):
         """Edge represents an edge between two nodes.
 
@@ -466,11 +472,11 @@ class Edge:
         if node is not None:
             assert isinstance(node, Node)
 
-        self.node = node
-        self.forward = forward
-        self.reverse = reverse
+        self.node: Optional[Node] = node
+        self.forward: bool = forward
+        self.reverse: bool = reverse
 
-        self._attrs = {}
+        self._attrs: Dict[str, Any] = {}
 
         # Set attributes.
         for k, v in self._default_edge_attrs.items():
@@ -486,7 +492,7 @@ class Edge:
             self._attrs["style"] = style
         self._attrs.update(attrs)
 
-    def __sub__(self, other: Union["Node", "Edge", List["Node"]]):
+    def __sub__(self, other: Union["Node", "Edge", List["Node"]]) -> Union["Node", "Edge", List["Node"]]:
         """Implement Self - Node or Edge and Self - [Nodes]"""
         return self.connect(other)
 
@@ -494,12 +500,12 @@ class Edge:
         """Called for [Nodes] or [Edges] - Self because list don't have __sub__ operators."""
         return self.append(other)
 
-    def __rshift__(self, other: Union["Node", "Edge", List["Node"]]):
+    def __rshift__(self, other: Union["Node", "Edge", List["Node"]]) -> Union["Node", "Edge", List["Node"]]:
         """Implements Self >> Node or Edge and Self >> [Nodes]."""
         self.forward = True
         return self.connect(other)
 
-    def __lshift__(self, other: Union["Node", "Edge", List["Node"]]):
+    def __lshift__(self, other: Union["Node", "Edge", List["Node"]]) -> Union["Node", "Edge", List["Node"]]:
         """Implements Self << Node or Edge and Self << [Nodes]."""
         self.reverse = True
         return self.connect(other)
@@ -512,35 +518,36 @@ class Edge:
         """Called for [Nodes] or [Edges] << Self because list of Edges don't have __lshift__ operators."""
         return self.append(other, reverse=True)
 
-    def append(self, other: Union[List["Node"], List["Edge"]], forward=None, reverse=None) -> List["Edge"]:
+    def append(
+        self, other: Union[List["Node"], List["Edge"]], forward: Optional[bool] = None, reverse: Optional[bool] = None
+    ) -> List["Edge"]:
         result = []
         for o in other:
             if isinstance(o, Edge):
                 o.forward = forward if forward else o.forward
-                o.reverse = forward if forward else o.reverse
+                o.reverse = reverse if reverse else o.reverse
                 self._attrs = o.attrs.copy()
                 result.append(o)
             else:
-                result.append(Edge(o, forward=forward, reverse=reverse, **self._attrs))
+                result.append(Edge(o, forward=bool(forward), reverse=bool(reverse), **self._attrs))
         return result
 
-    def connect(self, other: Union["Node", "Edge", List["Node"]]):
+    def connect(self, other: Union["Node", "Edge", List["Node"]]) -> Union["Node", "Edge", List["Node"]]:
         if isinstance(other, list):
-            for node in other:
-                self.node.connect(node, self)
+            if self.node is not None:
+                for node in other:
+                    self.node.connect(node, self)
             return other
-        elif isinstance(other, Edge):
+        if isinstance(other, Edge):
             self._attrs = other._attrs.copy()
             return self
-        else:
-            if self.node is not None:
-                return self.node.connect(other, self)
-            else:
-                self.node = other
-                return self
+        if self.node is not None:
+            return self.node.connect(other, self)
+        self.node = other
+        return self
 
     @property
-    def attrs(self) -> Dict:
+    def attrs(self) -> Dict[str, Any]:
         if self.forward and self.reverse:
             direction = "both"
         elif self.forward:
@@ -552,4 +559,4 @@ class Edge:
         return {**self._attrs, "dir": direction}
 
 
-Group = Cluster
+Group: Type[Cluster] = Cluster

diagrams/aws/general.py

@@ -102,8 +102,3 @@ class User(_General):
 
 class Users(_General):
     _icon = "users.png"
-
-
-# Aliases
-
-OfficeBuilding = GenericOfficeBuilding

diagrams/c4/__init__.py

@@ -3,10 +3,12 @@ A set of nodes and edges to visualize software architecture using the C4 model.
 """
 import html
 import textwrap
+from typing import Any, Dict
+
 from diagrams import Cluster, Node, Edge
 
 
-def _format_node_label(name, key, description):
+def _format_node_label(name: str, key: str, description: str) -> str:
     """Create a graphviz label string for a C4 node"""
     title = f'<font point-size="12"><b>{html.escape(name)}</b></font><br/>'
     subtitle = f'<font point-size="9">[{html.escape(key)}]<br/></font>' if key else ""
@@ -14,7 +16,7 @@ def _format_node_label(name, key, description):
     return f"<{title}{subtitle}{text}>"
 
 
-def _format_description(description):
+def _format_description(description: str) -> str:
     """
     Formats the description string so it fits into the C4 nodes.
 
@@ -29,7 +31,7 @@ def _format_description(description):
     return "<br/>".join(lines)
 
 
-def _format_edge_label(description):
+def _format_edge_label(description: str) -> str:
     """Create a graphviz label string for a C4 edge"""
     wrapper = textwrap.TextWrapper(width=24, max_lines=3)
     lines = [html.escape(line) for line in wrapper.wrap(description)]
@@ -37,9 +39,9 @@ def _format_edge_label(description):
     return f'<<font point-size="10">{text}</font>>'
 
 
-def C4Node(name, technology="", description="", type="Container", **kwargs):
+def C4Node(name: str, technology: str = "", description: str = "", type: str = "Container", **kwargs: Dict[str, Any]) -> Node:
     key = f"{type}: {technology}" if technology else type
-    node_attributes = {
+    node_attributes: Dict[str, Any] = {
         "label": _format_node_label(name, key, description),
         "labelloc": "c",
         "shape": "rect",
@@ -57,8 +59,8 @@ def C4Node(name, technology="", description="", type="Container", **kwargs):
     return Node(**node_attributes)
 
 
-def Container(name, technology="", description="", **kwargs):
-    container_attributes = {
+def Container(name: str, technology: str = "", description: str = "", **kwargs: Dict[str, Any]) -> Node:
+    container_attributes: Dict[str, Any] = {
         "name": name,
         "technology": technology,
         "description": description,
@@ -68,8 +70,8 @@ def Container(name, technology="", description="", **kwargs):
     return C4Node(**container_attributes)
 
 
-def Database(name, technology="", description="", **kwargs):
-    database_attributes = {
+def Database(name: str, technology: str = "", description: str = "", **kwargs: Dict[str, Any]) -> Node:
+    database_attributes: Dict[str, Any] = {
         "name": name,
         "technology": technology,
         "description": description,
@@ -81,8 +83,8 @@ def Database(name, technology="", description="", **kwargs):
     return C4Node(**database_attributes)
 
 
-def System(name, description="", external=False, **kwargs):
-    system_attributes = {
+def System(name: str, description: str = "", external: bool = False, **kwargs: Dict[str, Any]) -> Node:
+    system_attributes: Dict[str, Any] = {
         "name": name,
         "description": description,
         "type": "External System" if external else "System",
@@ -92,8 +94,8 @@ def System(name, description="", external=False, **kwargs):
     return C4Node(**system_attributes)
 
 
-def Person(name, description="", external=False, **kwargs):
-    person_attributes = {
+def Person(name: str, description: str = "", external: bool = False, **kwargs: Dict[str, Any]) -> Node:
+    person_attributes: Dict[str, Any] = {
         "name": name,
         "description": description,
         "type": "External Person" if external else "Person",
@@ -104,8 +106,8 @@ def Person(name, description="", external=False, **kwargs):
     return C4Node(**person_attributes)
 
 
-def SystemBoundary(name, **kwargs):
-    graph_attributes = {
+def SystemBoundary(name: str, **kwargs: Dict[str, Any]) -> Cluster:
+    graph_attributes: Dict[str, Any] = {
         "label": html.escape(name),
         "bgcolor": "white",
         "margin": "16",
@@ -115,8 +117,8 @@ def SystemBoundary(name, **kwargs):
     return Cluster(name, graph_attr=graph_attributes)
 
 
-def Relationship(label="", **kwargs):
-    edge_attributes = {
+def Relationship(label: str = "", **kwargs: Dict[str, Any]) -> Edge:
+    edge_attributes: Dict[str, Any] = {
         "style": "dashed",
         "color": "gray60",
         "label": _format_edge_label(label) if label else "",

diagrams/custom/__init__.py

@@ -2,6 +2,8 @@
 Custom provides the possibility of load an image to be presented as a node.
 """
 
+from typing import Any, Dict, Optional, override
+
 from diagrams import Node
 
 
@@ -12,9 +14,11 @@ class Custom(Node):
 
     fontcolor = "#ffffff"
 
-    def _load_icon(self):
+    @override
+    def _load_icon(self) -> Optional[str]:
         return self._icon
 
-    def __init__(self, label, icon_path, *args, **kwargs):
-        self._icon = icon_path
-        super().__init__(label, *args, **kwargs)
+    @override
+    def __init__(self, label: str, icon_path: Optional[str], *, nodeid: Optional[str] = None, **attrs: Dict[Any, Any]):
+        self._icon: Optional[str] = icon_path
+        super().__init__(label, nodeid=nodeid, **attrs)

poetry.lock

@@ -1,10 +1,9 @@
-# This file is automatically @generated by Poetry and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.7.1 and should not be changed by hand.
 
 [[package]]
 name = "astroid"
 version = "2.9.0"
 description = "An abstract syntax tree for Python with inference support."
-category = "dev"
 optional = false
 python-versions = "~=3.6"
 files = [
@@ -23,7 +22,6 @@ wrapt = ">=1.11,<1.14"
 name = "black"
 version = "22.12.0"
 description = "The uncompromising code formatter."
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -60,7 +58,6 @@ uvloop = ["uvloop (>=0.15.2)"]
 name = "click"
 version = "8.1.3"
 description = "Composable command line interface toolkit"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -76,7 +73,6 @@ importlib-metadata = {version = "*", markers = "python_version < \"3.8\""}
 name = "colorama"
 version = "0.4.3"
 description = "Cross-platform colored terminal text."
-category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
 files = [
@@ -88,7 +84,6 @@ files = [
 name = "exceptiongroup"
 version = "1.1.0"
 description = "Backport of PEP 654 (exception groups)"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -103,7 +98,6 @@ test = ["pytest (>=6)"]
 name = "graphviz"
 version = "0.20.1"
 description = "Simple Python interface for Graphviz"
-category = "main"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -120,7 +114,6 @@ test = ["coverage", "mock (>=4)", "pytest (>=7)", "pytest-cov", "pytest-mock (>=
 name = "importlib-metadata"
 version = "1.5.0"
 description = "Read metadata from Python packages"
-category = "dev"
 optional = false
 python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,>=2.7"
 files = [
@@ -139,7 +132,6 @@ testing = ["importlib-resources", "packaging"]
 name = "iniconfig"
 version = "1.1.1"
 description = "iniconfig: brain-dead simple config-ini parsing"
-category = "dev"
 optional = false
 python-versions = "*"
 files = [
@@ -151,7 +143,6 @@ files = [
 name = "isort"
 version = "4.3.21"
 description = "A Python utility / library to sort Python imports."
-category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 files = [
@@ -169,7 +160,6 @@ xdg-home = ["appdirs (>=1.4.0)"]
 name = "jinja2"
 version = "3.1.2"
 description = "A very fast and expressive template engine."
-category = "main"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -187,7 +177,6 @@ i18n = ["Babel (>=2.7)"]
 name = "lazy-object-proxy"
 version = "1.4.3"
 description = "A fast and thorough lazy object proxy."
-category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 files = [
@@ -218,7 +207,6 @@ files = [
 name = "markupsafe"
 version = "2.0.1"
 description = "Safely add untrusted strings to HTML/XML markup."
-category = "main"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -297,7 +285,6 @@ files = [
 name = "mccabe"
 version = "0.6.1"
 description = "McCabe checker, plugin for flake8"
-category = "dev"
 optional = false
 python-versions = "*"
 files = [
@@ -306,22 +293,67 @@ files = [
 ]
 
 [[package]]
+name = "mypy"
+version = "1.4.1"
+description = "Optional static typing for Python"
+optional = false
+python-versions = ">=3.7"
+files = [
+    {file = "mypy-1.4.1-cp310-cp310-macosx_10_9_x86_64.whl", hash = "sha256:566e72b0cd6598503e48ea610e0052d1b8168e60a46e0bfd34b3acf2d57f96a8"},
+    {file = "mypy-1.4.1-cp310-cp310-macosx_11_0_arm64.whl", hash = "sha256:ca637024ca67ab24a7fd6f65d280572c3794665eaf5edcc7e90a866544076878"},
+    {file = "mypy-1.4.1-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:0dde1d180cd84f0624c5dcaaa89c89775550a675aff96b5848de78fb11adabcd"},
+    {file = "mypy-1.4.1-cp310-cp310-musllinux_1_1_x86_64.whl", hash = "sha256:8c4d8e89aa7de683e2056a581ce63c46a0c41e31bd2b6d34144e2c80f5ea53dc"},
+    {file = "mypy-1.4.1-cp310-cp310-win_amd64.whl", hash = "sha256:bfdca17c36ae01a21274a3c387a63aa1aafe72bff976522886869ef131b937f1"},
+    {file = "mypy-1.4.1-cp311-cp311-macosx_10_9_x86_64.whl", hash = "sha256:7549fbf655e5825d787bbc9ecf6028731973f78088fbca3a1f4145c39ef09462"},
+    {file = "mypy-1.4.1-cp311-cp311-macosx_11_0_arm64.whl", hash = "sha256:98324ec3ecf12296e6422939e54763faedbfcc502ea4a4c38502082711867258"},
+    {file = "mypy-1.4.1-cp311-cp311-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:141dedfdbfe8a04142881ff30ce6e6653c9685b354876b12e4fe6c78598b45e2"},
+    {file = "mypy-1.4.1-cp311-cp311-musllinux_1_1_x86_64.whl", hash = "sha256:8207b7105829eca6f3d774f64a904190bb2231de91b8b186d21ffd98005f14a7"},
+    {file = "mypy-1.4.1-cp311-cp311-win_amd64.whl", hash = "sha256:16f0db5b641ba159eff72cff08edc3875f2b62b2fa2bc24f68c1e7a4e8232d01"},
+    {file = "mypy-1.4.1-cp37-cp37m-macosx_10_9_x86_64.whl", hash = "sha256:470c969bb3f9a9efcedbadcd19a74ffb34a25f8e6b0e02dae7c0e71f8372f97b"},
+    {file = "mypy-1.4.1-cp37-cp37m-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:e5952d2d18b79f7dc25e62e014fe5a23eb1a3d2bc66318df8988a01b1a037c5b"},
+    {file = "mypy-1.4.1-cp37-cp37m-musllinux_1_1_x86_64.whl", hash = "sha256:190b6bab0302cec4e9e6767d3eb66085aef2a1cc98fe04936d8a42ed2ba77bb7"},
+    {file = "mypy-1.4.1-cp37-cp37m-win_amd64.whl", hash = "sha256:9d40652cc4fe33871ad3338581dca3297ff5f2213d0df345bcfbde5162abf0c9"},
+    {file = "mypy-1.4.1-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:01fd2e9f85622d981fd9063bfaef1aed6e336eaacca00892cd2d82801ab7c042"},
+    {file = "mypy-1.4.1-cp38-cp38-macosx_11_0_arm64.whl", hash = "sha256:2460a58faeea905aeb1b9b36f5065f2dc9a9c6e4c992a6499a2360c6c74ceca3"},
+    {file = "mypy-1.4.1-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:a2746d69a8196698146a3dbe29104f9eb6a2a4d8a27878d92169a6c0b74435b6"},
+    {file = "mypy-1.4.1-cp38-cp38-musllinux_1_1_x86_64.whl", hash = "sha256:ae704dcfaa180ff7c4cfbad23e74321a2b774f92ca77fd94ce1049175a21c97f"},
+    {file = "mypy-1.4.1-cp38-cp38-win_amd64.whl", hash = "sha256:43d24f6437925ce50139a310a64b2ab048cb2d3694c84c71c3f2a1626d8101dc"},
+    {file = "mypy-1.4.1-cp39-cp39-macosx_10_9_x86_64.whl", hash = "sha256:c482e1246726616088532b5e964e39765b6d1520791348e6c9dc3af25b233828"},
+    {file = "mypy-1.4.1-cp39-cp39-macosx_11_0_arm64.whl", hash = "sha256:43b592511672017f5b1a483527fd2684347fdffc041c9ef53428c8dc530f79a3"},
+    {file = "mypy-1.4.1-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:34a9239d5b3502c17f07fd7c0b2ae6b7dd7d7f6af35fbb5072c6208e76295816"},
+    {file = "mypy-1.4.1-cp39-cp39-musllinux_1_1_x86_64.whl", hash = "sha256:5703097c4936bbb9e9bce41478c8d08edd2865e177dc4c52be759f81ee4dd26c"},
+    {file = "mypy-1.4.1-cp39-cp39-win_amd64.whl", hash = "sha256:e02d700ec8d9b1859790c0475df4e4092c7bf3272a4fd2c9f33d87fac4427b8f"},
+    {file = "mypy-1.4.1-py3-none-any.whl", hash = "sha256:45d32cec14e7b97af848bddd97d85ea4f0db4d5a149ed9676caa4eb2f7402bb4"},
+    {file = "mypy-1.4.1.tar.gz", hash = "sha256:9bbcd9ab8ea1f2e1c8031c21445b511442cc45c89951e49bbf852cbb70755b1b"},
+]
+
+[package.dependencies]
+mypy-extensions = ">=1.0.0"
+tomli = {version = ">=1.1.0", markers = "python_version < \"3.11\""}
+typed-ast = {version = ">=1.4.0,<2", markers = "python_version < \"3.8\""}
+typing-extensions = ">=4.1.0"
+
+[package.extras]
+dmypy = ["psutil (>=4.0)"]
+install-types = ["pip"]
+python2 = ["typed-ast (>=1.4.0,<2)"]
+reports = ["lxml"]
+
+[[package]]
 name = "mypy-extensions"
-version = "0.4.3"
-description = "Experimental type system extensions for programs checked with the mypy typechecker."
-category = "dev"
+version = "1.0.0"
+description = "Type system extensions for programs checked with the mypy type checker."
 optional = false
-python-versions = "*"
+python-versions = ">=3.5"
 files = [
-    {file = "mypy_extensions-0.4.3-py2.py3-none-any.whl", hash = "sha256:090fedd75945a69ae91ce1303b5824f428daf5a028d2f6ab8a299250a846f15d"},
-    {file = "mypy_extensions-0.4.3.tar.gz", hash = "sha256:2d82818f5bb3e369420cb3c4060a7970edba416647068eb4c5343488a6c604a8"},
+    {file = "mypy_extensions-1.0.0-py3-none-any.whl", hash = "sha256:4392f6c0eb8a5668a69e23d168ffa70f0be9ccfd32b5cc2d26a34ae5b844552d"},
+    {file = "mypy_extensions-1.0.0.tar.gz", hash = "sha256:75dbf8955dc00442a438fc4d0666508a9a97b6bd41aa2f0ffe9d2f2725af0782"},
 ]
 
 [[package]]
 name = "packaging"
 version = "20.8"
 description = "Core utilities for Python packages"
-category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 files = [
@@ -336,7 +368,6 @@ pyparsing = ">=2.0.2"
 name = "pathspec"
 version = "0.10.1"
 description = "Utility library for gitignore style pattern matching of file paths."
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -348,7 +379,6 @@ files = [
 name = "platformdirs"
 version = "2.4.0"
 description = "A small Python module for determining appropriate platform-specific dirs, e.g. a \"user data dir\"."
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -364,7 +394,6 @@ test = ["appdirs (==1.4.4)", "pytest (>=6)", "pytest-cov (>=2.7)", "pytest-mock
 name = "pluggy"
 version = "0.13.1"
 description = "plugin and hook calling mechanisms for python"
-category = "dev"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 files = [
@@ -382,7 +411,6 @@ dev = ["pre-commit", "tox"]
 name = "pylint"
 version = "2.12.0"
 description = "python code static checker"
-category = "dev"
 optional = false
 python-versions = "~=3.6"
 files = [
@@ -403,7 +431,6 @@ typing-extensions = {version = ">=3.10.0", markers = "python_version < \"3.10\""
 name = "pyparsing"
 version = "2.4.7"
 description = "Python parsing module"
-category = "dev"
 optional = false
 python-versions = ">=2.6, !=3.0.*, !=3.1.*, !=3.2.*"
 files = [
@@ -415,7 +442,6 @@ files = [
 name = "pytest"
 version = "7.3.0"
 description = "pytest: simple powerful testing with Python"
-category = "dev"
 optional = false
 python-versions = ">=3.7"
 files = [
@@ -439,7 +465,6 @@ testing = ["argcomplete", "attrs (>=19.2.0)", "hypothesis (>=3.56)", "mock", "no
 name = "rope"
 version = "0.14.0"
 description = "a python refactoring library..."
-category = "dev"
 optional = false
 python-versions = "*"
 files = [
@@ -452,7 +477,6 @@ files = [
 name = "setuptools"
 version = "59.6.0"
 description = "Easily download, build, install, upgrade, and uninstall Python packages"
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -468,7 +492,6 @@ testing = ["flake8-2020", "jaraco.envs (>=2.2)", "jaraco.path (>=3.2.0)", "mock"
 name = "toml"
 version = "0.10.0"
 description = "Python Library for Tom's Obvious, Minimal Language"
-category = "dev"
 optional = false
 python-versions = "*"
 files = [
@@ -480,7 +503,6 @@ files = [
 name = "tomli"
 version = "1.2.3"
 description = "A lil' TOML parser"
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -492,7 +514,6 @@ files = [
 name = "typed-ast"
 version = "1.5.4"
 description = "a fork of Python 2 and 3 ast modules with type comment support"
-category = "main"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -526,7 +547,6 @@ files = [
 name = "typing-extensions"
 version = "4.1.1"
 description = "Backported and Experimental Type Hints for Python 3.6+"
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -538,7 +558,6 @@ files = [
 name = "wrapt"
 version = "1.11.2"
 description = "Module for decorators, wrappers and monkey patching."
-category = "dev"
 optional = false
 python-versions = "*"
 files = [
@@ -549,7 +568,6 @@ files = [
 name = "zipp"
 version = "3.1.0"
 description = "Backport of pathlib-compatible object wrapper for zip files"
-category = "dev"
 optional = false
 python-versions = ">=3.6"
 files = [
@@ -564,4 +582,4 @@ testing = ["func-timeout", "jaraco.itertools"]
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.7"
-content-hash = "5c2b82d1c8a6a283f63558fc693271f42fdcaeab73616713eb9b38b0b59787fc"
+content-hash = "03625aefdb3d0562b74d70e00eda5ddb3a477a433adc9aa01b351e3cef897403"

pyproject.toml

@@ -21,6 +21,15 @@ pylint = "^2.7"
 rope = "^0.14.0"
 isort = "^4.3"
 black = "^22.12.0"
+mypy = ">=1.4,<1.8"
 
 [tool.black]
 line-length = 120
+
+[tool.mypy]
+files = "diagrams, tests"
+mypy_path = "src"
+namespace_packages = true
+explicit_package_bases = true
+show_error_codes = true
+strict = true

tests/test_c4.py

@@ -3,47 +3,46 @@ import random
 import string
 import unittest
 
-from diagrams import Diagram
-from diagrams import setcluster, setdiagram
+from diagrams import setcluster, setdiagram, Diagram
 from diagrams.c4 import Person, Container, Database, System, SystemBoundary, Relationship
 
 
 class C4Test(unittest.TestCase):
-    def setUp(self):
-        self.name = "diagram-" + "".join([random.choice(string.hexdigits) for n in range(7)]).lower()
+    def setUp(self) -> None:
+        self.name: str = "diagram-" + "".join([random.choice(string.hexdigits) for n in range(7)]).lower()
 
-    def tearDown(self):
+    def tearDown(self) -> None:
         setdiagram(None)
         setcluster(None)
         try:
-            os.remove(self.name + ".png")
+            os.remove(f"{self.name}.png")
         except FileNotFoundError:
             pass
 
-    def test_nodes(self):
+    def test_nodes(self) -> None:
         with Diagram(name=self.name, show=False):
             person = Person("person", "A person.")
             container = Container("container", "Java application", "The application.")
             database = Database("database", "Oracle database", "Stores information.")
 
-    def test_external_nodes(self):
+    def test_external_nodes(self) -> None:
         with Diagram(name=self.name, show=False):
             external_person = Person("person", external=True)
             external_system = System("external", external=True)
 
-    def test_systems(self):
+    def test_systems(self) -> None:
         with Diagram(name=self.name, show=False):
             system = System("system", "The internal system.")
             system_without_description = System("unknown")
 
-    def test_edges(self):
+    def test_edges(self) -> None:
         with Diagram(name=self.name, show=False):
             c1 = Container("container1")
             c2 = Container("container2")
 
             c1 >> c2
 
-    def test_edges_with_labels(self):
+    def test_edges_with_labels(self) -> None:
         with Diagram(name=self.name, show=False):
             c1 = Container("container1")
             c2 = Container("container2")
@@ -51,14 +50,14 @@ class C4Test(unittest.TestCase):
             c1 >> Relationship("depends on") >> c2
             c1 << Relationship("is depended on by") << c2
 
-    def test_edge_without_constraint(self):
+    def test_edge_without_constraint(self) -> None:
         with Diagram(name=self.name, show=False):
             s1 = System("system 1")
             s2 = System("system 2")
 
-            s1 >> Relationship(constraint="False") >> s2
+            s1 >> Relationship(constraint="False") >> s2 # type: ignore[arg-type]
 
-    def test_cluster(self):
+    def test_cluster(self) -> None:
         with Diagram(name=self.name, show=False):
             with SystemBoundary("System"):
                 Container("container", "type", "description")

tests/test_diagram.py

@@ -3,15 +3,14 @@ import shutil
 import unittest
 import pathlib
 
-from diagrams import Cluster, Diagram, Edge, Node
-from diagrams import getcluster, getdiagram, setcluster, setdiagram
+from diagrams import Cluster, Diagram, Edge, Node, getcluster, getdiagram, setcluster, setdiagram
 
 
 class DiagramTest(unittest.TestCase):
-    def setUp(self):
-        self.name = "diagram_test"
+    def setUp(self) -> None:
+        self.name: str = "diagram_test"
 
-    def tearDown(self):
+    def tearDown(self) -> None:
         setdiagram(None)
         setcluster(None)
         # Only some tests generate the image file.
@@ -20,11 +19,11 @@ class DiagramTest(unittest.TestCase):
         except OSError:
             # Consider it file
             try:
-                os.remove(self.name + ".png")
+                os.remove(f"{self.name}.png")
             except FileNotFoundError:
                 pass
 
-    def test_validate_direction(self):
+    def test_validate_direction(self) -> None:
         # Normal directions.
         for dir in ("TB", "BT", "LR", "RL", "tb"):
             Diagram(direction=dir)
@@ -34,7 +33,7 @@ class DiagramTest(unittest.TestCase):
             with self.assertRaises(ValueError):
                 Diagram(direction=dir)
 
-    def test_validate_curvestyle(self):
+    def test_validate_curvestyle(self) -> None:
         # Normal directions.
         for cvs in ("ortho", "curved", "CURVED"):
             Diagram(curvestyle=cvs)
@@ -44,7 +43,7 @@ class DiagramTest(unittest.TestCase):
             with self.assertRaises(ValueError):
                 Diagram(curvestyle=cvs)
 
-    def test_validate_outformat(self):
+    def test_validate_outformat(self) -> None:
         # Normal output formats.
         for fmt in ("png", "jpg", "svg", "pdf", "PNG", "dot"):
             Diagram(outformat=fmt)
@@ -54,18 +53,18 @@ class DiagramTest(unittest.TestCase):
             with self.assertRaises(ValueError):
                 Diagram(outformat=fmt)
 
-    def test_with_global_context(self):
+    def test_with_global_context(self) -> None:
         self.assertIsNone(getdiagram())
         with Diagram(name=os.path.join(self.name, "with_global_context"), show=False):
             self.assertIsNotNone(getdiagram())
         self.assertIsNone(getdiagram())
 
-    def test_node_not_in_diagram(self):
+    def test_node_not_in_diagram(self) -> None:
         # Node must be belong to a diagrams.
         with self.assertRaises(EnvironmentError):
             Node("node")
 
-    def test_node_to_node(self):
+    def test_node_to_node(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_node"), show=False):
             node1 = Node("node1")
             node2 = Node("node2")
@@ -73,7 +72,7 @@ class DiagramTest(unittest.TestCase):
             self.assertEqual(node1 >> node2, node2)
             self.assertEqual(node1 << node2, node2)
 
-    def test_node_to_nodes(self):
+    def test_node_to_nodes(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_nodes"), show=False):
             node1 = Node("node1")
             nodes = [Node("node2"), Node("node3")]
@@ -81,7 +80,7 @@ class DiagramTest(unittest.TestCase):
             self.assertEqual(node1 >> nodes, nodes)
             self.assertEqual(node1 << nodes, nodes)
 
-    def test_nodes_to_node(self):
+    def test_nodes_to_node(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node"), show=False):
             node1 = Node("node1")
             nodes = [Node("node2"), Node("node3")]
@@ -89,32 +88,31 @@ class DiagramTest(unittest.TestCase):
             self.assertEqual(nodes >> node1, node1)
             self.assertEqual(nodes << node1, node1)
 
-    def test_default_filename(self):
+    def test_default_filename(self) -> None:
         self.name = "example_1"
         with Diagram(name="Example 1", show=False):
             Node("node1")
         self.assertTrue(os.path.exists(f"{self.name}.png"))
 
-    def test_custom_filename(self):
+    def test_custom_filename(self) -> None:
         self.name = "my_custom_name"
         with Diagram(name="Example 1", filename=self.name, show=False):
             Node("node1")
         self.assertTrue(os.path.exists(f"{self.name}.png"))
 
-    def test_empty_name(self):
+    def test_empty_name(self) -> None:
         """Check that providing an empty name don't crash, but save in a diagrams_image.xxx file."""
         self.name = 'diagrams_image'
         with Diagram(show=False):
             Node("node1")
         self.assertTrue(os.path.exists(f"{self.name}.png"))
     
-    def test_autolabel(self):
+    def test_autolabel(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node"), show=False):
             node1 = Node("node1")
             self.assertTrue(node1.label,"Node\nnode1")
 
-
-    def test_outformat_list(self):
+    def test_outformat_list(self) -> None:
         """Check that outformat render all the files from the list."""
         self.name = 'diagrams_image'
         with Diagram(show=False, outformat=["dot", "png"]):
@@ -128,10 +126,10 @@ class DiagramTest(unittest.TestCase):
 
 
 class ClusterTest(unittest.TestCase):
-    def setUp(self):
-        self.name = "cluster_test"
+    def setUp(self) -> None:
+        self.name: str = "cluster_test"
 
-    def tearDown(self):
+    def tearDown(self) -> None:
         setdiagram(None)
         setcluster(None)
         # Only some tests generate the image file.
@@ -140,7 +138,7 @@ class ClusterTest(unittest.TestCase):
         except OSError:
             pass
 
-    def test_validate_direction(self):
+    def test_validate_direction(self) -> None:
         # Normal directions.
         for dir in ("TB", "BT", "LR", "RL"):
             with Diagram(name=os.path.join(self.name, "validate_direction"), show=False):
@@ -152,14 +150,14 @@ class ClusterTest(unittest.TestCase):
                 with Diagram(name=os.path.join(self.name, "validate_direction"), show=False):
                     Cluster(direction=dir)
 
-    def test_with_global_context(self):
+    def test_with_global_context(self) -> None:
         with Diagram(name=os.path.join(self.name, "with_global_context"), show=False):
             self.assertIsNone(getcluster())
             with Cluster():
                 self.assertIsNotNone(getcluster())
             self.assertIsNone(getcluster())
 
-    def test_with_nested_cluster(self):
+    def test_with_nested_cluster(self) -> None:
         with Diagram(name=os.path.join(self.name, "with_nested_cluster"), show=False):
             self.assertIsNone(getcluster())
             with Cluster() as c1:
@@ -169,12 +167,12 @@ class ClusterTest(unittest.TestCase):
                 self.assertEqual(c1, getcluster())
             self.assertIsNone(getcluster())
 
-    def test_node_not_in_diagram(self):
+    def test_node_not_in_diagram(self) -> None:
         # Node must be belong to a diagrams.
         with self.assertRaises(EnvironmentError):
             Node("node")
 
-    def test_node_to_node(self):
+    def test_node_to_node(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_node"), show=False):
             with Cluster():
                 node1 = Node("node1")
@@ -183,7 +181,7 @@ class ClusterTest(unittest.TestCase):
                 self.assertEqual(node1 >> node2, node2)
                 self.assertEqual(node1 << node2, node2)
 
-    def test_node_to_nodes(self):
+    def test_node_to_nodes(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_nodes"), show=False):
             with Cluster():
                 node1 = Node("node1")
@@ -192,7 +190,7 @@ class ClusterTest(unittest.TestCase):
                 self.assertEqual(node1 >> nodes, nodes)
                 self.assertEqual(node1 << nodes, nodes)
 
-    def test_nodes_to_node(self):
+    def test_nodes_to_node(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node"), show=False):
             with Cluster():
                 node1 = Node("node1")
@@ -203,10 +201,10 @@ class ClusterTest(unittest.TestCase):
 
 
 class EdgeTest(unittest.TestCase):
-    def setUp(self):
-        self.name = "edge_test"
+    def setUp(self) -> None:
+        self.name: str = "edge_test"
 
-    def tearDown(self):
+    def tearDown(self) -> None:
         setdiagram(None)
         setcluster(None)
         # Only some tests generate the image file.
@@ -215,34 +213,34 @@ class EdgeTest(unittest.TestCase):
         except OSError:
             pass
 
-    def test_node_to_node(self):
+    def test_node_to_node(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_node"), show=False):
             node1 = Node("node1")
             node2 = Node("node2")
             self.assertEqual(node1 - Edge(color="red") - node2, node2)
 
-    def test_node_to_nodes(self):
+    def test_node_to_nodes(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_nodes"), show=False):
             with Cluster():
                 node1 = Node("node1")
                 nodes = [Node("node2"), Node("node3")]
-                self.assertEqual(node1 - Edge(color="red") - nodes, nodes)
+                self.assertEqual(node1 - Edge(color="red") - nodes, nodes) # type: ignore[operator]
 
-    def test_nodes_to_node(self):
+    def test_nodes_to_node(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node"), show=False):
             with Cluster():
                 node1 = Node("node1")
                 nodes = [Node("node2"), Node("node3")]
                 self.assertEqual(nodes - Edge(color="red") - node1, node1)
 
-    def test_nodes_to_node_with_additional_attributes(self):
+    def test_nodes_to_node_with_additional_attributes(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node_with_additional_attributes"), show=False):
             with Cluster():
                 node1 = Node("node1")
                 nodes = [Node("node2"), Node("node3")]
                 self.assertEqual(nodes - Edge(color="red") - Edge(color="green") - node1, node1)
 
-    def test_node_to_node_with_attributes(self):
+    def test_node_to_node_with_attributes(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_node_with_attributes"), show=False):
             with Cluster():
                 node1 = Node("node1")
@@ -251,7 +249,7 @@ class EdgeTest(unittest.TestCase):
                 self.assertEqual(node1 >> Edge(color="green", label="1.2") >> node2, node2)
                 self.assertEqual(node1 << Edge(color="blue", label="1.3") >> node2, node2)
 
-    def test_node_to_node_with_additional_attributes(self):
+    def test_node_to_node_with_additional_attributes(self) -> None:
         with Diagram(name=os.path.join(self.name, "node_to_node_with_additional_attributes"), show=False):
             with Cluster():
                 node1 = Node("node1")
@@ -260,7 +258,7 @@ class EdgeTest(unittest.TestCase):
                 self.assertEqual(node1 >> Edge(color="green", label="2.2") >> Edge(color="red") >> node2, node2)
                 self.assertEqual(node1 << Edge(color="blue", label="2.3") >> Edge(color="black") >> node2, node2)
 
-    def test_nodes_to_node_with_attributes_loop(self):
+    def test_nodes_to_node_with_attributes_loop(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node_with_attributes_loop"), show=False):
             with Cluster():
                 node = Node("node")
@@ -269,21 +267,21 @@ class EdgeTest(unittest.TestCase):
                 self.assertEqual(node >> Edge(color="blue", label="3.3") << node, node)
                 self.assertEqual(node << Edge(color="pink", label="3.4") >> node, node)
 
-    def test_nodes_to_node_with_attributes_bothdirectional(self):
+    def test_nodes_to_node_with_attributes_bothdirectional(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node_with_attributes_bothdirectional"), show=False):
             with Cluster():
                 node1 = Node("node1")
                 nodes = [Node("node2"), Node("node3")]
                 self.assertEqual(nodes << Edge(color="green", label="4") >> node1, node1)
 
-    def test_nodes_to_node_with_attributes_bidirectional(self):
+    def test_nodes_to_node_with_attributes_bidirectional(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node_with_attributes_bidirectional"), show=False):
             with Cluster():
                 node1 = Node("node1")
                 nodes = [Node("node2"), Node("node3")]
                 self.assertEqual(nodes << Edge(color="blue", label="5") >> node1, node1)
 
-    def test_nodes_to_node_with_attributes_onedirectional(self):
+    def test_nodes_to_node_with_attributes_onedirectional(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node_with_attributes_onedirectional"), show=False):
             with Cluster():
                 node1 = Node("node1")
@@ -291,7 +289,7 @@ class EdgeTest(unittest.TestCase):
                 self.assertEqual(nodes >> Edge(color="red", label="6.1") >> node1, node1)
                 self.assertEqual(nodes << Edge(color="green", label="6.2") << node1, node1)
 
-    def test_nodes_to_node_with_additional_attributes_directional(self):
+    def test_nodes_to_node_with_additional_attributes_directional(self) -> None:
         with Diagram(name=os.path.join(self.name, "nodes_to_node_with_additional_attributes_directional"), show=False):
             with Cluster():
                 node1 = Node("node1")
@@ -305,7 +303,7 @@ class EdgeTest(unittest.TestCase):
 
 
 class ResourcesTest(unittest.TestCase):
-    def test_folder_depth(self):
+    def test_folder_depth(self) -> None:
         """
         The code currently only handles resource folders up to a dir depth of 2
         i.e. resources/<provider>/<type>/<image>, so check that this depth isn't