State Design Pattern

An example of the State design pattern in C#.

New Mermaid syntax:

stateDiagram-v2
  [*] --> Unwritten
  
  Unwritten --> Open: Open
  Unwritten --> Void: Void
  
  Open --> Void: Void
  Open --> Cancelled: Cancel
  Open --> Closed: Close
  Open --> Open: Update
  
  Closed --> Open: Open

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State Transition Diagram (copy here):

digraph PolicyState {
  size="8,5"
  node [shape = doublecircle]; Unwritten;
  node [shape = rectangle style=filled]; Void Cancelled;
  node [shape = circle];
  Unwritten -> Open [ label = "Open" ];
  Unwritten -> Void[ label = "Void" ];
  Open -> Cancelled [ label = "Cancel" ];
  Open -> Closed [label = "Close" ];
  Open -> Open [label = "Update"];
  Open -> Void [label = "Void"];
  Closed -> Open [label = "Open"];
  Void [color="0.000 1.000 1.000"];
  Cancelled [color="0.201 0.753 1.000"];
}

Notes

The State pattern is described in the Core project and tested in the unit tests. The web project doesn't yet do anything useful. Pull requests welcome to help visualize the pattern.

Added a GitHub Action that eventually will build and run tests.