Square bracket to half a rectangle

Hello
I want to make a square bracket up to half a rectangle But horizontal lines stretch to the end.
I use geometryString.
image
I want something like this
image
How can I do it?

Could you please show us how you defined your Shape and the Panel that it is in?

You can see example here - https://codepen.io/alexzanel/pen/dLEVQb

Maybe you need to set Shape.geometryStretch.

    myDiagram.nodeTemplate =
      $(go.Node, "Spot",
        $(go.Shape,
          {
            strokeWidth: 3,
            geometryString: "M30 0 L0 0 0 30 30 30",
            geometryStretch: go.GraphObject.None
          },
          new go.Binding("stroke", "color")),
        $(go.TextBlock,
          { alignment: new go.Spot(0, 0.5, 6, 0), alignmentFocus: go.Spot.Left },
          new go.Binding("text"))
      );

image

Yes it works, but how to make it resizable?

I thought you didn’t want it to be resizable.

OK, have the geometry stretch with the Shape:

      $(go.Node, "Auto",
        { resizable: true },
        $(go.Shape,
          { strokeWidth: 3, geometryString: "M1 0 L0 0 0 1 1 1 M2 1" },
          new go.Binding("stroke", "color")),
        $(go.TextBlock,
          { margin: 3 },
          new go.Binding("text"))
      );

But then the border does not stretch

Look again at the node template. See the differences from what I posted first?

Thank you so much