Display tie lines in NAD while using a voltage level and a depth as inputs

[So-Fras]

Describe the current behavior

When trying to display a network area diagram including a tie line, there is an exception raised when a filter is used: if both voltage levels at each end of a tie line are not included as inputs, the algorithm in VoltageLevelFilter does not manage to travel across the tie line from one voltage level to the other.

Describe the expected behavior

The algorithm should be able to travel across a tie line in order to display a central voltage level with a chosen depth of neighbouring voltage levels (as it is already the case when there is no tie line).

Describe the steps

// Create a network with tie lines
Network network = EurostagTutorialExample1Factory.createWithTieLine();

// Display part of the network, centered on one end of the tie line
NetworkAreaDiagram.draw(network, Path.of("/path/to/output/outputTest.svg"), "VLHV1", 1);

Environment

powsybl-diagram 3.3.2

Relevant Log Output

com.powsybl.commons.PowsyblException: Cannot add edge, corresponding voltage level is unknown: 'VLHV2'

at com.powsybl.nad.build.iidm.NetworkGraphBuilder.lambda$getVoltageLevelNode$11(NetworkGraphBuilder.java:200)
at java.base/java.util.Optional.orElseThrow(Optional.java:403)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.getVoltageLevelNode(NetworkGraphBuilder.java:200)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.addEdge(NetworkGraphBuilder.java:160)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.addEdge(NetworkGraphBuilder.java:155)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.visitTieLine(NetworkGraphBuilder.java:126)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.lambda$visitDanglingLine$9(NetworkGraphBuilder.java:121)
at java.base/java.util.Optional.ifPresent(Optional.java:178)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.visitDanglingLine(NetworkGraphBuilder.java:121)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.lambda$addGraphEdges$7(NetworkGraphBuilder.java:78)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.lambda$buildGraph$2(NetworkGraphBuilder.java:58)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
at com.powsybl.nad.build.iidm.NetworkGraphBuilder.buildGraph(NetworkGraphBuilder.java:58)
at com.powsybl.nad.NetworkAreaDiagram.genericDraw(NetworkAreaDiagram.java:82)
at com.powsybl.nad.NetworkAreaDiagram.draw(NetworkAreaDiagram.java:69)
at com.powsybl.nad.NetworkAreaDiagram.draw(NetworkAreaDiagram.java:45)
at com.powsybl.nad.svg.TieLineTest.testTieLineBug ...

Extra Information

No response

[So-Fras]

In private static class VlVisitor extends DefaultTopologyVisitor { ...}, we forgot to override the visitDanglingLine(...) function:

       @Override
        public void visitDanglingLine(DanglingLine danglingLine) {
            if (danglingLine.isPaired()) {
                danglingLine.getTieLine().ifPresent(tieline -> visitBranch(tieline, tieline.getSide(danglingLine.getTerminal())));
            }
        }

Adding that solves the above problem. We can run the following lines without any errors:

        Network network = EurostagTutorialExample1Factory.createWithTieLine();
        NetworkAreaDiagram.draw(network, Path.of("/path/to/output/outputTest.svg"), "VLHV1", 1);

I think we should add a test to the TieLineTest class to ensure that this case is now covered.