Judging from this an approach might have been to port the 28 modules individually and check that everything returns the same data in Perl and TS versions:

"I took a long-overdue peek at the source codebase. Over 30,000 lines of battle-tested Perl across 28 modules. A* pathfinding for edge routing, hierarchical group rendering, port configurations for node connections, bidirectional edges, collapsing multi-edges. I hadn’t expected the sheer interwoven complexity."