Function formatMermaidNode

repos/effect/packages/effect/src/Graph.ts:2322–2347

(
  nodeId: string,
  label: string,
  shape: MermaidNodeShape
)

  // Second pass: remove filtered out nodes and their edges
  removeNodes(mutable, remove)
}

/**
 * Filters and optionally transforms edges in a mutable graph using a predicate function.
 * Edges that return Option.none are removed from the graph.
 *
 * **Gotchas**
 *
 * The function may query the graph, but cannot mutate or finalize the same
 * graph while it runs. Retained payloads must remain the same edge type.
 *
 * **Example** (Filtering and mapping edges)
 *
 * ```ts import.meta.vitest
 * import { Graph, Option } from "effect"
 *
 * const graph = Graph.directed<string, number>((mutable) => {
 *   const a = Graph.addNode(mutable, "A")
 *   const b = Graph.addNode(mutable, "B")
 *   const c = Graph.addNode(mutable, "C")
 *   Graph.addEdge(mutable, a, b, 5)
 *   Graph.addEdge(mutable, b, c, 15)
 *   Graph.addEdge(mutable, c, a, 25)
 *
 *   // Keep only edges with weight >= 10 and double their weight
 *   Graph.filterMapEdges(
 *     mutable,
 *     (data) => data >= 10 ? Option.some(data * 2) : Option.none()