Updating the index.d.ts and adding a test

Author: rustedgrail

index.d.ts

@@ -109,7 +109,14 @@ declare module '@dagrejs/dagre' {
     labeloffest?: number | undefined;
   }
 
-  export function layout(graph: graphlib.Graph, layout?: GraphLabel & NodeConfig & EdgeConfig): void;
+  export interface LayoutConfig {
+    customOrder?: (graph: graphlib.Graph, order: (graph: graphlib.Graph, opts: configUnion) => void) => void;
+    disableOptimalOrderHeuristic?: boolean;
+  }
+
+  type configUnion = GraphLabel & NodeConfig & EdgeConfig & LayoutConfig;
+
+  export function layout(graph: graphlib.Graph, layout?: configUnion): void;
 
   export interface Edge {
     v: string;

lib/order/index.js

@@ -26,8 +26,8 @@ module.exports = order;
  *       algorithm.
  */
 function order(g, opts) {
-  if (opts && opts.customOrder) {
-    opts.customOrder(order, g);
+  if (opts && typeof opts.customOrder === 'function') {
+    opts.customOrder(g, order);
     return;
   }
 

package-lock.json

@@ -43,4 +43,20 @@ describe("order", function() {
     var layering = util.buildLayerMatrix(g);
     expect(crossCount(g, layering)).to.be.lte(1);
   });
+
+  it('can skip the optimal ordering', () => {
+    g.setNode("a", { rank: 1 });
+    ["b", "d"].forEach(v => g.setNode(v, { rank: 2 }));
+    ["c", "e"].forEach(v => g.setNode(v, { rank: 3 }));
+    g.setPath(["a", "b", "c"]);
+    g.setPath(["a", "d"]);
+    g.setEdge("b", "e");
+    g.setEdge("d", "c");
+
+    const opts = { disableOptimalOrderHeuristic: true };
+
+    order(g, opts);
+    var layering = util.buildLayerMatrix(g);
+    expect(crossCount(g, layering)).to.equal(1);
+  });
 });