chore: Update IndexedNode to always have a parentId property

src/models/session/logic.test.ts

@@ -1,7 +1,5 @@
 import type { OrderedBreadcrumbs, OrderedFlow } from "../../types";
-import { ComponentType } from "../../types";
-import { findNextNodeOfType, sortBreadcrumbs, sortFlow } from "./logic";
-import * as branching from "./mocks/branching-flow";
+import { sortBreadcrumbs, sortFlow } from "./logic";
 import * as complex from "./mocks/complex-flow-breadcrumbs";
 import * as large from "./mocks/large-real-life-flow";
 import * as sectioned from "./mocks/section-flow-breadcrumbs";
@@ -77,67 +75,6 @@ describe("sortBreadcrumbs", () => {
   });
 });
 
-describe("findNextNodeOfType", () => {
-  test("it finds the next node in a simple flow", () => {
-    const nextNode = findNextNodeOfType({
-      flow: simple.flow,
-      breadcrumbs: {
-        firstQuestion: {
-          auto: false,
-          answers: ["firstAnswer"],
-        },
-      },
-      componentType: ComponentType.Question,
-    });
-    expect(nextNode).toEqual({
-      id: "secondQuestion",
-      parentId: "firstQuestion",
-      type: ComponentType.Question,
-      edges: ["secondAnswer"],
-      data: {
-        text: "Second Question",
-      },
-    });
-  });
-
-  test("it finds the next node in a branching flow", () => {
-    const multiselectChecklistBreadcrumbs = {
-      Section1: { auto: true },
-      Question1: { auto: false, answers: ["Question1AnswerA"] },
-      Section2: { auto: true },
-      Question2: { auto: false, answers: ["Question2AnswerB"] },
-      Checklist1: {
-        auto: false,
-        answers: ["ChecklistOptionB", "ChecklistOptionC"],
-      },
-    };
-    const nextNoticeNode = findNextNodeOfType({
-      flow: branching.flow,
-      breadcrumbs: multiselectChecklistBreadcrumbs,
-      componentType: ComponentType.Notice,
-    });
-    expect(nextNoticeNode).toEqual({
-      id: "NoticeB",
-      parentId: "ChecklistOptionB", // this isn't really the parent but the previous node
-      sectionId: "Section2",
-      data: { color: "#EFEFEF", title: "Reached B", resetButton: false },
-      type: ComponentType.Notice,
-    });
-    const nextSectionNode = findNextNodeOfType({
-      flow: branching.flow,
-      breadcrumbs: multiselectChecklistBreadcrumbs,
-      componentType: ComponentType.Section,
-    });
-    expect(nextSectionNode).toEqual({
-      id: "Section3",
-      parentId: "EndOfSection2Notice",
-      sectionId: "Section3",
-      data: { title: "Section Three" },
-      type: ComponentType.Section,
-    });
-  });
-});
-
 function expectReasonableExecutionTime<T>(fn: () => T, timeout: number): T {
   const testStartTime = new Date().getTime();
   const out = fn();

src/models/session/logic.ts

@@ -14,7 +14,7 @@ import { ComponentType } from "../../types";
 export function sortFlow(flow: FlowGraph): OrderedFlow {
   let sectionId: string | undefined;
   const nodes: IndexedNode[] = [];
-  const searchNodeEdges = (id: string, parentId?: string) => {
+  const searchNodeEdges = (id: string, parentId: string) => {
     // skip already added nodes
     if (nodes.map((n) => n.id).includes(id)) return;
     const foundNode = flow[id];
@@ -27,21 +27,21 @@ export function sortFlow(flow: FlowGraph): OrderedFlow {
     sectionId = foundNode.type == ComponentType.Section ? id : sectionId;
     nodes.push({
       id,
-      parentId: parentId || null,
-      sectionId,
+      parentId,
+      ...(sectionId && { sectionId }),
       type: foundNode.type!,
-      edges: foundNode.edges,
+      ...(foundNode.edges && { edges: foundNode.edges }),
       data: foundNode.data,
     });
     foundNode.edges?.forEach((childEdgeId) => {
       searchNodeEdges(childEdgeId, id);
     });
   };
-  let parentId: string;
+
   flow._root.edges.forEach((rootEdgeId) => {
-    searchNodeEdges(rootEdgeId, parentId);
-    parentId = rootEdgeId;
+    searchNodeEdges(rootEdgeId, "_root");
   });
+
   return nodes;
 }
 
@@ -107,41 +107,6 @@ export function sortBreadcrumbs(
   return orderedBreadcrumbs;
 }
 
-export function findNextNodeOfType({
-  flow,
-  breadcrumbs,
-  componentType,
-}: {
-  flow: FlowGraph;
-  breadcrumbs: Breadcrumbs;
-  componentType: ComponentType;
-}): IndexedNode | undefined {
-  const orderedBreadcrumbs = sortBreadcrumbs(flow, breadcrumbs);
-  const lastCrumb = orderedBreadcrumbs.at(-1)!;
-  const sortedFlow = sortFlow(flow);
-  const sortedFlowLastNodeIndex = sortedFlow.findIndex(
-    (n) => n.id == lastCrumb.id,
-  );
-  const truncatedFlow = sortedFlow.slice(sortedFlowLastNodeIndex);
-
-  for (const node of truncatedFlow) {
-    const parentNodeIsLastCrumb = node.parentId === lastCrumb.id;
-    if (parentNodeIsLastCrumb && node.type === componentType) {
-      return node;
-    }
-    const parentNodeIsCrumbAnswer =
-      node.parentId &&
-      lastCrumb.answers &&
-      lastCrumb.answers.includes(node.parentId!);
-    if (parentNodeIsCrumbAnswer && node.type === componentType) {
-      return node;
-    }
-  }
-  // when the above fails, fallback to a naïve scan of matching upcoming nodes
-  // FIXME: this approach does not respect flow branching logic
-  return truncatedFlow.find((n) => n.type === componentType);
-}
-
 const isSectionNode = (nodeOrCrumb: Node | Crumb): nodeOrCrumb is Node =>
   "type" in nodeOrCrumb && nodeOrCrumb.type === ComponentType.Section;
 

src/models/session/mocks/complex-flow-breadcrumbs.ts

@@ -228,7 +228,7 @@ export const flow: FlowGraph = {
 export const orderedFlow: OrderedFlow = [
   {
     id: "Imks7j68BD",
-    parentId: null,
+    parentId: "_root",
     data: {
       fn: "item",
       text: "shopping trolley",
@@ -275,7 +275,7 @@ export const orderedFlow: OrderedFlow = [
   },
   {
     id: "HV0gV8DOil",
-    parentId: "Imks7j68BD",
+    parentId: "_root",
     data: {
       fn: "item",
       text: "shopping trolley (should be skipped)",
@@ -322,7 +322,7 @@ export const orderedFlow: OrderedFlow = [
   },
   {
     id: "2PT6bTPTqj",
-    parentId: "HV0gV8DOil",
+    parentId: "_root",
     data: {
       fn: "item",
       text: "contains",
@@ -411,7 +411,7 @@ export const orderedFlow: OrderedFlow = [
   },
   {
     id: "3H2bGdzpIN",
-    parentId: "2PT6bTPTqj",
+    parentId: "_root",
     data: {
       fn: "item",
       text: "Does the basket contain apples?",
@@ -438,7 +438,7 @@ export const orderedFlow: OrderedFlow = [
   },
   {
     id: "AFX3QwbOCd",
-    parentId: "3H2bGdzpIN",
+    parentId: "_root",
     data: {
       fn: "item",
       text: "Which does the basket contain?",
@@ -497,7 +497,7 @@ export const normalizedFlow: NormalizedFlow = [
       allRequired: false,
     },
     type: ComponentType.Checklist,
-    parentId: null,
+    parentId: "_root",
     rootNodeId: "Imks7j68BD",
     edges: ["EqfqaqZ6CH", "I8DznYCKVg", "pXFKKRG6lE", "7tV1uvR9ng"],
   },