Adding more comments and fixing type errors

x-pack/plugins/security_solution/server/endpoint/routes/resolver/queries/base.ts

@@ -14,8 +14,10 @@ import { MSearchQuery } from './multi_searcher';
 /**
  * ResolverQuery provides the base structure for queries to retrieve events when building a resolver graph.
  *
- * @param T the structured return type of a resolver query. This represents the type that is returned when translating
- * Elasticsearch's SearchResponse<ResolverEvent> response.
+ * @param T the structured return type of a resolver query. This represents the final return type of the query after handling
+ * any aggregations.
+ * @param R the is the type after transforming ES's response. Making this definable let's us set whether it is a resolver event
+ * or something else.
  */
 export abstract class ResolverQuery<T, R = ResolverEvent> implements MSearchQuery {
   /**

x-pack/plugins/security_solution/server/endpoint/routes/resolver/queries/stats.ts

@@ -13,9 +13,12 @@ export interface StatsResult {
   events: Record<string, EventStats>;
 }
 
-interface CategoriesAgg {
+interface AggBucket {
   key: string;
   doc_count: number;
+}
+
+interface CategoriesAgg extends AggBucket {
   /**
    * The reason categories is optional here is because if no data was returned in the query the categories aggregation
    * will not be defined on the response (because it's a sub aggregation).

x-pack/plugins/security_solution/server/endpoint/routes/resolver/utils/ancestry_query_handler.ts

@@ -14,7 +14,7 @@ import {
 import {
   ResolverAncestry,
   ResolverEvent,
-  LifecycleNode,
+  ResolverLifecycleNode,
 } from '../../../../../common/endpoint/types';
 import { createAncestry, createLifecycle } from './node';
 import { LifecycleQuery } from '../queries/lifecycle';
@@ -33,7 +33,7 @@ export class AncestryQueryHandler implements QueryHandler<ResolverAncestry> {
     private levels: number,
     indexPattern: string,
     legacyEndpointID: string | undefined,
-    originNode: LifecycleNode | undefined
+    originNode: ResolverLifecycleNode | undefined
   ) {
     this.ancestorsToFind = getAncestryAsArray(originNode?.lifecycle[0]).slice(0, levels);
     this.query = new LifecycleQuery(indexPattern, legacyEndpointID);
@@ -46,7 +46,7 @@ export class AncestryQueryHandler implements QueryHandler<ResolverAncestry> {
   }
 
   private toMapOfNodes(results: ResolverEvent[]) {
-    return results.reduce((nodes: Map<string, LifecycleNode>, event: ResolverEvent) => {
+    return results.reduce((nodes: Map<string, ResolverLifecycleNode>, event: ResolverEvent) => {
       const nodeId = entityId(event);
       let node = nodes.get(nodeId);
       if (!node) {

x-pack/plugins/security_solution/server/endpoint/routes/resolver/utils/children_helper.ts

@@ -37,21 +37,21 @@ export class ChildrenNodesHelper {
     let rootNextChild = null;
 
     if (rootNode) {
-      rootNextChild = rootNode.nextChild;
+      rootNextChild = rootNode.nextChild ?? null;
     }
 
     cacheCopy.delete(this.rootID);
     return {
       childNodes: Array.from(cacheCopy.values()),
-      nextChild: rootNextChild || null,
+      nextChild: rootNextChild,
     };
   }
 
   /**
    * Get the entity_ids of the nodes that are cached.
    */
   getEntityIDs(): string[] {
-    const cacheCopy: Map<string, ChildNode> = new Map(this.entityToNodeCache);
+    const cacheCopy: Map<string, ResolverChildNode> = new Map(this.entityToNodeCache);
     cacheCopy.delete(this.rootID);
     return Array.from(cacheCopy.keys());
   }
@@ -89,7 +89,7 @@ export class ChildrenNodesHelper {
   addStartEvents(queriedNodes: Set<string>, startEvents: ResolverEvent[]): Set<string> | undefined {
     let largestAncestryArray = 0;
     const nodesToQueryNext: Map<number, Set<string>> = new Map();
-    const nonLeafNodes: Set<ChildNode> = new Set();
+    const nonLeafNodes: Set<ResolverChildNode> = new Set();
 
     const isDistantGrandchild = (event: ResolverEvent) => {
       const ancestry = getAncestryAsArray(event);

x-pack/plugins/security_solution/server/endpoint/routes/resolver/utils/lifecycle_query_handler.ts

@@ -6,7 +6,7 @@
 
 import { SearchResponse } from 'elasticsearch';
 import { IScopedClusterClient } from 'src/core/server';
-import { ResolverEvent, LifecycleNode } from '../../../../../common/endpoint/types';
+import { ResolverEvent, ResolverLifecycleNode } from '../../../../../common/endpoint/types';
 import { LifecycleQuery } from '../queries/lifecycle';
 import { QueryInfo } from '../queries/multi_searcher';
 import { SingleQueryHandler } from './fetch';
@@ -15,8 +15,8 @@ import { createLifecycle } from './node';
 /**
  * Retrieve the lifecycle events for a node.
  */
-export class LifecycleQueryHandler implements SingleQueryHandler<LifecycleNode> {
-  private lifecycle: LifecycleNode | undefined;
+export class LifecycleQueryHandler implements SingleQueryHandler<ResolverLifecycleNode> {
+  private lifecycle: ResolverLifecycleNode | undefined;
   private readonly query: LifecycleQuery;
   constructor(
     private readonly entityID: string,
@@ -51,7 +51,7 @@ export class LifecycleQueryHandler implements SingleQueryHandler<LifecycleNode>
   /**
    * Get the results from the msearch.
    */
-  getResults(): LifecycleNode | undefined {
+  getResults(): ResolverLifecycleNode | undefined {
     return this.lifecycle;
   }
 

x-pack/plugins/security_solution/server/endpoint/routes/resolver/utils/node.ts

@@ -84,7 +84,7 @@ export function createLifecycle(
  * @param nextChild the cursor for the response
  */
 export function createChildren(
-  nodes: ChildNode[] = [],
+  nodes: ResolverChildNode[] = [],
   nextChild: string | null = null
 ): ResolverChildren {
   return { childNodes: nodes, nextChild };

x-pack/plugins/security_solution/server/endpoint/routes/resolver/utils/tree.test.ts

@@ -20,7 +20,7 @@ describe('Tree', () => {
     // transform the generator's array of events into the format expected by the tree class
     const ancestorInfo: ResolverAncestry = {
       ancestors: generator
-        .createAlertEventAncestry(5, 0, 0)
+        .createAlertEventAncestry({ ancestors: 5, percentTerminated: 0, percentWithRelated: 0 })
         .filter((event) => {
           return event.event.kind === 'event';
         })