From 2dbc144b8f226f93b2c435b431f9b5862da2e0cb Mon Sep 17 00:00:00 2001
From: Pierre Gayvallet <pierre.gayvallet@elastic.co>
Date: Thu, 29 Sep 2022 19:41:06 +0200
Subject: [PATCH] Fix SO export sorting algorithm (#142078)

* Fix SO export sorting algorithm

* improve var name

* adapt another unit  test

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>
(cherry picked from commit 4cdd74dfcd71edaeae536220400310c271ee8a41)
---
 .../export/saved_objects_exporter.test.ts     |  6 ++-
 .../saved_objects/export/sort_objects.test.ts | 37 +++++++++++++++++++
 .../saved_objects/export/sort_objects.ts      | 21 ++++++-----
 3 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/src/core/server/saved_objects/export/saved_objects_exporter.test.ts b/src/core/server/saved_objects/export/saved_objects_exporter.test.ts
index 5968c8dabe8a8..411731c91493c 100644
--- a/src/core/server/saved_objects/export/saved_objects_exporter.test.ts
+++ b/src/core/server/saved_objects/export/saved_objects_exporter.test.ts
@@ -146,16 +146,18 @@ describe('getSortedObjectsForExport()', () => {
           attributes = {},
           sort = [],
           type = 'index-pattern',
+          idPrefix = '',
         }: {
           attributes?: Record<string, unknown>;
           sort?: string[];
           type?: string;
+          idPrefix?: string;
         } = {}
       ) {
         const hits = [];
         for (let i = 1; i <= hitCount; i++) {
           hits.push({
-            id: `${i}`,
+            id: `${idPrefix}${i}`,
             type,
             attributes,
             sort,
@@ -247,7 +249,7 @@ describe('getSortedObjectsForExport()', () => {
 
       describe('>1k hits', () => {
         const firstMockHits = generateHits(1000, { sort: ['a', 'b'] });
-        const secondMockHits = generateHits(500);
+        const secondMockHits = generateHits(500, { idPrefix: 'second-hit-' });
 
         test('requests multiple pages', async () => {
           savedObjectsClient.find.mockResolvedValueOnce({
diff --git a/src/core/server/saved_objects/export/sort_objects.test.ts b/src/core/server/saved_objects/export/sort_objects.test.ts
index 1f663ea5dbc56..27fbb09a37018 100644
--- a/src/core/server/saved_objects/export/sort_objects.test.ts
+++ b/src/core/server/saved_objects/export/sort_objects.test.ts
@@ -6,7 +6,9 @@
  * Side Public License, v 1.
  */
 
+import { range } from 'lodash';
 import { sortObjects } from './sort_objects';
+import type { SavedObject } from '@kbn/core-saved-objects-common';
 
 describe('sortObjects()', () => {
   test('should return on empty array', () => {
@@ -309,6 +311,7 @@ describe('sortObjects()', () => {
       ]
     `);
   });
+
   test('should not fail on complex circular dependencies', () => {
     const docs = [
       {
@@ -424,4 +427,38 @@ describe('sortObjects()', () => {
       ]
     `);
   });
+
+  test('should not fail on large graph of objects', () => {
+    // create an object that references all objects with a higher `index` up to `depth`.
+    const createComplexNode = (index: number, depth: number): SavedObject => {
+      return {
+        type: 'test',
+        id: `${index}`,
+        attributes: {},
+        references: range(index + 1, depth).map((refIndex) => ({
+          type: 'test',
+          id: `${refIndex}`,
+          name: `test-${refIndex}`,
+        })),
+      };
+    };
+
+    const createComplexGraph = (depth: number): SavedObject[] => {
+      const nodes: SavedObject[] = [];
+      for (let i = 0; i < depth; i++) {
+        nodes.push(createComplexNode(i, depth));
+      }
+      return nodes;
+    };
+
+    const depth = 100;
+    const graph = createComplexGraph(depth);
+    const sorted = sortObjects(graph);
+
+    expect(sorted.map(({ type, id }) => `${type}:${id}`)).toEqual(
+      range(depth)
+        .reverse()
+        .map((index) => `test:${index}`)
+    );
+  });
 });
diff --git a/src/core/server/saved_objects/export/sort_objects.ts b/src/core/server/saved_objects/export/sort_objects.ts
index 3b73f889933b9..3f9726296dd54 100644
--- a/src/core/server/saved_objects/export/sort_objects.ts
+++ b/src/core/server/saved_objects/export/sort_objects.ts
@@ -8,27 +8,29 @@
 
 import { SavedObject } from '../types';
 
+const getId = (object: { type: string; id: string }) => `${object.type}:${object.id}`;
+
 export function sortObjects(savedObjects: SavedObject[]): SavedObject[] {
-  const path = new Set<SavedObject>();
+  const traversed = new Set<string>();
   const sorted = new Set<SavedObject>();
   const objectsByTypeId = new Map(
-    savedObjects.map((object) => [`${object.type}:${object.id}`, object] as [string, SavedObject])
+    savedObjects.map((object) => [getId(object), object] as [string, SavedObject])
   );
 
   function includeObjects(objects: SavedObject[]) {
     for (const object of objects) {
-      if (path.has(object)) {
+      const objectId = getId(object);
+      if (traversed.has(objectId)) {
         continue;
       }
 
-      const refdObjects = object.references
-        .map((ref) => objectsByTypeId.get(`${ref.type}:${ref.id}`))
+      const objectRefs = object.references
+        .map((ref) => objectsByTypeId.get(getId(ref)))
         .filter((ref): ref is SavedObject => !!ref);
 
-      if (refdObjects.length) {
-        path.add(object);
-        includeObjects(refdObjects);
-        path.delete(object);
+      traversed.add(objectId);
+      if (objectRefs.length) {
+        includeObjects(objectRefs);
       }
 
       sorted.add(object);
@@ -36,5 +38,6 @@ export function sortObjects(savedObjects: SavedObject[]): SavedObject[] {
   }
 
   includeObjects(savedObjects);
+
   return [...sorted];
 }