From 970dcdf723142c762e224a8821b3a8e1441de46e Mon Sep 17 00:00:00 2001
From: Josh Romero <rmerqg@amazon.com>
Date: Thu, 29 Dec 2022 21:20:59 +0000
Subject: [PATCH 1/2] [Feature] Allow order control in `createAggConfig`

Add new optional boolean param that adds the new `AggConfig` to the beginning of the array rather than the end.
Makes it easier to work with Pie or other visualizations with `Schemas` that set `mustBeFirst`

Signed-off-by: Josh Romero <rmerqg@amazon.com>
---
 .../common/search/aggs/agg_configs.test.ts    | 52 ++++++++++++++++++-
 .../data/common/search/aggs/agg_configs.ts    | 10 ++--
 2 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/src/plugins/data/common/search/aggs/agg_configs.test.ts b/src/plugins/data/common/search/aggs/agg_configs.test.ts
index 076fbd9de3d7..583c73a2724a 100644
--- a/src/plugins/data/common/search/aggs/agg_configs.test.ts
+++ b/src/plugins/data/common/search/aggs/agg_configs.test.ts
@@ -117,7 +117,7 @@ describe('AggConfigs', () => {
       expect(ac.aggs).toHaveLength(3);
     });
 
-    it('adds new AggConfig entries to AggConfigs by default', () => {
+    it('adds new AggConfig entries to end of AggConfigs by default', () => {
       const configStates = [
         {
           enabled: true,
@@ -136,6 +136,7 @@ describe('AggConfigs', () => {
         schema: 'split',
       });
       expect(ac.aggs).toHaveLength(2);
+      expect(ac.aggs[1].schema).toBe('split');
     });
 
     it('does not add an agg to AggConfigs if addToAggConfigs: false', () => {
@@ -161,6 +162,55 @@ describe('AggConfigs', () => {
       );
       expect(ac.aggs).toHaveLength(1);
     });
+
+    it('adds new AggConfig entries to beginning of AggConfigs if mustBeFirst: true', () => {
+      const configStates = [
+        {
+          enabled: true,
+          type: 'histogram',
+          params: {},
+        },
+      ];
+
+      const ac = new AggConfigs(indexPattern, configStates, { typesRegistry });
+      expect(ac.aggs).toHaveLength(1);
+
+      ac.createAggConfig(
+        {
+          enabled: true,
+          type: 'terms',
+          params: {},
+          schema: 'split',
+        },
+        { mustBeFirst: true }
+      );
+      expect(ac.aggs).toHaveLength(2);
+      expect(ac.aggs[0].schema).toBe('split');
+    });
+
+    it('does not add an agg to AggConfigs if addToAggConfigs: false and mustBeFirst: true', () => {
+      const configStates = [
+        {
+          enabled: true,
+          type: 'histogram',
+          params: {},
+        },
+      ];
+
+      const ac = new AggConfigs(indexPattern, configStates, { typesRegistry });
+      expect(ac.aggs).toHaveLength(1);
+
+      ac.createAggConfig(
+        {
+          enabled: true,
+          type: 'terms',
+          params: {},
+          schema: 'split',
+        },
+        { addToAggConfigs: false, mustBeFirst: true }
+      );
+      expect(ac.aggs).toHaveLength(1);
+    });
   });
 
   describe('#getRequestAggs', () => {
diff --git a/src/plugins/data/common/search/aggs/agg_configs.ts b/src/plugins/data/common/search/aggs/agg_configs.ts
index 90ad5820ea3c..8f13fcd54f0e 100644
--- a/src/plugins/data/common/search/aggs/agg_configs.ts
+++ b/src/plugins/data/common/search/aggs/agg_configs.ts
@@ -130,10 +130,10 @@ export class AggConfigs {
 
   createAggConfig = <T extends AggConfig = AggConfig>(
     params: CreateAggConfigParams,
-    { addToAggConfigs = true } = {}
+    { addToAggConfigs = true, mustBeFirst = false } = {}
   ) => {
     const { type } = params;
-    let aggConfig;
+    let aggConfig: AggConfig;
 
     if (params instanceof AggConfig) {
       aggConfig = params;
@@ -145,8 +145,12 @@ export class AggConfigs {
       });
     }
 
+    const addAggConfig = () => {
+      return mustBeFirst ? this.aggs.unshift(aggConfig) : this.aggs.push(aggConfig);
+    };
+
     if (addToAggConfigs) {
-      this.aggs.push(aggConfig);
+      addAggConfig();
     }
 
     return aggConfig as T;

From 1b6f69f2600269d73f54cf1d32e1a48ec2623996 Mon Sep 17 00:00:00 2001
From: Josh Romero <rmerqg@amazon.com>
Date: Thu, 29 Dec 2022 21:29:19 +0000
Subject: [PATCH 2/2] [Chore] Add changelog

Signed-off-by: Josh Romero <rmerqg@amazon.com>
---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cb4fd806d9e5..1be6108397eb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -51,6 +51,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - [Doc] Add current plugin persistence implementation readme ([#3081](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3081))
 - [Table Visualization] Refactor table visualization using React and DataGrid component ([#2863](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/2863))
 - [Vis Builder] Add redux store persistence ([#3088](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3088))
+- [Data] Update `createAggConfig` so that newly created configs can be added to beginning of `aggConfig` array ([#3160](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/3160))
 
 ### 🐛 Bug Fixes