From 448784222780d35939a465c8c6a5e80807170beb Mon Sep 17 00:00:00 2001
From: "Grot (@grafanabot)" <43478413+grafanabot@users.noreply.github.com>
Date: Wed, 25 May 2022 05:52:54 -0400
Subject: [PATCH] Transformations: Add an All Unique Values Reducer (#48653)
 (#48733)

(cherry picked from commit 570ff074f6fc83663e35ed57b54ed7f825d38553)

Co-authored-by: Josiah (Jay) Goodson <josiah.goodson@gmail.com>
---
 .../src/transformations/fieldReducer.test.ts           |  9 +++++++++
 .../grafana-data/src/transformations/fieldReducer.ts   | 10 ++++++++++
 2 files changed, 19 insertions(+)

diff --git a/packages/grafana-data/src/transformations/fieldReducer.test.ts b/packages/grafana-data/src/transformations/fieldReducer.test.ts
index 243479b7f2d..34de7c94f90 100644
--- a/packages/grafana-data/src/transformations/fieldReducer.test.ts
+++ b/packages/grafana-data/src/transformations/fieldReducer.test.ts
@@ -97,6 +97,15 @@ describe('Stats Calculators', () => {
     expect(stats.delta).toEqual(300);
   });
 
+  it('should calculate unique values', () => {
+    const stats = reduceField({
+      field: createField('x', [1, 2, 2, 3, 1]),
+      reducers: [ReducerID.uniqueValues],
+    });
+
+    expect(stats.uniqueValues).toEqual([1, 2, 3]);
+  });
+
   it('consistently check allIsNull/allIsZero', () => {
     const empty = createField('x');
     const allNull = createField('x', [null, null, null, null]);
diff --git a/packages/grafana-data/src/transformations/fieldReducer.ts b/packages/grafana-data/src/transformations/fieldReducer.ts
index aaf400ba105..c593ac47346 100644
--- a/packages/grafana-data/src/transformations/fieldReducer.ts
+++ b/packages/grafana-data/src/transformations/fieldReducer.ts
@@ -25,6 +25,7 @@ export enum ReducerID {
   allIsZero = 'allIsZero',
   allIsNull = 'allIsNull',
   allValues = 'allValues',
+  uniqueValues = 'uniqueValues',
 }
 
 // Internal function
@@ -237,6 +238,15 @@ export const fieldReducers = new Registry<FieldReducerInfo>(() => [
     standard: false,
     reduce: (field: Field) => ({ allValues: field.values.toArray() }),
   },
+  {
+    id: ReducerID.uniqueValues,
+    name: 'All unique values',
+    description: 'Returns an array with all unique values',
+    standard: false,
+    reduce: (field: Field) => ({
+      uniqueValues: [...new Set(field.values.toArray())],
+    }),
+  },
 ]);
 
 export function doStandardCalcs(field: Field, ignoreNulls: boolean, nullAsZero: boolean): FieldCalcs {