From 633e354a76f02c9d8c26e930b30df0676f2fd70f Mon Sep 17 00:00:00 2001
From: Galen Kistler <109082771+gtk-grafana@users.noreply.github.com>
Date: Thu, 8 Feb 2024 11:29:10 -0600
Subject: [PATCH] Transformations: Fix converting time fields to number in
 reduceFields (#81830)

* Fix bug converting time fields to number in reduce
---------

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>
---
 .../transformers/reduce.test.ts               | 30 +++++++++++++++++--
 .../transformations/transformers/reduce.ts    | 20 +++++++++++--
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/packages/grafana-data/src/transformations/transformers/reduce.test.ts b/packages/grafana-data/src/transformations/transformers/reduce.test.ts
index 95c175f66a0..3cb46763a54 100644
--- a/packages/grafana-data/src/transformations/transformers/reduce.test.ts
+++ b/packages/grafana-data/src/transformations/transformers/reduce.test.ts
@@ -21,7 +21,7 @@ const seriesAWithMultipleFields = toDataFrame({
   name: 'A',
   fields: [
     { name: 'time', type: FieldType.time, values: [3000, 4000, 5000, 6000] },
-    { name: 'temperature', type: FieldType.number, values: [3, 4, 5, 6] },
+    { name: 'temperature', type: FieldType.number, values: [3, 4, 5, 6, 6] },
     { name: 'humidity', type: FieldType.number, values: [10000.3, 10000.4, 10000.5, 10000.6] },
   ],
 });
@@ -52,7 +52,14 @@ describe('Reducer Transformer', () => {
     const cfg = {
       id: DataTransformerID.reduce,
       options: {
-        reducers: [ReducerID.first, ReducerID.min, ReducerID.max, ReducerID.last],
+        reducers: [
+          ReducerID.first,
+          ReducerID.min,
+          ReducerID.max,
+          ReducerID.last,
+          ReducerID.uniqueValues,
+          ReducerID.count,
+        ],
       },
     };
 
@@ -90,6 +97,25 @@ describe('Reducer Transformer', () => {
             values: [6, 10000.6, 7, 11000.7],
             config: {},
           },
+          {
+            // expect type other
+            name: 'All unique values',
+            type: FieldType.other,
+            values: [
+              [3, 4, 5, 6],
+              [10000.3, 10000.4, 10000.5, 10000.6],
+              [1, 3, 5, 7],
+              [11000.1, 11000.3, 11000.5, 11000.7],
+            ],
+            config: {},
+          },
+          {
+            // expect type number
+            name: 'Count',
+            type: FieldType.number,
+            values: [5, 4, 4, 4],
+            config: {},
+          },
         ];
 
         expect(processed.length).toEqual(1);
diff --git a/packages/grafana-data/src/transformations/transformers/reduce.ts b/packages/grafana-data/src/transformations/transformers/reduce.ts
index 1294903e83d..f8ba7adddc5 100644
--- a/packages/grafana-data/src/transformations/transformers/reduce.ts
+++ b/packages/grafana-data/src/transformations/transformers/reduce.ts
@@ -1,6 +1,6 @@
 import { map } from 'rxjs/operators';
 
-import { guessFieldTypeForField, guessFieldTypeFromValue } from '../../dataframe/processDataFrame';
+import { guessFieldTypeForField } from '../../dataframe/processDataFrame';
 import { getFieldDisplayName } from '../../field';
 import { KeyValue } from '../../types/data';
 import { DataFrame, Field, FieldType } from '../../types/dataFrame';
@@ -211,7 +211,6 @@ export function reduceFields(data: DataFrame[], matcher: FieldMatcher, reducerId
   const calculators = fieldReducers.list(reducerId);
   const reducers = calculators.map((c) => c.id);
   const processed: DataFrame[] = [];
-
   for (const series of data) {
     const fields: Field[] = [];
     for (const field of series.fields) {
@@ -224,7 +223,7 @@ export function reduceFields(data: DataFrame[], matcher: FieldMatcher, reducerId
           const value = results[reducer];
           const copy = {
             ...field,
-            type: guessFieldTypeFromValue(value),
+            type: getFieldType(reducer, field),
             values: [value],
           };
           copy.state = undefined;
@@ -249,3 +248,18 @@ export function reduceFields(data: DataFrame[], matcher: FieldMatcher, reducerId
 
   return processed;
 }
+
+function getFieldType(reducer: string, field: Field) {
+  switch (reducer) {
+    case ReducerID.allValues:
+    case ReducerID.uniqueValues:
+      return FieldType.other;
+    case ReducerID.first:
+    case ReducerID.firstNotNull:
+    case ReducerID.last:
+    case ReducerID.lastNotNull:
+      return field.type;
+    default:
+      return FieldType.number;
+  }
+}