Table: Fix case where undefined data crashes the visualization (#80498)

.betterer.results

@@ -179,6 +179,9 @@ exports[`better eslint`] = {
     "packages/grafana-data/src/themes/createColors.ts:5381": [
       [0, 0, 0, "Do not use any type assertions.", "0"]
     ],
+    "packages/grafana-data/src/transformations/fieldReducer.test.ts:5381": [
+      [0, 0, 0, "Unexpected any. Specify a different type.", "0"]
+    ],
     "packages/grafana-data/src/transformations/matchers/valueMatchers/types.ts:5381": [
       [0, 0, 0, "Unexpected any. Specify a different type.", "0"],
       [0, 0, 0, "Unexpected any. Specify a different type.", "1"]

packages/grafana-data/src/field/fieldOverrides.test.ts

@@ -124,7 +124,7 @@ describe('Global MinMax', () => {
     });
   });
 
-  describe('when value values are zeo', () => {
+  describe('when values are zero', () => {
     it('then global min max should be correct', () => {
       const frame = toDataFrame({
         fields: [

packages/grafana-data/src/transformations/fieldReducer.test.ts

@@ -3,7 +3,7 @@ import { difference } from 'lodash';
 import { createDataFrame, guessFieldTypeFromValue } from '../dataframe/processDataFrame';
 import { Field, FieldType, NullValueMode } from '../types/index';
 
-import { fieldReducers, ReducerID, reduceField } from './fieldReducer';
+import { fieldReducers, ReducerID, reduceField, defaultCalcs } from './fieldReducer';
 
 /**
  * Run a reducer and get back the value
@@ -63,6 +63,16 @@ describe('Stats Calculators', () => {
     expect(stats.count).toEqual(2);
   });
 
+  it('should handle undefined field data without crashing', () => {
+    // eslint-ignore @typescript-eslint/no-explicit-any
+    const stats = reduceField({
+      field: { name: 'a', values: undefined as any, config: {}, type: FieldType.number },
+      reducers: [ReducerID.first, ReducerID.last, ReducerID.mean, ReducerID.count],
+    });
+
+    expect(stats).toEqual(defaultCalcs);
+  });
+
   it('should support a single stat also', () => {
     basicTable.fields[0].state = undefined; // clear the cache
     const stats = reduceField({

packages/grafana-data/src/transformations/fieldReducer.ts

@@ -84,7 +84,7 @@ export function reduceField(options: ReduceFieldOptions): FieldCalcs {
   // Return early for empty series
   // This lets the concrete implementations assume at least one row
   const data = field.values;
-  if (data.length < 1) {
+  if (data && data.length < 1) {
     const calcs: FieldCalcs = { ...field.state.calcs };
     for (const reducer of queue) {
       calcs[reducer.id] = reducer.emptyInputResult !== null ? reducer.emptyInputResult : null;
@@ -271,33 +271,41 @@ export const fieldReducers = new Registry<FieldReducerInfo>(() => [
   },
 ]);
 
-export function doStandardCalcs(field: Field, ignoreNulls: boolean, nullAsZero: boolean): FieldCalcs {
-  const calcs: FieldCalcs = {
-    sum: 0,
-    max: -Number.MAX_VALUE,
-    min: Number.MAX_VALUE,
-    logmin: Number.MAX_VALUE,
-    mean: null,
-    last: null,
-    first: null,
-    lastNotNull: null,
-    firstNotNull: null,
-    count: 0,
-    nonNullCount: 0,
-    allIsNull: true,
-    allIsZero: true,
-    range: null,
-    diff: null,
-    delta: 0,
-    step: Number.MAX_VALUE,
-    diffperc: 0,
+// Used for test cases
+export const defaultCalcs: FieldCalcs = {
+  sum: 0,
+  max: -Number.MAX_VALUE,
+  min: Number.MAX_VALUE,
+  logmin: Number.MAX_VALUE,
+  mean: null,
+  last: null,
+  first: null,
+  lastNotNull: null,
+  firstNotNull: null,
+  count: 0,
+  nonNullCount: 0,
+  allIsNull: true,
+  allIsZero: true,
+  range: null,
+  diff: null,
+  delta: 0,
+  step: Number.MAX_VALUE,
+  diffperc: 0,
 
-    // Just used for calculations -- not exposed as a stat
-    previousDeltaUp: true,
-  };
+  // Just used for calculations -- not exposed as a stat
+  previousDeltaUp: true,
+};
+
+export function doStandardCalcs(field: Field, ignoreNulls: boolean, nullAsZero: boolean): FieldCalcs {
+  const calcs: FieldCalcs = { ...defaultCalcs };
 
   const data = field.values;
 
+  // early return for undefined / empty series
+  if (!data) {
+    return calcs;
+  }
+
   const isNumberField = field.type === FieldType.number || field.type === FieldType.time;
 
   for (let i = 0; i < data.length; i++) {