DataFrame: Add meta indicating comparison series (#71129)

* DataFrame: Add meta indicating comparison series

* Update metadata type

* Update test

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

@@ -15,6 +15,47 @@ function checkScenario(scenario: TitleScenario): string {
   return getFieldDisplayName(field, frame, scenario.frames);
 }
 
+describe('getFieldDisplayName', () => {
+  it('Should add suffix for comparison frames', () => {
+    const frame = toDataFrame({
+      meta: {
+        timeCompare: {
+          diffMs: -86400000,
+          isTimeShiftQuery: true,
+        },
+      },
+      fields: [
+        { name: TIME_SERIES_TIME_FIELD_NAME, values: [1, 2, 3], type: FieldType.time },
+        {
+          name: 'Value 1',
+          values: [1, 2, 3],
+          type: FieldType.number,
+          config: {
+            displayName: 'ServerA',
+          },
+        },
+        {
+          name: 'Value 2',
+          values: [1, 2, 3],
+          type: FieldType.number,
+          config: {
+            displayNameFromDS: 'ServerB',
+          },
+        },
+        {
+          name: 'Value 3',
+          values: [1, 2, 3],
+          type: FieldType.number,
+        },
+      ],
+    });
+
+    expect(getFieldDisplayName(frame.fields[1], frame)).toBe('ServerA (comparison)');
+    expect(getFieldDisplayName(frame.fields[2], frame)).toBe('ServerB (comparison)');
+    expect(getFieldDisplayName(frame.fields[3], frame)).toBe('Value 3 (comparison)');
+  });
+});
+
 describe('getFrameDisplayName', () => {
   it('Should return frame name if set', () => {
     const frame = toDataFrame({

packages/grafana-data/src/field/fieldState.ts

@@ -72,15 +72,15 @@ export function getFieldDisplayName(field: Field, frame?: DataFrame, allFrames?:
  */
 export function calculateFieldDisplayName(field: Field, frame?: DataFrame, allFrames?: DataFrame[]): string {
   const hasConfigTitle = field.config?.displayName && field.config?.displayName.length;
-
+  const isComparisonSeries = Boolean(frame?.meta?.timeCompare?.isTimeShiftQuery);
   let displayName = hasConfigTitle ? field.config!.displayName! : field.name;
 
   if (hasConfigTitle) {
-    return displayName;
+    return isComparisonSeries ? `${displayName} (comparison)` : displayName;
   }
 
   if (frame && field.config?.displayNameFromDS) {
-    return field.config.displayNameFromDS;
+    return isComparisonSeries ? `${field.config.displayNameFromDS} (comparison)` : field.config.displayNameFromDS;
   }
 
   // This is an ugly exception for time field
@@ -151,6 +151,9 @@ export function calculateFieldDisplayName(field: Field, frame?: DataFrame, allFr
     displayName = getUniqueFieldName(field, frame);
   }
 
+  if (isComparisonSeries) {
+    displayName = `${displayName} (comparison)`;
+  }
   return displayName;
 }
 

packages/grafana-data/src/types/data.ts

@@ -94,6 +94,12 @@ export interface QueryResultMeta {
    */
   pathSeparator?: string;
 
+  /** A time shift metadata indicating a result of comparison */
+  timeCompare?: {
+    diffMs: number;
+    isTimeShiftQuery: boolean;
+  };
+
   /**
    * Legacy data source specific, should be moved to custom
    * */