Prometheus: Add native histogram functions (#86002)

* add native histogram functions to code editor

* add native histogram function types for query builder

* add functions to query builder

* add test to show parsing breaks from code to builder

* add histogram_avg to code editor

* add histogram_avg to builder and make parity between package and core

* add functions to hard coded promql file for highlighting

* remove native histogram test so that it can be added in #85942

* remove functions from core prometheus js to prevent merge conflict in #86080

* use xit for test instead of removing it

packages/grafana-prometheus/src/components/monaco-query-field/promql.ts

@@ -84,6 +84,12 @@ const functions = [
   'exp',
   'floor',
   'histogram_quantile',
+  'histogram_avg',
+  'histogram_count',
+  'histogram_sum',
+  'histogram_fraction',
+  'histogram_stddev',
+  'histogram_stdvar',
   'holt_winters',
   'hour',
   'idelta',

packages/grafana-prometheus/src/promql.ts

@@ -534,6 +534,44 @@ export const FUNCTIONS = [
     detail: 'present_over_time(range-vector)',
     documentation: 'The value 1 for any series in the specified interval.',
   },
+  {
+    insertText: 'histogram_avg',
+    label: 'histogram_avg',
+    detail: 'histogram_avg(v instant-vector)',
+    documentation:
+      'Returns the arithmetic average of observed values stored in a native histogram. Samples that are not native histograms are ignored and do not show up in the returned vector.',
+  },
+  {
+    insertText: 'histogram_count',
+    label: 'histogram_count',
+    detail: 'histogram_count(v instant-vector)',
+    documentation: 'Returns the count of observations stored in a native histogram.',
+  },
+  {
+    insertText: 'histogram_sum',
+    label: 'histogram_sum',
+    detail: 'histogram_sum(v instant-vector)',
+    documentation: 'Returns the sum of observations stored in a native histogram.',
+  },
+  {
+    insertText: 'histogram_fraction',
+    label: 'histogram_fraction',
+    detail: 'histogram_fraction(lower scalar, upper scalar, v instant-vector)',
+    documentation: 'Returns the estimated fraction of observations between the provided lower and upper values.',
+  },
+  {
+    insertText: 'histogram_stddev',
+    label: 'histogram_stddev',
+    detail: 'histogram_stddev(v instant-vector)',
+    documentation:
+      'Returns the estimated standard deviation of observations in a native histogram, based on the geometric mean of the buckets where the observations lie.',
+  },
+  {
+    insertText: 'histogram_stdvar',
+    label: 'histogram_stdvar',
+    detail: 'histogram_stdvar(v instant-vector)',
+    documentation: 'Returns the estimated standard variance of observations in a native histogram.',
+  },
 ];
 
 export const PROM_KEYWORDS = FUNCTIONS.map((keyword) => keyword.label);

packages/grafana-prometheus/src/querybuilder/operations.ts

@@ -28,6 +28,23 @@ export function getOperationDefinitions(): QueryBuilderOperationDef[] {
       renderer: functionRendererLeft,
       addOperationHandler: defaultAddOperationHandler,
     },
+    createFunction({ id: PromOperationId.HistogramAvg }),
+    createFunction({ id: PromOperationId.HistogramCount }),
+    createFunction({ id: PromOperationId.HistogramSum }),
+    {
+      id: PromOperationId.HistogramFraction,
+      name: 'Histogram fraction',
+      params: [
+        { name: 'Lower scalar', type: 'number' },
+        { name: 'Upper scalar', type: 'number' },
+      ],
+      defaultParams: [0.0, 0.2],
+      category: PromVisualQueryOperationCategory.Functions,
+      renderer: functionRendererLeft,
+      addOperationHandler: defaultAddOperationHandler,
+    },
+    createFunction({ id: PromOperationId.HistogramStddev }),
+    createFunction({ id: PromOperationId.HistogramStdvar }),
     {
       id: PromOperationId.LabelReplace,
       name: 'Label replace',

packages/grafana-prometheus/src/querybuilder/parsing.test.ts

@@ -290,6 +290,28 @@ describe('buildVisualQueryFromString', () => {
     });
   });
 
+  // enable in #85942 when updated lezer parser is merged
+  xit('parses a native histogram function correctly', () => {
+    expect(
+      buildVisualQueryFromString('histogram_count(rate(counters_logins{app="backend"}[$__rate_interval]))')
+    ).toEqual({
+      errors: [],
+      query: {
+        metric: 'counters_logins',
+        labels: [{ label: 'app', op: '=', value: 'backend' }],
+        operations: [
+          {
+            id: 'rate',
+            params: ['$__rate_interval'],
+          },
+          {
+            id: 'histogram_quantile',
+          },
+        ],
+      },
+    });
+  });
+
   it('parses function with multiple arguments', () => {
     expect(
       buildVisualQueryFromString(

packages/grafana-prometheus/src/querybuilder/types.ts

@@ -63,6 +63,12 @@ export enum PromOperationId {
   Floor = 'floor',
   Group = 'group',
   HistogramQuantile = 'histogram_quantile',
+  HistogramAvg = 'histogram_avg',
+  HistogramCount = 'histogram_count',
+  HistogramSum = 'histogram_sum',
+  HistogramFraction = 'histogram_fraction',
+  HistogramStddev = 'histogram_stddev',
+  HistogramStdvar = 'histogram_stdvar',
   HoltWinters = 'holt_winters',
   Hour = 'hour',
   Idelta = 'idelta',