Prometheus: Fuzzy search for metric names in Code Mode (#85396)

* perf: limit metric names in Code Mode suggestions

* feat: configurable metric names limit

* feat: code mode autocomplete info/disclaimer

* chore: put new functionality behind new feature toggle

* refactor: avoid type assertions

* refactor: avoid explicit `any`

refactor: type guards

* refactor: type guards

* chore: add testdata results

* fix: add missing feature toggle guard

* perf: prefer array access to `Array.prototype.at`

* test: add missing config override

* test: refactor for brevity & clarity

* perf: avoid unnecessary mapping

* chore: undo testdata changes

* fix: use correct limit; perf optimizations

* refactor: avoid unnecessary `async`s

* types: simplify

* test: add missing tests

* fix: avoid hardcoding

* test: update mock path

* docs: fix typo

style: remove formatting artifact

style: remove formatting artifact

style: remove formatting artifact

* fix: event scope regression

* style: refactor for clarity

* refactor: prefer `useCallback` to in-effect handler

* refactor: simplify & broaden `filter`

* refactor: rename file to keep with conventions

* chore: mirror Prometheus package changes in app

* refactor: prefer no `@ts-ignore`

* chore: update betterer results

* docs: use type in TSDoc `@link` without `@ts-ignore`

* test: add missing provider

* test: fix jest mock path

* fix: display disclaimer in empty input case

pkg/services/featuremgmt/registry.go

@@ -859,6 +859,13 @@ var (
 			FrontendOnly: true,
 			Owner:        grafanaObservabilityMetricsSquad,
 		},
+		{
+			Name:         "prometheusCodeModeMetricNamesSearch",
+			Description:  "Enables search for metric names in Code Mode, to improve performance when working with an enormous number of metric names",
+			FrontendOnly: true,
+			Stage:        FeatureStageExperimental,
+			Owner:        grafanaObservabilityMetricsSquad,
+		},
 		{
 			Name:         "addFieldFromCalculationStatFunctions",
 			Description:  "Add cumulative and window functions to the add field from calculation transformation",

pkg/services/featuremgmt/toggles_gen.csv

@@ -114,6 +114,7 @@ cachingOptimizeSerializationMemoryUsage,experimental,@grafana/grafana-operator-e
 panelTitleSearchInV1,experimental,@grafana/backend-platform,true,false,false
 managedPluginsInstall,GA,@grafana/plugins-platform-backend,false,false,false
 prometheusPromQAIL,experimental,@grafana/observability-metrics,false,false,true
+prometheusCodeModeMetricNamesSearch,experimental,@grafana/observability-metrics,false,false,true
 addFieldFromCalculationStatFunctions,preview,@grafana/dataviz-squad,false,false,true
 alertmanagerRemoteSecondary,experimental,@grafana/alerting-squad,false,false,false
 alertmanagerRemotePrimary,experimental,@grafana/alerting-squad,false,false,false

pkg/services/featuremgmt/toggles_gen.go

@@ -467,6 +467,10 @@ const (
 	// Prometheus and AI/ML to assist users in creating a query
 	FlagPrometheusPromQAIL = "prometheusPromQAIL"
 
+	// FlagPrometheusCodeModeMetricNamesSearch
+	// Enables search for metric names in Code Mode, to improve performance when working with an enormous number of metric names
+	FlagPrometheusCodeModeMetricNamesSearch = "prometheusCodeModeMetricNamesSearch"
+
 	// FlagAddFieldFromCalculationStatFunctions
 	// Add cumulative and window functions to the add field from calculation transformation
 	FlagAddFieldFromCalculationStatFunctions = "addFieldFromCalculationStatFunctions"

pkg/services/featuremgmt/toggles_gen.json

@@ -2107,6 +2107,19 @@
         "hideFromAdminPage": true,
         "hideFromDocs": true
       }
+    },
+    {
+      "metadata": {
+        "name": "prometheusCodeModeMetricNamesSearch",
+        "resourceVersion": "1712241392690",
+        "creationTimestamp": "2024-04-04T14:36:32Z"
+      },
+      "spec": {
+        "description": "Enables search for metric names in Code Mode, to improve performance when working with an enormous number of metric names",
+        "stage": "experimental",
+        "codeowner": "@grafana/observability-metrics",
+        "frontend": true
+      }
     }
   ]
 }