prometheus: monaco: do not show automatic suggestions (#41253)

* prometheus: monaco: do not show automatic suggestions

* updated comments

public/app/plugins/datasource/prometheus/components/monaco-query-field/MonacoQueryField.tsx

@@ -4,7 +4,7 @@ import { GrafanaTheme2 } from '@grafana/data';
 import { css } from '@emotion/css';
 import { useLatest } from 'react-use';
 import { promLanguageDefinition } from 'monaco-promql';
-import { getCompletionProvider } from './monaco-completion-provider';
+import { getCompletionProvider, getSuggestOptions } from './monaco-completion-provider';
 import { Props } from './MonacoQueryFieldProps';
 import { getOverrideServices } from './getOverrideServices';
 
@@ -35,6 +35,7 @@ const options: monacoTypes.editor.IStandaloneEditorConstructionOptions = {
     horizontalScrollbarSize: 0,
   },
   scrollBeyondLastLine: false,
+  suggest: getSuggestOptions(),
   suggestFontSize: 12,
   wordWrap: 'on',
 };

public/app/plugins/datasource/prometheus/components/monaco-query-field/monaco-completion-provider/index.ts

@@ -4,6 +4,27 @@ import { getSituation } from './situation';
 import { getCompletions, DataProvider, CompletionType } from './completions';
 import { NeverCaseError } from './util';
 
+export function getSuggestOptions(): monacoTypes.editor.ISuggestOptions {
+  return {
+    // monaco-editor sometimes provides suggestions automatically, i am not
+    // sure based on what, seems to be by analyzing the words already
+    // written.
+    // to try it out:
+    // - enter `go_goroutines{job~`
+    // - have the cursor at the end of the string
+    // - press ctrl-enter
+    // - you will get two suggestions
+    // those were not provided by grafana, they are offered automatically.
+    // i want to remove those. the only way i found is:
+    // - every suggestion-item has a `kind` attribute,
+    //   that controls the icon to the left of the suggestion.
+    // - items auto-generated by monaco have `kind` set to `text`.
+    // - we make sure grafana-provided suggestions do not have `kind` set to `text`.
+    // - and then we tell monaco not to show suggestions of kind `text`
+    showWords: false,
+  };
+}
+
 function getMonacoCompletionItemKind(type: CompletionType, monaco: Monaco): monacoTypes.languages.CompletionItemKind {
   switch (type) {
     case 'DURATION':