define an enum for different language supported

Signed-off-by: Augustin Husson <[email protected]>

src/app/app.ts

@@ -23,16 +23,23 @@
 import { basicSetup } from '@codemirror/basic-setup';
 import { EditorState } from '@codemirror/state';
 import { EditorView } from '@codemirror/view';
-import { PromQLExtension } from '../lang-promql';
+import { LanguageType, PromQLExtension } from '../lang-promql';
 import { customTheme, promQLHighlightMaterialTheme } from './theme';
 
 const promqlExtension = new PromQLExtension();
 let editor: EditorView;
 
-function getFullLanguage(): boolean {
+function getFullLanguage(): LanguageType {
   const completionSelect = document.getElementById('fullLanguage') as HTMLSelectElement;
   const completionValue = completionSelect.options[completionSelect.selectedIndex].value;
-  return completionValue === 'promql';
+  switch (completionValue) {
+    case 'promql':
+      return LanguageType.PromQL;
+    case 'metricName':
+      return LanguageType.MetricName;
+    default:
+      return LanguageType.PromQL;
+  }
 }
 
 function setCompletion() {

src/lang-promql/index.ts

@@ -23,4 +23,4 @@
 export { PrometheusClient } from './client';
 export { CompleteConfiguration, CompleteStrategy } from './complete';
 export { LintStrategy } from './lint';
-export { PromQLExtension } from './promql';
+export { PromQLExtension, LanguageType } from './promql';

src/lang-promql/promql.ts

@@ -28,7 +28,12 @@ import { LintStrategy, newLintStrategy, promQLLinter } from './lint';
 import { CompletionContext } from '@codemirror/autocomplete';
 import { LezerLanguage } from '@codemirror/language';
 
-function promQLLanguage(top: string) {
+export enum LanguageType {
+  PromQL = 'PromQL',
+  MetricName = 'MetricName',
+}
+
+function promQLLanguage(top: LanguageType) {
   return LezerLanguage.define({
     parser: parser.configure({
       top: top,
@@ -105,9 +110,8 @@ export class PromQLExtension {
     return this;
   }
 
-  asExtension(fullPromQLLanguage = true): Extension {
-    const top = fullPromQLLanguage ? 'PromQL' : 'MetricName';
-    const language = promQLLanguage(top);
+  asExtension(languageType = LanguageType.PromQL): Extension {
+    const language = promQLLanguage(languageType);
     let extension: Extension = [language];
     if (this.enableCompletion) {
       const completion = language.data.of({