Loki Autocomplete: Suggest only possible labels for unwrap (#61411)

* feat(loki-autocomplete): filter valid labels for unwrap autocomplete suggestions

* refactor(unwrap): reuse new function in builder

public/app/plugins/datasource/loki/LanguageProvider.test.ts

@@ -6,7 +6,11 @@ import { TypeaheadInput } from '@grafana/ui';
 import LanguageProvider, { LokiHistoryItem } from './LanguageProvider';
 import { LokiDatasource } from './datasource';
 import { createLokiDatasource, createMetadataRequest } from './mocks';
-import { extractLogParserFromDataFrame, extractLabelKeysFromDataFrame } from './responseUtils';
+import {
+  extractLogParserFromDataFrame,
+  extractLabelKeysFromDataFrame,
+  extractUnwrapLabelKeysFromDataFrame,
+} from './responseUtils';
 import { LokiQueryType } from './types';
 
 jest.mock('./responseUtils');
@@ -304,11 +308,13 @@ describe('Query imports', () => {
     let datasource: LokiDatasource, languageProvider: LanguageProvider;
     const extractLogParserFromDataFrameMock = jest.mocked(extractLogParserFromDataFrame);
     const extractedLabelKeys = ['extracted', 'label'];
+    const unwrapLabelKeys = ['unwrap', 'labels'];
 
     beforeEach(() => {
       datasource = createLokiDatasource();
       languageProvider = new LanguageProvider(datasource);
       jest.mocked(extractLabelKeysFromDataFrame).mockReturnValue(extractedLabelKeys);
+      jest.mocked(extractUnwrapLabelKeysFromDataFrame).mockReturnValue(unwrapLabelKeys);
     });
 
     it('identifies selectors with JSON parser data', async () => {
@@ -317,6 +323,7 @@ describe('Query imports', () => {
 
       expect(await languageProvider.getParserAndLabelKeys('{place="luna"}')).toEqual({
         extractedLabelKeys,
+        unwrapLabelKeys,
         hasJSON: true,
         hasLogfmt: false,
       });
@@ -328,6 +335,7 @@ describe('Query imports', () => {
 
       expect(await languageProvider.getParserAndLabelKeys('{place="luna"}')).toEqual({
         extractedLabelKeys,
+        unwrapLabelKeys,
         hasJSON: false,
         hasLogfmt: true,
       });
@@ -339,6 +347,7 @@ describe('Query imports', () => {
 
       expect(await languageProvider.getParserAndLabelKeys('{place="luna"}')).toEqual({
         extractedLabelKeys: [],
+        unwrapLabelKeys: [],
         hasJSON: false,
         hasLogfmt: false,
       });