[ES|QL] improve SORT command suggestions (#188579)

## Summary

- Suggests options in uppercase
- Applies syntax highlighting

**Before**


https://github.com/user-attachments/assets/5f04d8fc-d61a-4779-906b-a7f4f42b4014

**After**


https://github.com/user-attachments/assets/cd585306-020a-4a55-867a-affe373666f6

---------

Co-authored-by: Stratoula Kalafateli <efstratia.kalafateli@elastic.co>

packages/kbn-esql-validation-autocomplete/src/autocomplete/autocomplete.test.ts

@@ -329,8 +329,8 @@ describe('autocomplete', () => {
       ...getFieldNamesByType('any'),
       ...getFunctionSignaturesByReturnType('sort', 'any', { evalMath: true }),
     ]);
-    testSuggestions('from a | sort stringField ', ['asc', 'desc', ',', '|']);
-    testSuggestions('from a | sort stringField desc ', ['nulls first', 'nulls last', ',', '|']);
+    testSuggestions('from a | sort stringField ', ['ASC', 'DESC', ',', '|']);
+    testSuggestions('from a | sort stringField desc ', ['NULLS FIRST', 'NULLS LAST', ',', '|']);
     // @TODO: improve here
     // testSuggestions('from a | sort stringField desc ', ['first', 'last']);
   });

packages/kbn-esql-validation-autocomplete/src/definitions/commands.ts

@@ -372,8 +372,8 @@ export const commandDefinitions: CommandDefinition[] = [
       multipleParams: true,
       params: [
         { name: 'expression', type: 'any' },
-        { name: 'direction', type: 'string', optional: true, values: ['asc', 'desc'] },
-        { name: 'nulls', type: 'string', optional: true, values: ['nulls first', 'nulls last'] },
+        { name: 'direction', type: 'string', optional: true, values: ['ASC', 'DESC'] },
+        { name: 'nulls', type: 'string', optional: true, values: ['NULLS FIRST', 'NULLS LAST'] },
       ],
     },
   },

packages/kbn-monaco/src/esql/lib/esql_theme.ts

@@ -78,14 +78,13 @@ export const buildESQlTheme = (): monaco.editor.IStandaloneThemeData => ({
         'as',
         'expr_ws',
         'limit',
-        'nulls_ordering_direction',
-        'nulls_ordering',
         'null',
         'enrich',
         'on',
         'with',
         'asc',
         'desc',
+        'nulls_order',
       ],
       euiThemeVars.euiColorAccentText,
       true // isBold

packages/kbn-monaco/src/esql/lib/esql_token_helpers.ts

@@ -13,9 +13,7 @@ function nonNullable<T>(value: T | undefined): value is T {
   return value != null;
 }
 
-export function enrichTokensWithFunctionsMetadata(
-  tokens: monaco.languages.IToken[]
-): monaco.languages.IToken[] {
+export function addFunctionTokens(tokens: monaco.languages.IToken[]): monaco.languages.IToken[] {
   // need to trim spaces as "abs (arg)" is still valid as function
   const myTokensWithoutSpaces = tokens.filter(
     ({ scopes }) => scopes !== 'expr_ws' + ESQL_TOKEN_POSTFIX
@@ -34,3 +32,18 @@ export function enrichTokensWithFunctionsMetadata(
   }
   return [...tokens];
 }
+
+export function addNullsOrder(tokens: monaco.languages.IToken[]): void {
+  const nullsIndex = tokens.findIndex((token) => token.scopes === 'nulls' + ESQL_TOKEN_POSTFIX);
+  if (
+    // did we find a "nulls"?
+    nullsIndex > -1 &&
+    // is the next non-whitespace token an order?
+    ['first' + ESQL_TOKEN_POSTFIX, 'last' + ESQL_TOKEN_POSTFIX].includes(
+      tokens[nullsIndex + 2]?.scopes
+    )
+  ) {
+    tokens[nullsIndex].scopes = 'nulls_order' + ESQL_TOKEN_POSTFIX;
+    tokens.splice(nullsIndex + 1, 2);
+  }
+}

packages/kbn-monaco/src/esql/lib/esql_tokens_provider.ts

@@ -15,7 +15,7 @@ import { ESQLLineTokens } from './esql_line_tokens';
 import { ESQLState } from './esql_state';
 
 import { ESQL_TOKEN_POSTFIX } from './constants';
-import { enrichTokensWithFunctionsMetadata } from './esql_token_helpers';
+import { addFunctionTokens, addNullsOrder } from './esql_token_helpers';
 
 const EOF = -1;
 
@@ -77,7 +77,8 @@ export class ESQLTokensProvider implements monaco.languages.TokensProvider {
     // special treatment for functions
     // the previous custom Kibana grammar baked functions directly as tokens, so highlight was easier
     // The ES grammar doesn't have the token concept of "function"
-    const tokensWithFunctions = enrichTokensWithFunctionsMetadata(myTokens);
+    const tokensWithFunctions = addFunctionTokens(myTokens);
+    addNullsOrder(tokensWithFunctions);
 
     return new ESQLLineTokens(tokensWithFunctions, prevState.getLineNumber() + 1);
   }