feat(parser): create info parser with exporting parser internals

packages/parser/tests/info.test.ts

@@ -0,0 +1,58 @@
+import { describe, expect, it } from 'vitest';
+import type { LangiumParser, ParseResult } from 'langium';
+
+import type { InfoServices } from '../src/language/index.js';
+import { Info, createInfoServices } from '../src/language/index.js';
+
+const services: InfoServices = createInfoServices().Info;
+const parser: LangiumParser = services.parser.LangiumParser;
+export function createInfoTestServices(): {
+  services: InfoServices;
+  parse: (input: string) => ParseResult<Info>;
+} {
+  const parse = (input: string) => {
+    return parser.parse<Info>(input);
+  };
+
+  return { services, parse };
+}
+
+describe('info', () => {
+  const { parse } = createInfoTestServices();
+
+  it.each([
+    `info`,
+    `
+    info`,
+    `info
+    `,
+    `
+    info
+    `,
+  ])('should handle empty info', (context: string) => {
+    const { parserErrors, lexerErrors, value } = parse(context);
+    expect(parserErrors).toHaveLength(0);
+    expect(lexerErrors).toHaveLength(0);
+
+    expect(value.$type).toBe(Info);
+  });
+
+  it.each([
+    `info showInfo`,
+    `
+    info showInfo`,
+    `info
+    showInfo
+    `,
+    `
+    info
+    showInfo
+    `,
+  ])('should handle showInfo', (context: string) => {
+    const { parserErrors, lexerErrors, value } = parse(context);
+    expect(parserErrors).toHaveLength(0);
+    expect(lexerErrors).toHaveLength(0);
+
+    expect(value.$type).toBe(Info);
+  });
+});