Improve error logging from the Language Service

[mizdra]

Summary

I use Volar.js to implement the TypeScript Language Service Plugin. To do this, I have created an object that satisfies import('@volar/language-core').LanguagePlugin<string>. However, I have written code in the LanguagePlugin.getLanguageId function that causes a runtime error.

I would have expected the error to be contained in the tsserver.log. However, it was not actually contained. This made it difficult to determine why the TypeScript Language Service Plugin was not working.

I would like the error to be contained in tsserver.log for debugging.

Reproduction

repository: https://github.com/mizdra/repro-volar-get-language-id-error

/// <reference types="@volar/typescript" />

const ts = require('typescript/lib/tsserverlibrary');

/**
 * @returns {import('@volar/language-core').LanguagePlugin<string>}
 */
exports.createPngLanguagePlugin = function createPngLanguagePlugin() {
  return {
    getLanguageId(scriptId) {
      throw new Error('something wrong'); // cause a runtime error
      if (scriptId.endsWith('.png')) return 'png';
      return undefined;
    },
    createVirtualCode(scriptId, languageId) {
      if (languageId !== 'png') return undefined;
      const dtsContent = `
declare const I_PNG: { src: string, width: number, height: number };
export default I_PNG;
      `.trim();
      return {
        id: 'main',
        languageId: 'png',
        snapshot: {
          getText: (start, end) => dtsContent.slice(start, end),
          getLength: () => dtsContent.length,
          getChangeRange: () => undefined,
        },
        mappings: [],
      };
    },
    typescript: {
      extraFileExtensions: [
        {
          extension: 'png',
          isMixedContent: true,
          scriptKind: ts.ScriptKind.TS,
        },
      ],
      getServiceScript(root) {
        return {
          code: root,
          extension: ts.Extension.Ts,
          scriptKind: ts.ScriptKind.TS,
        };
      },
    },
  };
}

Expected behavior

tsserver.log contains something wrong.

Actual behavior

tsserver.log does not contain something wrong.

Additional context

Functions such as LanguagePlugin.createVirtualCode, LanguagePlugin.typescript.getServiceScript seem to cause similar problems.

[mizdra]

I confirmed that the problem has been fixed. Thank you!