取消注释未使用的autoSuggest方法后Monaco Web Editor功能失效求助

我在给Monaco Web Editor添加代码提示功能时遇到异常：即使autoSuggest方法未被主动调用，编辑器的语法着色、格式化、错误高亮等核心功能全部失效；但如果把autoSuggest简化为直接返回空建议列表，所有核心功能又能正常运行（仅无代码提示）。

有问题的TodoLangLanguageService完整代码 #

import { ExpressionContext } from "../ANTLR/ExpressionsParserGrammarParser";

import * as monaco from "monaco-editor-core";
import { ILanguageError } from "../todo-lang/ILanguageError";
import { calcFormatted } from "../todo-lang/FormatterVisitor";
import { parseAndGetASTRoot, parseAndGetSyntaxErrors } from "../todo-lang/parser";


export default class TodoLangLanguageService {
    validate(code: string): ILanguageError[] {
        const syntaxErrors: ILanguageError[] = parseAndGetSyntaxErrors(code);
        const ast: ExpressionContext = parseAndGetASTRoot(code);
        return syntaxErrors;//.concat(checkSemanticRules(ast));
    }
    format(code: string): string {
        return calcFormatted(code).value
    }

    autoSuggest(code: string, line: number, charPosInLine: number): monaco.languages.CompletionList {

        const syntaxErrors: ILanguageError[] = parseAndGetSyntaxErrors(code);
        let completeonItems: Array<monaco.languages.CompletionItem> = syntaxErrors.filter(err => err.startLineNumber == line && err.startColumn == charPosInLine).map(e => {
            let ci: monaco.languages.CompletionItem = {

                label: e.message,
                /**
                 * The kind of this completion item. Based on the kind
                 * an icon is chosen by the editor.
                 */
                kind: monaco.languages.CompletionItemKind.Field,

                insertText: e.message,
                range: {
                    /**
                     * Line number on which the range starts (starts at 1).
                    */
                    startLineNumber: e.startLineNumber,
                    /**
                     * Column on which the range starts in line `startLineNumber` (starts at 1).
                     */
                    startColumn: e.startColumn,
                    /**
                     * Line number on which the range ends.
                     */
                    endLineNumber: e.endLineNumber,
                    /**
                     * Column on which the range ends in line `endLineNumber`.
                     */
                    endColumn: e.endColumn
                }
            }
            return ci;
        })

        let ci:monaco.languages.CompletionList={
            suggestions:completeonItems
        }
        return ci;
    }
}

可正常运行的简化版autoSuggest方法 #

autoSuggest(code: string, line: number, charPosInLine: number): monaco.languages.CompletionList {
    const syntaxErrors: ILanguageError[] = parseAndGetSyntaxErrors(code);
    
    let ci:monaco.languages.CompletionList={
        suggestions:[]
    }
    
    return ci;
}

项目package.json配置 #

{
  "name": "todolangeditor",
  "version": "1.0.0",
  "description": "TodoLang editor",
  "scripts": {
    "start": "webpack-dev-server --hot --open",
   "antlr4ts": "antlr4ts ./ExpressionsParserGrammar.g4 -visitor -o ./src/ANTLR"
  },
  "author": "Open",
  "license": "ISC",
  "dependencies": {
    "antlr4ts": "^0.5.0-alpha.3",
    "monaco-editor-core": "^0.18.1",
    "react": "^16.8.6",
    "react-dom": "^16.8.6"
  },
  "devDependencies": {
    "@types/react": "^16.8.12",
    "@types/react-dom": "^16.8.3",
    "antlr4ts-cli": "^0.5.0-alpha.3",
    "css-loader": "^3.3.0",
    "html-webpack-plugin": "^3.2.0",
    "style-loader": "^1.0.1",
    "ts-loader": "^5.3.3",
    "typescript": "^3.4.2",
    "webpack": "^4.29.6",
    "webpack-cli": "^3.3.0",
    "webpack-dev-server": "^3.2.1"
  }
}

npm install执行日志（仅警告） #

npm WARN deprecated set-value@2.0.0: Critical bug fixed in v3.0.1,please upgrade to the latest version.
npm WARN deprecated set-value@0.4.3: Critical bug fixed in v3.0.1, please upgrade to the latest version.
npm WARN deprecated urix@0.1.0: Please see deprecated notice.
npm WARN deprecated chokidar@2.1.8: Chokidar 2 does not receive security updates since 2019. Upgrade to chokidar 3 with 15x fewer dependencies
npm WARN deprecated chokidar@2.1.8: Chokidar 2 does not receive security updates since 2019. Upgrade to chokidar 3 with 15x fewer dependencies
npm WARN deprecated resolve-url@0.2.1: deprecated notice.
npm WARN deprecated source-map-url@0.4.0: See deprecated notice.
npm WARN deprecated html-webpack-plugin@3.2.0: 3.x is no longer supported
npm WARN deprecated querystring@0.2.0: The querystring API is considered Legacy. new code should use the URLSearchParams API instead.
npm WARN deprecated uuid@3.4.0: Please upgrade to version 7 or higher. Older versions may use Math.random() in certain circumstances, which is known to be problematic.
npm WARN deprecated source-map-resolve@0.5.2: See deprecated notice.

added 726 packages, and audited 727 packages in 4s

63 packages are looking for funding run npm fund for details

17 vulnerabilities (1 moderate, 8 high, 8 critical)

To address issues that do not require attention, run: npm audit fix

To address all issues (including breaking changes), run: npm audit fix --force

Run npm audit for details.

问题原因与解决方法 #

核心原因 #

Monaco编辑器会在用户输入时自动触发补全请求，即使你没主动调用autoSuggest方法。有问题的实现中，parseAndGetSyntaxErrors或后续的数组处理逻辑可能抛出未捕获异常，导致整个语言服务崩溃，进而影响语法着色、格式化等其他依赖语言服务的功能。

具体修复步骤 #

1. 添加异常捕获：在autoSuggest中包裹try-catch，避免异常扩散影响其他功能：

autoSuggest(code: string, line: number, charPosInLine: number): monaco.languages.CompletionList {
    try {
        const syntaxErrors: ILanguageError[] = parseAndGetSyntaxErrors(code);
        let completeonItems: Array<monaco.languages.CompletionItem> = syntaxErrors
            .filter(err => err.startLineNumber === line && err.startColumn === charPosInLine)
            .map(e => {
                // 校验字段合法性，避免访问undefined属性报错
                if (!e.startLineNumber || !e.startColumn || !e.endLineNumber || !e.endColumn) {
                    return null;
                }
                return {
                    label: e.message,
                    kind: monaco.languages.CompletionItemKind.Field,
                    insertText: e.message,
                    range: {
                        startLineNumber: e.startLineNumber,
                        startColumn: e.startColumn,
                        endLineNumber: e.endLineNumber,
                        endColumn: e.endColumn
                    }
                }
            })
            .filter(item => item !== null); // 过滤无效项

        return { suggestions: completeonItems };
    } catch (err) {
        console.error('AutoSuggest异常:', err);
        return { suggestions: [] };
    }
}

2. 检查解析器稳定性：确认parseAndGetSyntaxErrors方法不会因语法错误代码抛出异常，确保它始终返回合法的ILanguageError数组。
3. 升级依赖（可选）：执行npm audit fix --force更新有漏洞的依赖包，避免潜在的底层bug影响。

内容的提问来源于stack exchange，提问作者Vladimir Kozhaev