ESLint没有输出

Question

我正在尝试使用该教程中的ESLint：https://davidwalsh.name/eslint。我已经复制了示例文件。当我在目录中运行eslint uploader.js时，什么也没有发生——换行后提示符返回。没有任何输出。

我已经在同一目录下的JSON文件上运行它，并使用Grunt任务在整个项目的JS文件上运行它。这些会返回一些错误，但跟我的预期相差甚远。

当我在命令行上运行eslint时，它表现如预期——返回参数和选项文档。我尝试重新启动实例、重新安装ESLint，甚至有意将错误引入到uploader.js中，但什么也没发生，更不用说教程中显示的输出了。能有人提供帮助吗？

- Ben

---

你期望得到什么输出呢？ eslint 只是一个检查工具。 - E net4

教程非常具体，可以预期哪些错误-它们提供了一个示例文件及其输出（在“实际示例”中从顶部开始的第一张图片）。 - Ben

Answer 1

从 ESLint 1.0.0 版本开始，默认关闭所有的代码检测规则。

该教程是在此版本之前编写的，因此可能会出现一些错误而没有配置文件。官方网站提供了一个 迁移指南。在您的情况下，您可能希望在整个教程中使用 "eslint:recommended" 扩展您的 ".eslintrc" 文件（或仅手动包含预期规则）。根据指南，以下内容是最接近旧版本的：

{
    "extends": "eslint:recommended",
    "rules": {
        "no-alert": 2,
        "no-array-constructor": 2,
        "no-caller": 2,
        "no-catch-shadow": 2,
        "no-empty-label": 2,
        "no-eval": 2,
        "no-extend-native": 2,
        "no-extra-bind": 2,
        "no-implied-eval": 2,
        "no-iterator": 2,
        "no-label-var": 2,
        "no-labels": 2,
        "no-lone-blocks": 2,
        "no-loop-func": 2,
        "no-multi-spaces": 2,
        "no-multi-str": 2,
        "no-native-reassign": 2,
        "no-new": 2,
        "no-new-func": 2,
        "no-new-object": 2,
        "no-new-wrappers": 2,
        "no-octal-escape": 2,
        "no-process-exit": 2,
        "no-proto": 2,
        "no-return-assign": 2,
        "no-script-url": 2,
        "no-sequences": 2,
        "no-shadow": 2,
        "no-shadow-restricted-names": 2,
        "no-spaced-func": 2,
        "no-trailing-spaces": 2,
        "no-undef-init": 2,
        "no-underscore-dangle": 2,
        "no-unused-expressions": 2,
        "no-use-before-define": 2,
        "no-with": 2,
        "camelcase": 2,
        "comma-spacing": 2,
        "consistent-return": 2,
        "curly": [2, "all"],
        "dot-notation": [2, { "allowKeywords": true }],
        "eol-last": 2,
        "no-extra-parens": [2, "functions"],
        "eqeqeq": 2,
        "key-spacing": [2, { "beforeColon": false, "afterColon": true }],
        "new-cap": 2,
        "new-parens": 2,
        "quotes": [2, "double"],
        "semi": 2,
        "semi-spacing": [2, {"before": false, "after": true}],
        "space-infix-ops": 2,
        "space-return-throw-case": 2,
        "space-unary-ops": [2, { "words": true, "nonwords": false }],
        "strict": [2, "function"],
        "yoda": [2, "never"]
    }
}

---

自从 版本 3.0.0 起，ESLint 将拒绝在没有配置文件的情况下工作，并打印出错误信息。这将有望防止人们遇到此问题。

- E_net4

---

是的！ 小错误是最糟糕的。谢谢！很惊讶，因为这个教程甚至还不到一年... - Ben

很高兴能帮助到你。老实说，我更喜欢新的行为方式，它不那么狂热。根据迁移指南，我已添加了完整的.eslintrc文件（可以看到，它有许多规则）。 - E net4

Answer 2

我也遇到了同样的问题（顺便说一下，是在2023年）。我安装了eslint，但当我输入npx eslint app.js时，它返回的结果是空的，只有一个新的空行。 所以，对我来说解决方案是：

1. I checked globally installed eslint npm list -g

2. Eslint was installed globally, and I didn't want that, so I deleted it npm uninstall -g eslint

3. Then I checked that package.json was on place (If you don't have package.json, then create it npm init and hit enter several times)

4. I reinstalled eslint npm init eslint@/config

5. And the most important part: in .eslintrc.json (which will be created after installing eslint) you have to set rules (I took this solution from an answer E_net4). For example:

    {
        "extends": "eslint:recommended",
        "rules": {
            "no-alert": 2,
            "no-array-constructor": 2,
            "no-caller": 2,
            "no-catch-shadow": 2,
            "no-empty-label": 2,
            "no-eval": 2,
            "no-extend-native": 2,
            "no-extra-bind": 2,
            "no-implied-eval": 2,
            "no-iterator": 2,
            "no-label-var": 2,
            "no-labels": 2,
            "no-lone-blocks": 2,
            "no-loop-func": 2,
            "no-multi-spaces": 2,
            "no-multi-str": 2,
            "no-native-reassign": 2,
            "no-new": 2,
            "no-new-func": 2,
            "no-new-object": 2,
            "no-new-wrappers": 2,
            "no-octal-escape": 2,
            "no-process-exit": 2,
            "no-proto": 2,
            "no-return-assign": 2,
            "no-script-url": 2,
            "no-sequences": 2,
            "no-shadow": 2,
            "no-shadow-restricted-names": 2,
            "no-spaced-func": 2,
            "no-trailing-spaces": 2,
            "no-undef-init": 2,
            "no-underscore-dangle": 2,
            "no-unused-expressions": 2,
            "no-use-before-define": 2,
            "no-with": 2,
            "camelcase": 2,
            "comma-spacing": 2,
            "consistent-return": 2,
            "curly": [2, "all"],
            "dot-notation": [2, { "allowKeywords": true }],
            "eol-last": 2,
            "no-extra-parens": [2, "functions"],
            "eqeqeq": 2,
            "key-spacing": [2, { "beforeColon": false, "afterColon": true }],
            "new-cap": 2,
            "new-parens": 2,
            "quotes": [2, "double"],
            "semi": 2,
            "semi-spacing": [2, {"before": false, "after": true}],
            "space-infix-ops": 2,
            "space-return-throw-case": 2,
            "space-unary-ops": [2, { "words": true, "nonwords": false }],
            "strict": [2, "function"],
            "yoda": [2, "never"]
        }
    }
   

6. And npx eslint app.js returned a bunch of errors in my code (as it suppose to work). But I decided to change rules to some "standardized rules" and installed airbnb rules (instructions here https://www.npmjs.com/package/eslint-config-airbnb)

谢谢E_net4提供了解决办法。

- Niko