js-error-fixer

JavaScript Error Checker and Fixer

Trigger Mapping

User input trigger words	AI execution actions
"Check JS errors" / "Fix JS issues" / "JS syntax errors"	Execute according to [Check and Fix Mode]
"Check folder" / "Batch process JS" / "Fix all JS"	Execute according to [Batch Processing Mode]
"Check this file" / "Fix this JS"	Execute according to [Single File Mode]

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Execution Modes

Check and Fix Mode

Trigger: the user mentions checking or fixing JS errors

Step	Execution action	Specific command/operation
1	Check ESLint configuration	Check whether the project has ESLint and a configuration file installed
2	Install ESLint (if needed)	Run npm install --save-dev eslint globals to install dependencies
3	Configure ESLint (if needed)	Create eslint.config.js configuration file
4	Run ESLint check	Execute npx eslint <路径> to check JS files
5	Analyze errors	Classify and count errors: syntax errors, type errors, others
6	Create to-dos	Run TodoWrite to create a fix task list
7	Fix one by one	Fix files one by one by priority, using Read and SearchReplace
8	Verify fixes	Run ESLint again to confirm the errors have been fixed
9	Output report	List the fixed files and error types

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Batch Processing Mode

Trigger: the user mentions a folder or batch processing

Step	Execution action	Specific command/operation
1	Get directory path	Ask the user or get the target folder path from context
2	Find JS files	Run Glob to search for **/*.js files
3	Check ESLint	Run ESLint to check all JS file errors
4	Create to-dos	Run TodoWrite to list all files to be fixed
5	Batch fix	Loop through each file with errors
6	Verify results	Run ESLint again and output a fix report

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Single File Mode

Trigger: the user specifies a certain JS file

Step	Execution action	Specific command/operation
1	Get file path	Get the file path from user input or context
2	Read file	Run Read to read the file contents
3	Check ESLint	Run ESLint to check the file for errors
4	Analyze the problem	Locate the specific error position and type
5	Perform the fix	Use SearchReplace or rewrite the file to fix
6	Verify the fix	Run ESLint again to confirm the fix is complete

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ESLint Configuration Guide

Install ESLint

Step	Action	Command
1	Enter the project directory	cd <项目路径>
2	Install ESLint	npm install --save-dev eslint
3	Install the globals package	npm install --save-dev globals

Create the ESLint configuration file

Create the eslint.config.js configuration file (flat config format):

import globals from "globals";

export default [
  {
    languageOptions: {
      ecmaVersion: "latest",
      sourceType: "module",
      globals: {
        ...globals.node,
        ...globals.es2022
      }
    },
    rules: {
      "no-undef": "error",
      "no-unused-vars": "warn",
      "semi": [
        "error",
        "always"
      ],
      "quotes": [
        "error",
        "double"
      ]
    }
  }
];

Run ESLint check

Check scope	Command
Check a single file	npx eslint <文件路径>
Check the entire directory	npx eslint <目录路径>
Check all JS in the current directory	npx eslint .

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Common error fix strategies

Error type	Error symptom	Fix method
HTML entity encoding	Special characters are encoded	Replace the encoded characters with the actual characters
Missing closing parenthesis )	Diagnostic message "expected ')'"	Find the corresponding opening parenthesis position and add it at the correct position )
Missing semicolon ;	Diagnostic message "expected ';'"	Add it at the end of the statement ;
Quote mismatch	String quotes are not closed	Check the string and complete the closing quote
Brace mismatch	{ The counts of and do not match } The counts do not match	Find the missing { or }
Undefined variable	An undeclared variable is used	Check the variable scope, add a declaration, or correct the spelling

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Error handling

Error scenario	Error symptom	Handling method
No JS files	Glob search result is empty	Prompt the user that no JS files were found and ask whether to adjust the path
No ESLint errors	ESLint returns empty	Output "No errors found" and end the task
File cannot be read	Read returns an error	Skip the file, record it in the report, and continue processing other files
Errors remain after fixing	ESLint still reports problems after fixing	Mark as "needs manual inspection" and continue processing other files
ESLint is not installed	npx eslint failed	Install ESLint and the globals package first

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Core principles checklist

Principle	Check standard	Pass?
⭐⭐⭐ Human-centered	Users only need to speak natural language, and the AI automatically performs checks and fixes	✅
⭐⭐⭐ AI-first	Use imperative instructions, and display decision logic in tables	✅
⭐⭐⭐ Ready to use out of the box	There is a trigger mapping table, mapping user input → AI actions one-to-one	✅
Progressive disclosure	Core content is brief	✅
Error handling	Includes a table of common error scenarios and handling methods	✅