# Eslint Detector

> Detects ESLint configuration and available commands in a repository. Returns structured JSON output designed for consumption by the quality-gates-linter agent. Checks for ESLint config files, extracts lint commands from package.json, Makefile, and CLAUDE.md, and provides command sources for the agent to read directly. Use when this capability is needed.

- Skill: `tomevault-io/eslint-detector` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/eslint-detector`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/eslint-detector/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/eslint-detector

---


## Purpose

Detect ESLint presence and available commands in a repository, returning structured JSON data specifically formatted for the quality-gates-linter agent to consume.

## When to Use

Invoke this skill during Phase 0 (Environment Detection) of the quality-gates-linter agent workflow to:
- Verify ESLint is configured in the repository
- Identify available ESLint commands (check and fix)
- Locate command sources for the agent to read directly

This skill should NOT be invoked for general code review or linting tasks - only for environment detection.

## Detection Process

### Step 1: Check for ESLint Configuration

Search for ESLint configuration files using Glob tool:
- `.eslintrc.js`
- `.eslintrc.json`
- `.eslintrc.yml`
- `.eslintrc.yaml`
- `eslint.config.js` (flat config)
- `package.json` (check for `eslintConfig` field)

If NO configuration files found:
- Set `eslintDetected: false`
- Return early with minimal JSON structure

If configuration files found:
- Set `eslintDetected: true`
- Record all found config files with paths and types
- Proceed to Step 2

### Step 2: Detect ESLint Commands

Search for ESLint commands in priority order:

#### 2a. Check CLAUDE.md (Highest Priority)

If `CLAUDE.md` exists:
- Read the file
- Search for sections: "Linting", "Development Commands", "Code Quality", "Common Commands"
- Look for command patterns:
  - Check commands: `eslint`, `lint`, `make lint`, `npm run lint`
  - Fix commands: `eslint --fix`, `lint-fix`, `make lint-fix`, `npm run lint:fix`
- Extract exact commands mentioned
- Record CLAUDE.md as source if commands found

#### 2b. Check package.json Scripts

Read `package.json` and examine the `scripts` section:

**Lint check commands** (look for these script names):
- `"lint"`
- `"eslint"`
- `"lint:check"`
- Extract as: `npm run <script-name>`

**Lint fix commands** (look for these script names):
- `"lint:fix"`
- `"lint-fix"`
- `"fix"`
- `"eslint:fix"`
- Extract as: `npm run <script-name>`

Record package.json as source if commands found.

#### 2c. Check Makefile

If `Makefile` exists:
- Read the file
- Search for targets containing `eslint` or `lint`
- Common target patterns:
  - Check: `lint`, `eslint`, `check`
  - Fix: `lint-fix`, `fix`, `format`
- Extract as: `make <target-name>`
- Record Makefile as source if commands found

#### 2d. Fallback Commands

If no commands found in any source:
- Use fallback commands:
  - Check: `npx eslint .`
  - Fix: `npx eslint --fix .`
- Record source as: `"fallback"`

### Step 3: Build JSON Response

Construct JSON object with this exact structure:

```json
{
  "eslintDetected": true,
  "configFiles": [
    {
      "path": ".eslintrc.json",
      "type": "eslintrc"
    },
    {
      "path": "package.json",
      "type": "package-config"
    }
  ],
  "commands": {
    "check": {
      "command": "npm run lint",
      "source": "package.json"
    },
    "fix": {
      "command": "npm run lint:fix",
      "source": "package.json"
    }
  },
  "commandSources": [
    "package.json"
  ]
}
```

**Field Specifications:**

- `eslintDetected` (boolean): `true` if config found, `false` otherwise
- `configFiles` (array): List of all ESLint config files found
  - `path` (string): Relative path to config file
  - `type` (string): Config type (`"eslintrc"`, `"eslint-config-js"`, `"package-config"`)
- `commands` (object): Contains check and fix commands
  - `check` (object): Lint check command
    - `command` (string): Exact command to run
    - `source` (string): Where command was found
  - `fix` (object): Lint fix command
    - `command` (string): Exact command to run
    - `source` (string): Where command was found
- `commandSources` (array): Ordered list of sources where commands were found

### Step 4: Return JSON

Output the JSON structure in a code block with clear formatting:

````markdown
## ESLint Detection Results

```json
{
  "eslintDetected": true,
  "configFiles": [...],
  "commands": {...},
  "commandSources": [...]
}
```

**Summary:**
- ESLint detected: Yes/No
- Config files: <count>
- Commands source: <primary source>
````

## Priority Rules

1. **Command Priority**: CLAUDE.md > package.json > Makefile > fallback
2. **Use First Match**: For each command type (check/fix), use the first match found
3. **Source Transparency**: Always record where commands were found
4. **Config Completeness**: List ALL config files found, not just the first one

## Edge Cases

**Multiple config files found:**
- List all in `configFiles` array
- No impact on command detection

**Command found in multiple sources:**
- Use highest priority source (CLAUDE.md wins)
- Record only the used source in `commandSources`

**Only check OR only fix command found:**
- Return the found command
- For missing command, use fallback for that specific type

**No ESLint config found:**
```json
{
  "eslintDetected": false,
  "configFiles": [],
  "commands": {},
  "commandSources": []
}
```

**ESLint config found but no commands:**
```json
{
  "eslintDetected": true,
  "configFiles": [{...}],
  "commands": {
    "check": {
      "command": "npx eslint .",
      "source": "fallback"
    },
    "fix": {
      "command": "npx eslint --fix .",
      "source": "fallback"
    }
  },
  "commandSources": ["fallback"]
}
```

## Integration with quality-gates-linter

The quality-gates-linter agent will:
1. Invoke this skill during Phase 0
2. Parse the returned JSON structure
3. Use `eslintDetected` to decide whether to proceed or exit
4. Use `commands.check.command` for verification runs
5. Use `commands.fix.command` for auto-fix attempts
6. Read files listed in `commandSources` if needed for additional context

The JSON structure is designed to provide everything the linter agent needs without requiring additional file reads for command detection.

---
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<!-- tomevault:4.0:skill_md:2026-04-11 -->