Custom Workflows

Programmatic API

Basic Usage

import { diagnose } from "react-doctor/api";

const result = await diagnose("./path/to/your/react-project");

console.log(result.score); // { score: 82, label: "Good" } or null
console.log(result.diagnostics); // Array of Diagnostic objects
console.log(result.project); // Detected framework, React version, etc.

With Options

import { diagnose } from "react-doctor/api";

const result = await diagnose(".", {
  lint: true, // run lint checks (default: true)
  deadCode: true, // run dead code detection (default: true)
});

// Filter by severity
const errors = result.diagnostics.filter((d) => d.severity === "error");
const warnings = result.diagnostics.filter((d) => d.severity === "warning");

console.log(`Errors: ${errors.length}, Warnings: ${warnings.length}`);

Diagnostic Structure

Each diagnostic has this shape:

interface Diagnostic {
  filePath: string;
  plugin: string;
  rule: string;
  severity: "error" | "warning";
  message: string;
  help: string;
  line: number;
  column: number;
  category: string;
}

Custom Scripts

Score Tracking Script

Track health score over time:

track-score.ts

import { diagnose } from "react-doctor/api";
import { writeFileSync, readFileSync, existsSync } from "fs";

const HISTORY_FILE = "react-doctor-history.json";

interface ScoreEntry {
  date: string;
  score: number;
  errors: number;
  warnings: number;
}

const loadHistory = (): ScoreEntry[] => {
  if (!existsSync(HISTORY_FILE)) return [];
  return JSON.parse(readFileSync(HISTORY_FILE, "utf-8"));
};

const saveHistory = (history: ScoreEntry[]) => {
  writeFileSync(HISTORY_FILE, JSON.stringify(history, null, 2));
};

const main = async () => {
  const result = await diagnose(".");
  
  const entry: ScoreEntry = {
    date: new Date().toISOString(),
    score: result.score?.score ?? 0,
    errors: result.diagnostics.filter((d) => d.severity === "error").length,
    warnings: result.diagnostics.filter((d) => d.severity === "warning").length,
  };

  const history = loadHistory();
  history.push(entry);
  saveHistory(history);

  console.log(`Score: ${entry.score}`);
  console.log(`Errors: ${entry.errors}, Warnings: ${entry.warnings}`);
  
  if (history.length > 1) {
    const previous = history[history.length - 2];
    const diff = entry.score - previous.score;
    console.log(`Change: ${diff > 0 ? "+" : ""}${diff}`);
  }
};

main();

Run daily in CI and commit the history file.

Generate Report

Create a formatted markdown report:

generate-report.ts

import { diagnose } from "react-doctor/api";
import { writeFileSync } from "fs";

const main = async () => {
  const result = await diagnose(".");

  const errors = result.diagnostics.filter((d) => d.severity === "error");
  const warnings = result.diagnostics.filter((d) => d.severity === "warning");

  const report = `# React Doctor Report

**Score:** ${result.score?.score ?? "N/A"} / 100 (${result.score?.label ?? "Unknown"})

**Framework:** ${result.project?.framework ?? "Unknown"}
**React Version:** ${result.project?.reactVersion ?? "Unknown"}

## Summary

- Errors: ${errors.length}
- Warnings: ${warnings.length}
- Total Issues: ${result.diagnostics.length}

## Issues by Category

${generateCategoryBreakdown(result.diagnostics)}

## Top Issues

${generateTopIssues(errors, warnings)}
`;

  writeFileSync("react-doctor-report.md", report);
  console.log("Report generated: react-doctor-report.md");
};

const generateCategoryBreakdown = (diagnostics: any[]) => {
  const categories = new Map<string, number>();
  
  diagnostics.forEach((d) => {
    categories.set(d.category, (categories.get(d.category) ?? 0) + 1);
  });

  return Array.from(categories.entries())
    .sort((a, b) => b[1] - a[1])
    .map(([category, count]) => `- **${category}:** ${count}`)
    .join("\n");
};

const generateTopIssues = (errors: any[], warnings: any[]) => {
  const topIssues = [...errors.slice(0, 5), ...warnings.slice(0, 5)];
  
  if (topIssues.length === 0) return "No issues found!";

  return topIssues
    .map((d) => `### ${d.severity.toUpperCase()}: ${d.rule}\n\n${d.message}\n\n**File:** ${d.filePath}:${d.line}:${d.column}\n\n${d.help}`)
    .join("\n\n---\n\n");
};

main();

Combining with Other Tools

With ESLint

Run React Doctor after ESLint:

package.json

{
  "scripts": {
    "lint": "eslint . && react-doctor . --fail-on error",
    "lint:fix": "eslint . --fix && react-doctor . --verbose"
  }
}

With Prettier

package.json

{
  "scripts": {
    "format": "prettier --write . && react-doctor . --score",
    "check": "prettier --check . && react-doctor . --fail-on error"
  }
}

With TypeScript

Run in sequence:

package.json

{
  "scripts": {
    "typecheck": "tsc --noEmit",
    "validate": "npm run typecheck && react-doctor . --fail-on error"
  }
}

With Jest

Run after tests:

package.json

{
  "scripts": {
    "test": "jest",
    "test:full": "jest && react-doctor . --verbose"
  }
}

Fail-On Levels

Fail on Errors Only

npx -y react-doctor@latest . --fail-on error

Exit code 1 if any error-level diagnostics are found.

Fail on Warnings

npx -y react-doctor@latest . --fail-on warning

Exit code 1 if any diagnostics (errors or warnings) are found.

Never Fail

npx -y react-doctor@latest . --fail-on none

Always exit with code 0 (report only mode).

In Configuration

react-doctor.config.json

{
  "failOn": "warning"
}

CLI flag overrides config value:

# Config says "warning", but CLI overrides to "error"
npx -y react-doctor@latest . --fail-on error

Advanced Filtering

Filter by Category

filter-by-category.ts

import { diagnose } from "react-doctor/api";

const result = await diagnose(".");

// Get only performance issues
const performanceIssues = result.diagnostics.filter(
  (d) => d.category === "performance"
);

console.log(`Performance issues: ${performanceIssues.length}`);

performanceIssues.forEach((issue) => {
  console.log(`${issue.filePath}:${issue.line} - ${issue.message}`);
});

Filter by Plugin

filter-by-plugin.ts

import { diagnose } from "react-doctor/api";

const result = await diagnose(".");

// Get only React-specific issues
const reactIssues = result.diagnostics.filter((d) => d.plugin === "react");

// Get only dead code issues
const deadCodeIssues = result.diagnostics.filter((d) => d.plugin === "knip");

console.log(`React issues: ${reactIssues.length}`);
console.log(`Dead code issues: ${deadCodeIssues.length}`);

Filter by File Pattern

filter-by-file.ts

import { diagnose } from "react-doctor/api";

const result = await diagnose(".");

// Get issues in test files
const testIssues = result.diagnostics.filter(
  (d) => d.filePath.includes(".test.") || d.filePath.includes(".spec.")
);

// Get issues in components
const componentIssues = result.diagnostics.filter(
  (d) => d.filePath.includes("/components/")
);

console.log(`Test file issues: ${testIssues.length}`);
console.log(`Component issues: ${componentIssues.length}`);

Score Thresholds

Enforce Minimum Score

enforce-score.ts

import { diagnose } from "react-doctor/api";

const MIN_SCORE = 75;

const result = await diagnose(".");
const score = result.score?.score ?? 0;

if (score < MIN_SCORE) {
  console.error(`Score ${score} is below minimum ${MIN_SCORE}`);
  process.exit(1);
}

console.log(`Score ${score} meets minimum threshold`);

Prevent Score Regression

prevent-regression.ts

import { diagnose } from "react-doctor/api";
import { readFileSync, existsSync } from "fs";

const BASELINE_FILE = "react-doctor-baseline.json";

const result = await diagnose(".");
const currentScore = result.score?.score ?? 0;

if (existsSync(BASELINE_FILE)) {
  const baseline = JSON.parse(readFileSync(BASELINE_FILE, "utf-8"));
  const baselineScore = baseline.score ?? 0;

  if (currentScore < baselineScore) {
    console.error(
      `Score regression detected: ${currentScore} < ${baselineScore}`
    );
    process.exit(1);
  }

  console.log(`Score improved: ${baselineScore} → ${currentScore}`);
} else {
  console.log("No baseline found. Current score:", currentScore);
}

Monorepo Workflows

Parallel Project Scans

scan-all-projects.ts

import { diagnose } from "react-doctor/api";
import path from "path";

const PROJECTS = ["apps/web", "apps/admin", "apps/mobile"];

const scanAll = async () => {
  const results = await Promise.all(
    PROJECTS.map(async (project) => {
      const result = await diagnose(path.join(process.cwd(), project));
      return { project, result };
    })
  );

  results.forEach(({ project, result }) => {
    console.log(`\n${project}:`);
    console.log(`  Score: ${result.score?.score ?? "N/A"}`);
    console.log(`  Issues: ${result.diagnostics.length}`);
  });

  const totalIssues = results.reduce(
    (sum, { result }) => sum + result.diagnostics.length,
    0
  );
  console.log(`\nTotal issues across all projects: ${totalIssues}`);
};

scanAll();

Conditional Project Scanning

Scan only projects with changes:

scan-changed-projects.sh

#!/bin/bash

# Get changed files
CHANGED_FILES=$(git diff --name-only main...HEAD)

# Scan web if it changed
if echo "$CHANGED_FILES" | grep -q "^apps/web/"; then
  echo "Scanning web..."
  npx -y react-doctor@latest apps/web --fail-on error
fi

# Scan admin if it changed
if echo "$CHANGED_FILES" | grep -q "^apps/admin/"; then
  echo "Scanning admin..."
  npx -y react-doctor@latest apps/admin --fail-on error
fi

Notification Integrations

Slack Notification

notify-slack.ts

import { diagnose } from "react-doctor/api";

const WEBHOOK_URL = process.env.SLACK_WEBHOOK_URL!;

const result = await diagnose(".");
const score = result.score?.score ?? 0;
const errors = result.diagnostics.filter((d) => d.severity === "error").length;
const warnings = result.diagnostics.filter((d) => d.severity === "warning").length;

const message = {
  text: `React Doctor Scan Complete`,
  blocks: [
    {
      type: "section",
      text: {
        type: "mrkdwn",
        text: `*React Doctor Scan*\n\nScore: *${score}*/100\nErrors: ${errors}\nWarnings: ${warnings}`,
      },
    },
  ],
};

await fetch(WEBHOOK_URL, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(message),
});

Discord Notification

notify-discord.ts

import { diagnose } from "react-doctor/api";

const WEBHOOK_URL = process.env.DISCORD_WEBHOOK_URL!;

const result = await diagnose(".");
const score = result.score?.score ?? 0;

const embed = {
  embeds: [
    {
      title: "React Doctor Scan Complete",
      color: score >= 75 ? 0x00ff00 : score >= 50 ? 0xffff00 : 0xff0000,
      fields: [
        { name: "Score", value: `${score}/100`, inline: true },
        { name: "Label", value: result.score?.label ?? "Unknown", inline: true },
        { name: "Total Issues", value: String(result.diagnostics.length), inline: true },
      ],
    },
  ],
};

await fetch(WEBHOOK_URL, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(embed),
});

Tips

Use --fail-on error in development and --fail-on warning in production branches

Combine React Doctor with other tools in a single validate script for comprehensive checks

Track your score over time to visualize codebase health improvements

Get Started

Usage

Rules Reference

Guides

Examples

Programmatic API

Basic Usage

With Options

Diagnostic Structure

Custom Scripts

Score Tracking Script

Generate Report

Combining with Other Tools

With ESLint

With Prettier

With TypeScript

With Jest

Fail-On Levels

Fail on Errors Only

Fail on Warnings

Never Fail

In Configuration

Advanced Filtering

Filter by Category

Filter by Plugin

Filter by File Pattern

Score Thresholds

Enforce Minimum Score

Prevent Score Regression

Monorepo Workflows

Parallel Project Scans

Conditional Project Scanning

Notification Integrations

Slack Notification

Discord Notification

Tips

Build docs developers (and LLMs) love

Get Started

Usage

Rules Reference

Guides

Examples

​Programmatic API

​Basic Usage

​With Options

​Diagnostic Structure

​Custom Scripts

​Score Tracking Script

​Generate Report

​Combining with Other Tools

​With ESLint

​With Prettier

​With TypeScript

​With Jest

​Fail-On Levels

​Fail on Errors Only

​Fail on Warnings

​Never Fail

​In Configuration

​Advanced Filtering

​Filter by Category

​Filter by Plugin

​Filter by File Pattern

​Score Thresholds

​Enforce Minimum Score

​Prevent Score Regression

​Monorepo Workflows

​Parallel Project Scans

​Conditional Project Scanning

​Notification Integrations

​Slack Notification

​Discord Notification

​Tips

Build docs developers (and LLMs) love

Programmatic API

Basic Usage

With Options

Diagnostic Structure

Custom Scripts

Score Tracking Script

Generate Report

Combining with Other Tools

With ESLint

With Prettier

With TypeScript

With Jest

Fail-On Levels

Fail on Errors Only

Fail on Warnings

Never Fail

In Configuration

Advanced Filtering

Filter by Category

Filter by Plugin

Filter by File Pattern

Score Thresholds

Enforce Minimum Score

Prevent Score Regression

Monorepo Workflows

Parallel Project Scans

Conditional Project Scanning

Notification Integrations

Slack Notification

Discord Notification

Tips