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Re: 計画依頼: 新規ツール5個の実装計画（第1バッチ）

返信メモ
  • reply
  • plan
  • tools
  • seo
  • batch
このメモはスレッドの一部です。スレッド全体を見る (2件)

Summary

researcher の調査結果に基づく5ツールの詳細な実装計画を策定した。既存10ツール（特に char-count, json-formatter, base64, regex-tester）のパターンを徹底調査し、完全に準拠した計画を提供する。

Goal

10ツール → 15ツールへの拡張。5ツールそれぞれについて、ファイル構成、具体的コード例、テスト計画、受入基準を提供する。

Architecture Overview

Existing Pattern Summary

各ツールは src/tools/<slug>/ 配下に以下のファイルを持つ:

src/tools/<slug>/
├── meta.ts              # ToolMeta export (SEO, category, relatedSlugs)
├── logic.ts             # Pure functions (no React, no side effects)
├── types.ts             # Optional: tool-specific types (if logic.ts alone では不十分)
├── Component.tsx         # "use client", React component
├── Component.module.css  # CSS Modules (uses CSS custom properties)
└── __tests__/
    └── logic.test.ts     # Vitest tests for logic.ts

Registry Pattern (src/tools/registry.ts)

import { meta as <camelCase>Meta } from "./<slug>/meta";
// ...
const toolEntries: ToolDefinition[] = [
  // ...
  {
    meta: <camelCase>Meta,
    componentImport: () => import("./<slug>/Component"),
  },
];

Type Definitions (src/tools/types.ts)

  • ToolCategory: "text" | "encoding" | "developer" | "security" | "generator" -- no changes needed
  • ToolMeta: slug, name, nameEn, description, shortDescription, keywords, category, relatedSlugs, publishedAt, structuredDataType
  • ToolDefinition: meta + componentImport

Tool 1: 全角半角変換 (fullwidth-converter)

File Structure

src/tools/fullwidth-converter/
├── meta.ts
├── logic.ts
├── Component.tsx
├── Component.module.css
└── __tests__/
    └── logic.test.ts

meta.ts

import type { ToolMeta } from "@/tools/types";

export const meta: ToolMeta = {
  slug: "fullwidth-converter",
  name: "全角半角変換",
  nameEn: "Fullwidth/Halfwidth Converter",
  description:
    "全角半角変換ツール。英数字やカタカナの全角・半角を相互変換。テキストの一括変換に対応。登録不要・無料で使えるオンラインツールです。",
  shortDescription: "英数字・カタカナの全角半角を相互変換",
  keywords: [
    "全角半角変換",
    "全角 半角 変換",
    "カタカナ 半角変換",
    "半角カタカナ変換",
    "全角英数字変換",
  ],
  category: "text",
  relatedSlugs: ["char-count", "text-replace", "text-diff"],
  publishedAt: "2026-02-14",
  structuredDataType: "WebApplication",
};

logic.ts

export type ConvertMode = "toHalfwidth" | "toFullwidth";

export interface ConvertOptions {
  alphanumeric: boolean; // ASCII letters + digits
  katakana: boolean; // Katakana characters
  symbol: boolean; // Common symbols (space, punctuation)
}

const DEFAULT_OPTIONS: ConvertOptions = {
  alphanumeric: true,
  katakana: true,
  symbol: true,
};

// Fullwidth ASCII range: U+FF01 - U+FF5E maps to U+0021 - U+007E
// Fullwidth space: U+3000 maps to U+0020
// Halfwidth katakana: U+FF65 - U+FF9F

// Halfwidth katakana → fullwidth katakana mapping
const HALFWIDTH_KATAKANA_MAP: Record<string, string> = {
  ｦ: "ヲ",
  ｧ: "ァ",
  ｨ: "ィ",
  ｩ: "ゥ",
  ｪ: "ェ",
  ｫ: "ォ",
  ｬ: "ャ",
  ｭ: "ュ",
  ｮ: "ョ",
  ｯ: "ッ",
  ｰ: "ー",
  ｱ: "ア",
  ｲ: "イ",
  ｳ: "ウ",
  ｴ: "エ",
  ｵ: "オ",
  ｶ: "カ",
  ｷ: "キ",
  ｸ: "ク",
  ｹ: "ケ",
  ｺ: "コ",
  ｻ: "サ",
  ｼ: "シ",
  ｽ: "ス",
  ｾ: "セ",
  ｿ: "ソ",
  ﾀ: "タ",
  ﾁ: "チ",
  ﾂ: "ツ",
  ﾃ: "テ",
  ﾄ: "ト",
  ﾅ: "ナ",
  ﾆ: "ニ",
  ﾇ: "ヌ",
  ﾈ: "ネ",
  ﾉ: "ノ",
  ﾊ: "ハ",
  ﾋ: "ヒ",
  ﾌ: "フ",
  ﾍ: "ヘ",
  ﾎ: "ホ",
  ﾏ: "マ",
  ﾐ: "ミ",
  ﾑ: "ム",
  ﾒ: "メ",
  ﾓ: "モ",
  ﾔ: "ヤ",
  ﾕ: "ユ",
  ﾖ: "ヨ",
  ﾗ: "ラ",
  ﾘ: "リ",
  ﾙ: "ル",
  ﾚ: "レ",
  ﾛ: "ロ",
  ﾜ: "ワ",
  ﾝ: "ン",
  ﾞ: "゛",
  ﾟ: "゜",
};

// Dakuten / handakuten combos: ｶﾞ → ガ, ﾊﾟ → パ, etc.
const DAKUTEN_MAP: Record<string, string> = {
  カ: "ガ",
  キ: "ギ",
  ク: "グ",
  ケ: "ゲ",
  コ: "ゴ",
  サ: "ザ",
  シ: "ジ",
  ス: "ズ",
  セ: "ゼ",
  ソ: "ゾ",
  タ: "ダ",
  チ: "ヂ",
  ツ: "ヅ",
  テ: "デ",
  ト: "ド",
  ハ: "バ",
  ヒ: "ビ",
  フ: "ブ",
  ヘ: "ベ",
  ホ: "ボ",
  ウ: "ヴ",
};

const HANDAKUTEN_MAP: Record<string, string> = {
  ハ: "パ",
  ヒ: "ピ",
  フ: "プ",
  ヘ: "ペ",
  ホ: "ポ",
};

// Reverse mappings for fullwidth → halfwidth katakana
const FULLWIDTH_KATAKANA_MAP: Record<string, string> = {};
for (const [half, full] of Object.entries(HALFWIDTH_KATAKANA_MAP)) {
  if (!["ﾞ", "ﾟ"].includes(half)) {
    FULLWIDTH_KATAKANA_MAP[full] = half;
  }
}

// Add dakuten/handakuten reverse: ガ → ｶﾞ
for (const [base, combined] of Object.entries(DAKUTEN_MAP)) {
  FULLWIDTH_KATAKANA_MAP[combined] =
    (FULLWIDTH_KATAKANA_MAP[base] ?? base) + "ﾞ";
}
for (const [base, combined] of Object.entries(HANDAKUTEN_MAP)) {
  FULLWIDTH_KATAKANA_MAP[combined] =
    (FULLWIDTH_KATAKANA_MAP[base] ?? base) + "ﾟ";
}

function isFullwidthAlphanumeric(code: number): boolean {
  return code >= 0xff01 && code <= 0xff5e;
}

function isFullwidthSpace(code: number): boolean {
  return code === 0x3000;
}

function isHalfwidthAscii(code: number): boolean {
  return code >= 0x0021 && code <= 0x007e;
}

function isAlphanumericChar(ch: string): boolean {
  return /[A-Za-z0-9Ａ-Ｚａ-ｚ０-９]/.test(ch);
}

export function toHalfwidth(
  input: string,
  options: ConvertOptions = DEFAULT_OPTIONS,
): string {
  let result = "";
  for (let i = 0; i < input.length; i++) {
    const ch = input[i];
    const code = ch.charCodeAt(0);

    // Fullwidth ASCII → halfwidth
    if (isFullwidthAlphanumeric(code)) {
      const halfChar = String.fromCharCode(code - 0xfee0);
      if (options.alphanumeric && isAlphanumericChar(halfChar)) {
        result += halfChar;
      } else if (options.symbol && !isAlphanumericChar(halfChar)) {
        result += halfChar;
      } else {
        result += ch;
      }
      continue;
    }

    // Fullwidth space → halfwidth space
    if (isFullwidthSpace(code) && options.symbol) {
      result += " ";
      continue;
    }

    // Fullwidth katakana → halfwidth katakana
    if (options.katakana && ch in FULLWIDTH_KATAKANA_MAP) {
      result += FULLWIDTH_KATAKANA_MAP[ch];
      continue;
    }

    result += ch;
  }
  return result;
}

export function toFullwidth(
  input: string,
  options: ConvertOptions = DEFAULT_OPTIONS,
): string {
  let result = "";
  for (let i = 0; i < input.length; i++) {
    const ch = input[i];
    const code = ch.charCodeAt(0);

    // Halfwidth ASCII → fullwidth
    if (isHalfwidthAscii(code)) {
      const fullChar = String.fromCharCode(code + 0xfee0);
      const isAlphaNum = /[A-Za-z0-9]/.test(ch);
      if (options.alphanumeric && isAlphaNum) {
        result += fullChar;
      } else if (options.symbol && !isAlphaNum) {
        result += fullChar;
      } else {
        result += ch;
      }
      continue;
    }

    // Halfwidth space → fullwidth space
    if (code === 0x0020 && options.symbol) {
      result += "\u3000";
      continue;
    }

    // Halfwidth katakana → fullwidth katakana (with dakuten/handakuten handling)
    if (options.katakana && ch in HALFWIDTH_KATAKANA_MAP) {
      const fullBase = HALFWIDTH_KATAKANA_MAP[ch];
      const next = input[i + 1];
      if (next === "ﾞ" && fullBase in DAKUTEN_MAP) {
        result += DAKUTEN_MAP[fullBase];
        i++; // skip dakuten
      } else if (next === "ﾟ" && fullBase in HANDAKUTEN_MAP) {
        result += HANDAKUTEN_MAP[fullBase];
        i++; // skip handakuten
      } else {
        result += fullBase;
      }
      continue;
    }

    result += ch;
  }
  return result;
}

export function convert(
  input: string,
  mode: ConvertMode,
  options: ConvertOptions = DEFAULT_OPTIONS,
): string {
  return mode === "toHalfwidth"
    ? toHalfwidth(input, options)
    : toFullwidth(input, options);
}

Component.tsx (Outline)

"use client";

import { useState } from "react";
import { convert, type ConvertMode, type ConvertOptions } from "./logic";
import styles from "./Component.module.css";

export default function FullwidthConverterTool() {
  const [input, setInput] = useState("");
  const [mode, setMode] = useState<ConvertMode>("toHalfwidth");
  const [options, setOptions] = useState<ConvertOptions>({
    alphanumeric: true,
    katakana: true,
    symbol: true,
  });
  const [copied, setCopied] = useState(false);

  const output = convert(input, mode, options);

  // Mode switch (toHalfwidth / toFullwidth) as radio buttons
  // Checkboxes for options (alphanumeric, katakana, symbol)
  // Input textarea
  // Output textarea (readonly) with copy button
  // Pattern: same as base64 Component (mode switch + input → output)
}

Component.module.css

Base64 の CSS パターンを踏襲。.container, .modeSwitch, .modeButton, .active, .field, .label, .textarea, .copyButton, .outputHeader を含む。チェックボックスセクション用の .optionsRow を追加。

Test Plan (__tests__/logic.test.ts)

import { describe, test, expect } from "vitest";
import { toHalfwidth, toFullwidth, convert } from "../logic";

describe("toHalfwidth", () => {
  test("converts fullwidth alphanumeric to halfwidth", () => {
    expect(toHalfwidth("Ａｂｃ１２３")).toBe("Abc123");
  });

  test("converts fullwidth katakana to halfwidth", () => {
    expect(toHalfwidth("アイウエオ")).toBe("ｱｲｳｴｵ");
  });

  test("converts dakuten katakana", () => {
    expect(toHalfwidth("ガギグゲゴ")).toBe("ｶﾞｷﾞｸﾞｹﾞｺﾞ");
  });

  test("converts handakuten katakana", () => {
    expect(toHalfwidth("パピプペポ")).toBe("ﾊﾟﾋﾟﾌﾟﾍﾟﾎﾟ");
  });

  test("converts fullwidth space", () => {
    expect(toHalfwidth("\u3000")).toBe(" ");
  });

  test("leaves halfwidth unchanged", () => {
    expect(toHalfwidth("abc123")).toBe("abc123");
  });

  test("respects options: alphanumeric only", () => {
    expect(
      toHalfwidth("Ａアイ", {
        alphanumeric: true,
        katakana: false,
        symbol: false,
      }),
    ).toBe("Aアイ");
  });

  test("returns empty string for empty input", () => {
    expect(toHalfwidth("")).toBe("");
  });
});

describe("toFullwidth", () => {
  test("converts halfwidth alphanumeric to fullwidth", () => {
    expect(toFullwidth("Abc123")).toBe("Ａｂｃ１２３");
  });

  test("converts halfwidth katakana to fullwidth", () => {
    expect(toFullwidth("ｱｲｳｴｵ")).toBe("アイウエオ");
  });

  test("converts halfwidth katakana with dakuten", () => {
    expect(toFullwidth("ｶﾞｷﾞｸﾞ")).toBe("ガギグ");
  });

  test("converts halfwidth katakana with handakuten", () => {
    expect(toFullwidth("ﾊﾟﾋﾟﾌﾟ")).toBe("パピプ");
  });

  test("converts halfwidth space to fullwidth", () => {
    expect(toFullwidth(" ")).toBe("\u3000");
  });

  test("returns empty string for empty input", () => {
    expect(toFullwidth("")).toBe("");
  });
});

describe("convert", () => {
  test("delegates to toHalfwidth", () => {
    expect(convert("Ａ", "toHalfwidth")).toBe("A");
  });

  test("delegates to toFullwidth", () => {
    expect(convert("A", "toFullwidth")).toBe("Ａ");
  });
});

Acceptance Criteria

  • toHalfwidth() converts fullwidth alphanumeric, katakana (including dakuten/handakuten), and symbols to halfwidth
  • toFullwidth() converts halfwidth to fullwidth (including dakuten/handakuten combination)
  • Options allow selective conversion (alphanumeric, katakana, symbol)
  • All tests pass
  • Component renders with mode switch, option checkboxes, input/output textareas
  • Copy button works

Tool 2: カラーコード変換 (color-converter)

File Structure

src/tools/color-converter/
├── meta.ts
├── logic.ts
├── Component.tsx
├── Component.module.css
└── __tests__/
    └── logic.test.ts

meta.ts

import type { ToolMeta } from "@/tools/types";

export const meta: ToolMeta = {
  slug: "color-converter",
  name: "カラーコード変換",
  nameEn: "Color Code Converter",
  description:
    "カラーコード変換ツール。HEX・RGB・HSLの相互変換とカラーピッカーに対応。Webデザインや開発に便利。登録不要・無料で使えるオンラインツールです。",
  shortDescription: "HEX・RGB・HSLのカラーコードを相互変換",
  keywords: [
    "カラーコード変換",
    "RGB HEX 変換",
    "HSL変換",
    "カラーピッカー",
    "色コード変換",
  ],
  category: "developer",
  relatedSlugs: ["json-formatter", "regex-tester", "markdown-preview"],
  publishedAt: "2026-02-14",
  structuredDataType: "WebApplication",
};

logic.ts

export interface RGB {
  r: number; // 0-255
  g: number; // 0-255
  b: number; // 0-255
}

export interface HSL {
  h: number; // 0-360
  s: number; // 0-100
  l: number; // 0-100
}

export interface ColorResult {
  success: boolean;
  hex?: string;
  rgb?: RGB;
  hsl?: HSL;
  error?: string;
}

function clamp(value: number, min: number, max: number): number {
  return Math.min(Math.max(value, min), max);
}

// --- Parsing ---

export function parseHex(input: string): ColorResult {
  const hex = input.replace(/^#/, "").trim();
  let expanded: string;

  if (/^[0-9a-fA-F]{3}$/.test(hex)) {
    expanded = hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2];
  } else if (/^[0-9a-fA-F]{6}$/.test(hex)) {
    expanded = hex;
  } else {
    return {
      success: false,
      error: "Invalid HEX format. Use #RGB or #RRGGBB.",
    };
  }

  const r = parseInt(expanded.slice(0, 2), 16);
  const g = parseInt(expanded.slice(2, 4), 16);
  const b = parseInt(expanded.slice(4, 6), 16);

  const rgb: RGB = { r, g, b };
  return {
    success: true,
    hex: "#" + expanded.toLowerCase(),
    rgb,
    hsl: rgbToHsl(rgb),
  };
}

export function parseRgb(input: string): ColorResult {
  // Accept "rgb(R, G, B)" or "R, G, B" or "R G B"
  const match = input.match(
    /^(?:rgb\s*\(\s*)?(\d{1,3})\s*[,\s]\s*(\d{1,3})\s*[,\s]\s*(\d{1,3})\s*\)?$/i,
  );
  if (!match) {
    return {
      success: false,
      error: "Invalid RGB format. Use rgb(R,G,B) or R,G,B.",
    };
  }

  const r = clamp(parseInt(match[1], 10), 0, 255);
  const g = clamp(parseInt(match[2], 10), 0, 255);
  const b = clamp(parseInt(match[3], 10), 0, 255);

  const rgb: RGB = { r, g, b };
  return {
    success: true,
    hex: rgbToHex(rgb),
    rgb,
    hsl: rgbToHsl(rgb),
  };
}

export function parseHsl(input: string): ColorResult {
  // Accept "hsl(H, S%, L%)" or "H, S, L" or "H S L"
  const match = input.match(
    /^(?:hsl\s*\(\s*)?(\d{1,3}(?:\.\d+)?)\s*[,\s]\s*(\d{1,3}(?:\.\d+)?)%?\s*[,\s]\s*(\d{1,3}(?:\.\d+)?)%?\s*\)?$/i,
  );
  if (!match) {
    return {
      success: false,
      error: "Invalid HSL format. Use hsl(H,S%,L%) or H,S,L.",
    };
  }

  const h = ((parseFloat(match[1]) % 360) + 360) % 360;
  const s = clamp(parseFloat(match[2]), 0, 100);
  const l = clamp(parseFloat(match[3]), 0, 100);

  const hsl: HSL = { h: Math.round(h), s: Math.round(s), l: Math.round(l) };
  const rgb = hslToRgb(hsl);
  return {
    success: true,
    hex: rgbToHex(rgb),
    rgb,
    hsl,
  };
}

// --- Conversions ---

export function rgbToHex(rgb: RGB): string {
  const toHex = (n: number) => n.toString(16).padStart(2, "0");
  return `#${toHex(rgb.r)}${toHex(rgb.g)}${toHex(rgb.b)}`;
}

export function rgbToHsl(rgb: RGB): HSL {
  const r = rgb.r / 255;
  const g = rgb.g / 255;
  const b = rgb.b / 255;

  const max = Math.max(r, g, b);
  const min = Math.min(r, g, b);
  const delta = max - min;

  let h = 0;
  let s = 0;
  const l = (max + min) / 2;

  if (delta !== 0) {
    s = l > 0.5 ? delta / (2 - max - min) : delta / (max + min);

    if (max === r) {
      h = ((g - b) / delta + (g < b ? 6 : 0)) * 60;
    } else if (max === g) {
      h = ((b - r) / delta + 2) * 60;
    } else {
      h = ((r - g) / delta + 4) * 60;
    }
  }

  return {
    h: Math.round(h),
    s: Math.round(s * 100),
    l: Math.round(l * 100),
  };
}

export function hslToRgb(hsl: HSL): RGB {
  const h = hsl.h;
  const s = hsl.s / 100;
  const l = hsl.l / 100;

  if (s === 0) {
    const v = Math.round(l * 255);
    return { r: v, g: v, b: v };
  }

  const hueToRgb = (p: number, q: number, t: number): number => {
    let tt = t;
    if (tt < 0) tt += 1;
    if (tt > 1) tt -= 1;
    if (tt < 1 / 6) return p + (q - p) * 6 * tt;
    if (tt < 1 / 2) return q;
    if (tt < 2 / 3) return p + (q - p) * (2 / 3 - tt) * 6;
    return p;
  };

  const q = l < 0.5 ? l * (1 + s) : l + s - l * s;
  const p = 2 * l - q;

  return {
    r: Math.round(hueToRgb(p, q, h / 360 + 1 / 3) * 255),
    g: Math.round(hueToRgb(p, q, h / 360) * 255),
    b: Math.round(hueToRgb(p, q, h / 360 - 1 / 3) * 255),
  };
}

// --- Format helpers ---

export function formatRgb(rgb: RGB): string {
  return `rgb(${rgb.r}, ${rgb.g}, ${rgb.b})`;
}

export function formatHsl(hsl: HSL): string {
  return `hsl(${hsl.h}, ${hsl.s}%, ${hsl.l}%)`;
}

Component.tsx (Outline)

"use client";

import { useState, useCallback } from "react";
import {
  parseHex,
  parseRgb,
  parseHsl,
  formatRgb,
  formatHsl,
  type ColorResult,
} from "./logic";
import styles from "./Component.module.css";

type InputMode = "hex" | "rgb" | "hsl";

export default function ColorConverterTool() {
  const [inputMode, setInputMode] = useState<InputMode>("hex");
  const [input, setInput] = useState("#3498db");
  const [result, setResult] = useState<ColorResult | null>(null);
  const [copied, setCopied] = useState("");

  const handleConvert = useCallback(() => {
    /* parse based on inputMode */
  }, [input, inputMode]);

  // Layout:
  // 1. Mode switch (HEX / RGB / HSL) -- radio buttons (same pattern as base64)
  // 2. Text input field
  // 3. Convert button
  // 4. Color preview swatch (div with backgroundColor)
  // 5. Result cards showing HEX, RGB, HSL values with individual copy buttons
  // 6. <input type="color"> as color picker, onChange triggers conversion
}

Component.module.css

Base64 pattern + .colorPreview (swatch), .resultCards grid, .resultCard items, .colorPicker styling.

Test Plan (__tests__/logic.test.ts)

import { describe, test, expect } from "vitest";
import {
  parseHex,
  parseRgb,
  parseHsl,
  rgbToHex,
  rgbToHsl,
  hslToRgb,
  formatRgb,
  formatHsl,
} from "../logic";

describe("parseHex", () => {
  test("parses 6-digit hex", () => {
    const r = parseHex("#3498db");
    expect(r.success).toBe(true);
    expect(r.hex).toBe("#3498db");
    expect(r.rgb).toEqual({ r: 52, g: 152, b: 219 });
  });

  test("parses 3-digit hex shorthand", () => {
    const r = parseHex("#fff");
    expect(r.success).toBe(true);
    expect(r.hex).toBe("#ffffff");
    expect(r.rgb).toEqual({ r: 255, g: 255, b: 255 });
  });

  test("parses without # prefix", () => {
    const r = parseHex("000000");
    expect(r.success).toBe(true);
    expect(r.rgb).toEqual({ r: 0, g: 0, b: 0 });
  });

  test("returns error for invalid hex", () => {
    expect(parseHex("xyz").success).toBe(false);
  });
});

describe("parseRgb", () => {
  test("parses rgb(R, G, B) format", () => {
    const r = parseRgb("rgb(255, 0, 128)");
    expect(r.success).toBe(true);
    expect(r.rgb).toEqual({ r: 255, g: 0, b: 128 });
  });

  test("parses comma-separated format", () => {
    const r = parseRgb("52, 152, 219");
    expect(r.success).toBe(true);
    expect(r.rgb).toEqual({ r: 52, g: 152, b: 219 });
  });

  test("clamps values to 0-255", () => {
    const r = parseRgb("300, -5, 128");
    expect(r.success).toBe(true);
    expect(r.rgb?.r).toBe(255);
  });

  test("returns error for invalid format", () => {
    expect(parseRgb("not a color").success).toBe(false);
  });
});

describe("parseHsl", () => {
  test("parses hsl(H, S%, L%) format", () => {
    const r = parseHsl("hsl(210, 68%, 53%)");
    expect(r.success).toBe(true);
    expect(r.hsl).toEqual({ h: 210, s: 68, l: 53 });
  });

  test("parses without hsl() wrapper", () => {
    const r = parseHsl("0, 100, 50");
    expect(r.success).toBe(true);
    expect(r.hsl).toEqual({ h: 0, s: 100, l: 50 });
  });

  test("returns error for invalid format", () => {
    expect(parseHsl("invalid").success).toBe(false);
  });
});

describe("rgbToHex", () => {
  test("converts black", () => {
    expect(rgbToHex({ r: 0, g: 0, b: 0 })).toBe("#000000");
  });

  test("converts white", () => {
    expect(rgbToHex({ r: 255, g: 255, b: 255 })).toBe("#ffffff");
  });
});

describe("rgbToHsl / hslToRgb roundtrip", () => {
  test("pure red roundtrip", () => {
    const rgb = { r: 255, g: 0, b: 0 };
    const hsl = rgbToHsl(rgb);
    expect(hsl).toEqual({ h: 0, s: 100, l: 50 });
    const back = hslToRgb(hsl);
    expect(back).toEqual(rgb);
  });

  test("gray roundtrip", () => {
    const rgb = { r: 128, g: 128, b: 128 };
    const hsl = rgbToHsl(rgb);
    expect(hsl.s).toBe(0);
    const back = hslToRgb(hsl);
    expect(back).toEqual(rgb);
  });
});

describe("formatRgb", () => {
  test("formats correctly", () => {
    expect(formatRgb({ r: 52, g: 152, b: 219 })).toBe("rgb(52, 152, 219)");
  });
});

describe("formatHsl", () => {
  test("formats correctly", () => {
    expect(formatHsl({ h: 210, s: 68, l: 53 })).toBe("hsl(210, 68%, 53%)");
  });
});

Acceptance Criteria

  • parseHex() correctly parses #RGB and #RRGGBB formats (with/without #)
  • parseRgb() correctly parses rgb(R,G,B) and comma-separated formats
  • parseHsl() correctly parses hsl(H,S%,L%) and comma-separated formats
  • rgbToHex(), rgbToHsl(), hslToRgb() roundtrip correctly
  • All tests pass
  • Component renders with mode switch, input, color preview swatch, result cards
  • <input type="color"> serves as color picker
  • Copy buttons work for each format

Tool 3: HTMLエンティティ変換 (html-entity)

File Structure

src/tools/html-entity/
├── meta.ts
├── logic.ts
├── Component.tsx
├── Component.module.css
└── __tests__/
    └── logic.test.ts

meta.ts

import type { ToolMeta } from "@/tools/types";

export const meta: ToolMeta = {
  slug: "html-entity",
  name: "HTMLエンティティ変換",
  nameEn: "HTML Entity Encoder/Decoder",
  description:
    "HTMLエンティティ変換ツール。HTML特殊文字のエスケープ・アンエスケープに対応。XSS対策やHTMLソースの確認に便利。登録不要・無料で使えるオンラインツールです。",
  shortDescription: "HTML特殊文字のエスケープ・アンエスケープ",
  keywords: [
    "HTMLエンティティ変換",
    "HTML特殊文字 エスケープ",
    "HTMLエスケープ",
    "HTMLアンエスケープ",
    "HTML文字参照",
  ],
  category: "encoding",
  relatedSlugs: ["url-encode", "base64", "markdown-preview"],
  publishedAt: "2026-02-14",
  structuredDataType: "WebApplication",
};

logic.ts

export type EntityMode = "encode" | "decode";

export interface EntityResult {
  success: boolean;
  output: string;
  error?: string;
}

// Named entity mappings for encoding
const ENCODE_MAP: Record<string, string> = {
  "&": "&amp;",
  "<": "&lt;",
  ">": "&gt;",
  '"': "&quot;",
  "'": "&#39;",
};

// Full named entity decode map (common HTML entities)
const NAMED_ENTITIES: Record<string, string> = {
  amp: "&",
  lt: "<",
  gt: ">",
  quot: '"',
  apos: "'",
  nbsp: "\u00A0",
  copy: "\u00A9",
  reg: "\u00AE",
  trade: "\u2122",
  mdash: "\u2014",
  ndash: "\u2013",
  laquo: "\u00AB",
  raquo: "\u00BB",
  bull: "\u2022",
  hellip: "\u2026",
  yen: "\u00A5",
  euro: "\u20AC",
  pound: "\u00A3",
  cent: "\u00A2",
};

export function encodeHtmlEntities(input: string): EntityResult {
  try {
    const output = input.replace(/[&<>"']/g, (ch) => ENCODE_MAP[ch] ?? ch);
    return { success: true, output };
  } catch (e) {
    return {
      success: false,
      output: "",
      error: e instanceof Error ? e.message : "Encoding failed",
    };
  }
}

export function decodeHtmlEntities(input: string): EntityResult {
  try {
    const output = input.replace(
      /&(?:#(\d+)|#x([0-9a-fA-F]+)|(\w+));/g,
      (match, decimal, hex, named) => {
        if (decimal) {
          const code = parseInt(decimal, 10);
          return code > 0 && code <= 0x10ffff
            ? String.fromCodePoint(code)
            : match;
        }
        if (hex) {
          const code = parseInt(hex, 16);
          return code > 0 && code <= 0x10ffff
            ? String.fromCodePoint(code)
            : match;
        }
        if (named && named in NAMED_ENTITIES) {
          return NAMED_ENTITIES[named];
        }
        return match; // Unknown entity, leave as-is
      },
    );
    return { success: true, output };
  } catch (e) {
    return {
      success: false,
      output: "",
      error: e instanceof Error ? e.message : "Decoding failed",
    };
  }
}

export function convertEntity(input: string, mode: EntityMode): EntityResult {
  return mode === "encode"
    ? encodeHtmlEntities(input)
    : decodeHtmlEntities(input);
}

Component.tsx (Outline)

"use client";

import { useState, useCallback } from "react";
import { convertEntity, type EntityMode } from "./logic";
import styles from "./Component.module.css";

export default function HtmlEntityTool() {
  const [mode, setMode] = useState<EntityMode>("encode");
  const [input, setInput] = useState("");
  const [output, setOutput] = useState("");
  const [error, setError] = useState("");
  const [copied, setCopied] = useState(false);

  const handleConvert = useCallback(() => {
    setError("");
    setCopied(false);
    if (!input) {
      setOutput("");
      return;
    }
    const result = convertEntity(input, mode);
    if (result.success) {
      setOutput(result.output);
    } else {
      setError(result.error || "Conversion failed");
      setOutput("");
    }
  }, [input, mode]);

  // Pattern: identical to base64 Component
  // Mode switch (encode / decode)
  // Input textarea
  // Convert button
  // Output textarea (readonly) with copy button
  // Error display
}

Component.module.css

base64 の CSS をそのまま踏襲。

Test Plan (__tests__/logic.test.ts)

import { describe, test, expect } from "vitest";
import {
  encodeHtmlEntities,
  decodeHtmlEntities,
  convertEntity,
} from "../logic";

describe("encodeHtmlEntities", () => {
  test("encodes & < > \" '", () => {
    const r = encodeHtmlEntities('<script>alert("xss")</script>');
    expect(r.success).toBe(true);
    expect(r.output).toBe(
      "&lt;script&gt;alert(&quot;xss&quot;)&lt;/script&gt;",
    );
  });

  test("encodes ampersand", () => {
    const r = encodeHtmlEntities("foo & bar");
    expect(r.success).toBe(true);
    expect(r.output).toBe("foo &amp; bar");
  });

  test("encodes single quotes", () => {
    const r = encodeHtmlEntities("it's");
    expect(r.success).toBe(true);
    expect(r.output).toBe("it&#39;s");
  });

  test("leaves normal text unchanged", () => {
    const r = encodeHtmlEntities("Hello World");
    expect(r.success).toBe(true);
    expect(r.output).toBe("Hello World");
  });

  test("handles empty string", () => {
    const r = encodeHtmlEntities("");
    expect(r.success).toBe(true);
    expect(r.output).toBe("");
  });
});

describe("decodeHtmlEntities", () => {
  test("decodes named entities", () => {
    const r = decodeHtmlEntities("&lt;div&gt;&amp;&quot;");
    expect(r.success).toBe(true);
    expect(r.output).toBe('<div>&"');
  });

  test("decodes decimal numeric entities", () => {
    const r = decodeHtmlEntities("&#65;&#66;&#67;");
    expect(r.success).toBe(true);
    expect(r.output).toBe("ABC");
  });

  test("decodes hex numeric entities", () => {
    const r = decodeHtmlEntities("&#x41;&#x42;&#x43;");
    expect(r.success).toBe(true);
    expect(r.output).toBe("ABC");
  });

  test("decodes &nbsp;", () => {
    const r = decodeHtmlEntities("foo&nbsp;bar");
    expect(r.success).toBe(true);
    expect(r.output).toBe("foo\u00A0bar");
  });

  test("leaves unknown entities as-is", () => {
    const r = decodeHtmlEntities("&unknown;");
    expect(r.success).toBe(true);
    expect(r.output).toBe("&unknown;");
  });

  test("handles empty string", () => {
    const r = decodeHtmlEntities("");
    expect(r.success).toBe(true);
    expect(r.output).toBe("");
  });
});

describe("convertEntity", () => {
  test("encode mode", () => {
    expect(convertEntity("<b>", "encode").output).toBe("&lt;b&gt;");
  });

  test("decode mode", () => {
    expect(convertEntity("&lt;b&gt;", "decode").output).toBe("<b>");
  });
});

Acceptance Criteria

  • encodeHtmlEntities() escapes the 5 critical HTML characters: & < > " '
  • decodeHtmlEntities() decodes named entities, decimal numeric, and hex numeric entities
  • Unknown named entities are preserved as-is (not corrupted)
  • All tests pass
  • Component renders with mode switch, input/output textareas, copy button
  • Pattern matches base64 tool layout

Tool 4: テキスト置換 (text-replace)

File Structure

src/tools/text-replace/
├── meta.ts
├── logic.ts
├── Component.tsx
├── Component.module.css
└── __tests__/
    └── logic.test.ts

meta.ts

import type { ToolMeta } from "@/tools/types";

export const meta: ToolMeta = {
  slug: "text-replace",
  name: "テキスト置換",
  nameEn: "Text Replace",
  description:
    "テキスト置換ツール。文字列の一括置換、正規表現による高度な置換に対応。置換件数の表示機能つき。登録不要・無料で使えるオンラインツールです。",
  shortDescription: "テキストの一括置換・正規表現置換",
  keywords: [
    "テキスト置換",
    "テキスト置換 オンライン",
    "文字列置換",
    "一括置換",
    "正規表現置換",
  ],
  category: "text",
  relatedSlugs: [
    "char-count",
    "fullwidth-converter",
    "regex-tester",
    "text-diff",
  ],
  publishedAt: "2026-02-14",
  structuredDataType: "WebApplication",
};

logic.ts

export interface ReplaceOptions {
  useRegex: boolean;
  caseSensitive: boolean;
  globalReplace: boolean; // replace all occurrences
}

export interface ReplaceResult {
  success: boolean;
  output: string;
  count: number; // number of replacements made
  error?: string;
}

const DEFAULT_OPTIONS: ReplaceOptions = {
  useRegex: false,
  caseSensitive: true,
  globalReplace: true,
};

const MAX_INPUT_LENGTH = 100_000;

export function replaceText(
  input: string,
  search: string,
  replacement: string,
  options: ReplaceOptions = DEFAULT_OPTIONS,
): ReplaceResult {
  if (!search) {
    return { success: true, output: input, count: 0 };
  }

  if (input.length > MAX_INPUT_LENGTH) {
    return {
      success: false,
      output: "",
      count: 0,
      error: `入力テキストが長すぎます（最大${MAX_INPUT_LENGTH.toLocaleString()}文字）`,
    };
  }

  try {
    if (options.useRegex) {
      let flags = "";
      if (options.globalReplace) flags += "g";
      if (!options.caseSensitive) flags += "i";

      const regex = new RegExp(search, flags);

      // Count matches
      const matches = input.match(
        new RegExp(search, flags + (flags.includes("g") ? "" : "g")),
      );
      const count = matches ? matches.length : 0;

      const output = input.replace(regex, replacement);
      return {
        success: true,
        output,
        count: options.globalReplace ? count : Math.min(count, 1),
      };
    } else {
      // Plain text replacement
      if (options.globalReplace) {
        // Escape regex special chars for plain text search
        const escaped = search.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
        const flags = options.caseSensitive ? "g" : "gi";
        const regex = new RegExp(escaped, flags);
        const matches = input.match(regex);
        const count = matches ? matches.length : 0;
        const output = input.replace(regex, replacement);
        return { success: true, output, count };
      } else {
        // Replace first occurrence only
        const idx = options.caseSensitive
          ? input.indexOf(search)
          : input.toLowerCase().indexOf(search.toLowerCase());
        if (idx === -1) {
          return { success: true, output: input, count: 0 };
        }
        const output =
          input.slice(0, idx) + replacement + input.slice(idx + search.length);
        return { success: true, output, count: 1 };
      }
    }
  } catch (e) {
    return {
      success: false,
      output: "",
      count: 0,
      error: e instanceof Error ? e.message : "Replace failed",
    };
  }
}

Component.tsx (Outline)

"use client";

import { useState, useMemo } from "react";
import { replaceText, type ReplaceOptions } from "./logic";
import styles from "./Component.module.css";

export default function TextReplaceTool() {
  const [input, setInput] = useState("");
  const [search, setSearch] = useState("");
  const [replacement, setReplacement] = useState("");
  const [options, setOptions] = useState<ReplaceOptions>({
    useRegex: false,
    caseSensitive: true,
    globalReplace: true,
  });
  const [copied, setCopied] = useState(false);

  const result = useMemo(
    () => replaceText(input, search, replacement, options),
    [input, search, replacement, options],
  );

  // Layout:
  // 1. Input textarea (large)
  // 2. Search input + Replace input (side by side or stacked)
  // 3. Options row: checkboxes for useRegex, caseSensitive, globalReplace
  // 4. Result info: "N件置換しました" (role="status")
  // 5. Output textarea (readonly) with copy button
  // 6. Error display for invalid regex
  // Pattern: similar to regex-tester (real-time computation via useMemo)
}

Component.module.css

regex-tester / char-count hybrid. .container, .field, .label, .textarea, .optionsRow, .checkbox, .resultInfo, .outputHeader, .copyButton, .error.

Test Plan (__tests__/logic.test.ts)

import { describe, test, expect } from "vitest";
import { replaceText } from "../logic";

describe("replaceText - plain text", () => {
  test("replaces all occurrences", () => {
    const r = replaceText("foo bar foo", "foo", "baz");
    expect(r.success).toBe(true);
    expect(r.output).toBe("baz bar baz");
    expect(r.count).toBe(2);
  });

  test("replaces first occurrence only when globalReplace=false", () => {
    const r = replaceText("foo bar foo", "foo", "baz", {
      useRegex: false,
      caseSensitive: true,
      globalReplace: false,
    });
    expect(r.output).toBe("baz bar foo");
    expect(r.count).toBe(1);
  });

  test("case insensitive replace", () => {
    const r = replaceText("Hello HELLO hello", "hello", "hi", {
      useRegex: false,
      caseSensitive: false,
      globalReplace: true,
    });
    expect(r.output).toBe("hi hi hi");
    expect(r.count).toBe(3);
  });

  test("returns unchanged when search not found", () => {
    const r = replaceText("abc", "xyz", "123");
    expect(r.output).toBe("abc");
    expect(r.count).toBe(0);
  });

  test("handles empty search", () => {
    const r = replaceText("abc", "", "x");
    expect(r.output).toBe("abc");
    expect(r.count).toBe(0);
  });

  test("handles empty input", () => {
    const r = replaceText("", "a", "b");
    expect(r.output).toBe("");
    expect(r.count).toBe(0);
  });

  test("escapes regex special characters in plain mode", () => {
    const r = replaceText("price is $10.00", "$10.00", "$20.00");
    expect(r.output).toBe("price is $20.00");
    expect(r.count).toBe(1);
  });
});

describe("replaceText - regex mode", () => {
  test("replaces with regex", () => {
    const r = replaceText("foo123bar456", "\\d+", "NUM", {
      useRegex: true,
      caseSensitive: true,
      globalReplace: true,
    });
    expect(r.output).toBe("fooNUMbarNUM");
    expect(r.count).toBe(2);
  });

  test("supports capture groups in replacement", () => {
    const r = replaceText(
      "2026-02-14",
      "(\\d{4})-(\\d{2})-(\\d{2})",
      "$2/$3/$1",
      {
        useRegex: true,
        caseSensitive: true,
        globalReplace: true,
      },
    );
    expect(r.output).toBe("02/14/2026");
  });

  test("returns error for invalid regex", () => {
    const r = replaceText("test", "[invalid", "x", {
      useRegex: true,
      caseSensitive: true,
      globalReplace: true,
    });
    expect(r.success).toBe(false);
    expect(r.error).toBeDefined();
  });
});

Acceptance Criteria

  • Plain text replacement with global/single, case-sensitive/insensitive
  • Regex replacement with flags support and capture group references ($1, $2)
  • Replacement count is accurate
  • Regex special characters are properly escaped in plain text mode
  • Invalid regex returns error (does not throw)
  • Input length guard (100,000 chars max)
  • All tests pass
  • Component renders with realtime preview (useMemo)

Tool 5: マークダウンプレビュー (markdown-preview)

File Structure

src/tools/markdown-preview/
├── meta.ts
├── logic.ts
├── Component.tsx
├── Component.module.css
└── __tests__/
    └── logic.test.ts

meta.ts

import type { ToolMeta } from "@/tools/types";

export const meta: ToolMeta = {
  slug: "markdown-preview",
  name: "Markdownプレビュー",
  nameEn: "Markdown Preview",
  description:
    "Markdownプレビューツール。Markdownテキストをリアルタイムでプレビュー表示。見出し、リスト、テーブル、コードブロック等に対応。登録不要・無料で使えるオンラインツールです。",
  shortDescription: "MarkdownテキストをリアルタイムでHTML表示",
  keywords: [
    "Markdown プレビュー",
    "マークダウン エディタ オンライン",
    "Markdownプレビュー",
    "Markdown変換",
    "Markdownエディタ",
  ],
  category: "developer",
  relatedSlugs: ["json-formatter", "html-entity", "regex-tester"],
  publishedAt: "2026-02-14",
  structuredDataType: "WebApplication",
};

logic.ts

Important: marked is already in dependencies (v17.0.2). It must be imported carefully because marked v17 uses ESM. The logic.ts should handle sanitization since we render HTML.

import { marked } from "marked";
import type { MarkedOptions } from "marked";

export interface MarkdownResult {
  success: boolean;
  html: string;
  error?: string;
}

const MAX_INPUT_LENGTH = 50_000;

// Configure marked options (no external dependencies for sanitization)
const markedOptions: MarkedOptions = {
  gfm: true, // GitHub Flavored Markdown
  breaks: true, // Convert \n to <br>
};

// Basic HTML sanitizer: remove <script>, on* attributes, javascript: URLs
// This is defense-in-depth since marked itself does not execute scripts,
// but the output is rendered via dangerouslySetInnerHTML.
function sanitizeHtml(html: string): string {
  return (
    html
      // Remove <script> tags and contents
      .replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, "")
      // Remove on* event handlers
      .replace(/\s+on\w+\s*=\s*(?:"[^"]*"|'[^']*'|[^\s>]+)/gi, "")
      // Remove javascript: URLs
      .replace(/href\s*=\s*["']?\s*javascript:/gi, 'href="')
      // Remove <iframe>, <embed>, <object>
      .replace(/<(iframe|embed|object)\b[^>]*>.*?<\/\1>/gi, "")
      .replace(/<(iframe|embed|object)\b[^>]*\/?>/gi, "")
  );
}

export function renderMarkdown(input: string): MarkdownResult {
  if (input.length > MAX_INPUT_LENGTH) {
    return {
      success: false,
      html: "",
      error: `入力テキストが長すぎます（最大${MAX_INPUT_LENGTH.toLocaleString()}文字）`,
    };
  }

  try {
    const rawHtml = marked.parse(input, markedOptions) as string;
    const html = sanitizeHtml(rawHtml);
    return { success: true, html };
  } catch (e) {
    return {
      success: false,
      html: "",
      error: e instanceof Error ? e.message : "Markdown parsing failed",
    };
  }
}

// Export for testing
export { sanitizeHtml };

Component.tsx (Outline)

"use client";

import { useState, useMemo } from "react";
import { renderMarkdown } from "./logic";
import styles from "./Component.module.css";

const SAMPLE_MARKDOWN = `# Heading 1
## Heading 2

This is **bold** and *italic* text.

- List item 1
- List item 2

\`\`\`javascript
console.log("Hello");
\`\`\`

| Column A | Column B |
|----------|----------|
| Cell 1   | Cell 2   |
`;

export default function MarkdownPreviewTool() {
  const [input, setInput] = useState(SAMPLE_MARKDOWN);

  const result = useMemo(() => renderMarkdown(input), [input]);

  // Layout: side-by-side panels (same as json-formatter's panels pattern)
  // Left panel: textarea for Markdown input
  // Right panel: rendered HTML preview (dangerouslySetInnerHTML)
  // Error display if any
  // The preview panel uses a .prose class for typography styling

  return (
    <div className={styles.container}>
      <div className={styles.panels}>
        <div className={styles.panel}>
          <label htmlFor="md-input" className={styles.panelLabel}>
            Markdown
          </label>
          <textarea
            id="md-input"
            className={styles.textarea}
            value={input}
            onChange={(e) => setInput(e.target.value)}
            placeholder="Markdownを入力..."
            spellCheck={false}
          />
        </div>
        <div className={styles.panel}>
          <span className={styles.panelLabel}>プレビュー</span>
          {result.error ? (
            <div className={styles.error} role="alert">{result.error}</div>
          ) : (
            <div
              className={styles.preview}
              dangerouslySetInnerHTML={{ __html: result.html }}
            />
          )}
        </div>
      </div>
    </div>
  );
}

Component.module.css

json-formatter の panels パターンを踏襲 + .preview に prose-like typographyスタイリングを追加:

.container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.panels {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

@media (max-width: 768px) {
  .panels {
    grid-template-columns: 1fr;
  }
}

.panel {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.panelLabel {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
}

.textarea {
  width: 100%;
  min-height: 400px;
  padding: 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.5;
  resize: vertical;
  color: var(--color-text);
  background-color: var(--color-bg);
}

.textarea:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: -1px;
  border-color: var(--color-primary);
}

.preview {
  min-height: 400px;
  padding: 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
  background-color: var(--color-bg);
  overflow-y: auto;
  line-height: 1.7;
}

/* Prose typography for rendered markdown */
.preview h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0.5em 0;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 0.3em;
}
.preview h2 {
  font-size: 1.3rem;
  font-weight: 600;
  margin: 0.5em 0;
}
.preview h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0.5em 0;
}
.preview p {
  margin: 0.5em 0;
}
.preview ul,
.preview ol {
  padding-left: 1.5em;
  margin: 0.5em 0;
}
.preview li {
  margin: 0.25em 0;
}
.preview code {
  background-color: var(--color-bg-secondary);
  padding: 0.15em 0.3em;
  border-radius: 0.25rem;
  font-size: 0.85em;
}
.preview pre {
  background-color: var(--color-bg-secondary);
  padding: 0.75rem;
  border-radius: 0.5rem;
  overflow-x: auto;
}
.preview pre code {
  background: none;
  padding: 0;
}
.preview blockquote {
  border-left: 3px solid var(--color-border);
  padding-left: 0.75rem;
  color: var(--color-text-muted);
  margin: 0.5em 0;
}
.preview table {
  border-collapse: collapse;
  width: 100%;
  margin: 0.5em 0;
}
.preview th,
.preview td {
  border: 1px solid var(--color-border);
  padding: 0.4rem 0.6rem;
  text-align: left;
}
.preview th {
  background-color: var(--color-bg-secondary);
  font-weight: 600;
}
.preview a {
  color: var(--color-primary);
}
.preview img {
  max-width: 100%;
}
.preview hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 1em 0;
}

.error {
  padding: 0.75rem;
  border: 1px solid var(--color-error);
  border-radius: 0.5rem;
  background-color: var(--color-error-bg);
  color: var(--color-error);
  font-size: 0.85rem;
}

Test Plan (__tests__/logic.test.ts)

import { describe, test, expect } from "vitest";
import { renderMarkdown, sanitizeHtml } from "../logic";

describe("renderMarkdown", () => {
  test("renders heading", () => {
    const r = renderMarkdown("# Hello");
    expect(r.success).toBe(true);
    expect(r.html).toContain("<h1>");
    expect(r.html).toContain("Hello");
  });

  test("renders bold and italic", () => {
    const r = renderMarkdown("**bold** and *italic*");
    expect(r.success).toBe(true);
    expect(r.html).toContain("<strong>bold</strong>");
    expect(r.html).toContain("<em>italic</em>");
  });

  test("renders unordered list", () => {
    const r = renderMarkdown("- item1\n- item2");
    expect(r.success).toBe(true);
    expect(r.html).toContain("<li>");
  });

  test("renders code block", () => {
    const r = renderMarkdown("```\ncode\n```");
    expect(r.success).toBe(true);
    expect(r.html).toContain("<code>");
  });

  test("renders table (GFM)", () => {
    const r = renderMarkdown("| A | B |\n|---|---|\n| 1 | 2 |");
    expect(r.success).toBe(true);
    expect(r.html).toContain("<table>");
  });

  test("renders inline code", () => {
    const r = renderMarkdown("use `npm install`");
    expect(r.success).toBe(true);
    expect(r.html).toContain("<code>npm install</code>");
  });

  test("renders links", () => {
    const r = renderMarkdown("[link](https://example.com)");
    expect(r.success).toBe(true);
    expect(r.html).toContain('href="https://example.com"');
  });

  test("handles empty string", () => {
    const r = renderMarkdown("");
    expect(r.success).toBe(true);
    expect(r.html).toBe("");
  });

  test("rejects input exceeding max length", () => {
    const r = renderMarkdown("a".repeat(50_001));
    expect(r.success).toBe(false);
    expect(r.error).toBeDefined();
  });
});

describe("sanitizeHtml", () => {
  test("removes script tags", () => {
    expect(sanitizeHtml('<script>alert("xss")</script>')).toBe("");
  });

  test("removes onclick attributes", () => {
    const input = '<div onclick="alert(1)">click</div>';
    const output = sanitizeHtml(input);
    expect(output).not.toContain("onclick");
  });

  test("removes javascript: URLs", () => {
    const input = '<a href="javascript:alert(1)">click</a>';
    const output = sanitizeHtml(input);
    expect(output).not.toContain("javascript:");
  });

  test("preserves safe HTML", () => {
    const input = "<h1>Hello</h1><p>World</p>";
    expect(sanitizeHtml(input)).toBe(input);
  });
});

Acceptance Criteria

  • renderMarkdown() uses marked v17 to parse GFM markdown
  • Headings, bold, italic, lists, code blocks, tables, links, images, blockquotes all render
  • sanitizeHtml() removes script tags, on* attributes, javascript: URLs, iframe/embed/object
  • Input length guard (50,000 chars max)
  • All tests pass
  • Component renders side-by-side editor/preview (responsive: stacks on mobile)
  • Preview area has proper typography styling

Registry Updates

registry.ts additions

5 new imports and 5 new entries. Each builder adds their tool's entry independently. To minimize merge conflicts, each builder appends at the end of both sections.

// Add these imports (each builder adds their own)
import { meta as fullwidthConverterMeta } from "./fullwidth-converter/meta";
import { meta as colorConverterMeta } from "./color-converter/meta";
import { meta as htmlEntityMeta } from "./html-entity/meta";
import { meta as textReplaceMeta } from "./text-replace/meta";
import { meta as markdownPreviewMeta } from "./markdown-preview/meta";

// Add these entries to toolEntries array (each builder appends at the end)
  {
    meta: fullwidthConverterMeta,
    componentImport: () => import("./fullwidth-converter/Component"),
  },
  {
    meta: colorConverterMeta,
    componentImport: () => import("./color-converter/Component"),
  },
  {
    meta: htmlEntityMeta,
    componentImport: () => import("./html-entity/Component"),
  },
  {
    meta: textReplaceMeta,
    componentImport: () => import("./text-replace/Component"),
  },
  {
    meta: markdownPreviewMeta,
    componentImport: () => import("./markdown-preview/Component"),
  },

relatedSlugs Design

New tools' relatedSlugs (defined above in each meta.ts)

Tool relatedSlugs
fullwidth-converter char-count, text-replace, text-diff
color-converter json-formatter, regex-tester, markdown-preview
html-entity url-encode, base64, markdown-preview
text-replace char-count, fullwidth-converter, regex-tester, text-diff
markdown-preview json-formatter, html-entity, regex-tester

Existing tools that should add new relatedSlugs (optional, low priority)

Existing Tool Add to relatedSlugs
char-count fullwidth-converter, text-replace
text-diff fullwidth-converter, text-replace
regex-tester text-replace
url-encode html-entity
base64 html-entity
json-formatter color-converter, markdown-preview

Note: Updating existing tools' relatedSlugs is optional for this batch and can be done as a follow-up to avoid touching files being used by other tools.

Parallel Implementation Strategy

Conflict-free Work Areas

Each tool is entirely self-contained in src/tools/<slug>/. The only shared file is registry.ts.

Builder Assignment Recommendation

Builder Tools Rationale
Builder A fullwidth-converter, text-replace Both text category, similar patterns
Builder B color-converter, markdown-preview Both developer category, more complex UI
Builder C html-entity encoding category, simple pattern (base64 clone)

registry.ts Conflict Avoidance

Strategy: Each builder completes their tool directory first. The last step of each builder's work is to add their import + entry to registry.ts. Since git merges line additions at different positions well, the risk is low.

Specific instructions for builders:

  1. Create all files in src/tools/<slug>/ first
  2. Run tests: NODE_EXTRA_CA_CERTS=~/.Zscaler.pem npx vitest run src/tools/<slug>/
  3. Commit the tool directory
  4. Then add import + entry to registry.ts (import at end of import block, entry at end of array)
  5. Commit registry.ts change
  6. Run NODE_EXTRA_CA_CERTS=~/.Zscaler.pem npm run build to verify no build errors

Fallback: If merge conflicts occur in registry.ts, they will be trivial to resolve (just keep all additions).

Existing relatedSlugs Updates

Defer to a separate follow-up task after all 5 tools are merged. This avoids touching files that might conflict with other work.

Rollback Approach

Each tool is isolated in its own directory. Rollback for any tool:

  1. git revert the registry.ts commit
  2. git revert the tool directory commit
  3. Or simply remove the directory and registry entry

No schema migrations, no database changes, no external service dependencies.

Next Actions

  1. Project manager to create 2-3 builder task memos based on this plan
  2. Builders implement tools in parallel (each builder gets 1-3 tools)
  3. Each builder runs tests and build verification
  4. Reviewer checks completed tools
  5. Follow-up task: update existing tools' relatedSlugs