✨ feat: generate DOCX directly from Markdown

[135yshr]

概要

DOCX出力を HTML経由ではなく Markdown から pandoc の gfm リーダーで直変換 するように変更しました。これにより pandoc が HTML 由来の雑多なスタイルではなく、クリーンな Word ネイティブの段落・リストスタイルを生成します。

人間が手作業で作った読みやすい docx と比較したところ、読みにくさの主因は (1) HTML 経由による構造の乱れ、(2) 日本語フォント未指定（テーマの East Asian typeface が空でフォールバック）でした。本変更で両方を解消します。

変更点

• パイプラインの早期分岐 — Convert() で format を判定し、DOCX は HTML を構築せず convertMarkdownDOCX へ。PDF パスは従来どおり（HTML → Chromium）
• mermaid_markdown.go（新規） — 生 Markdown を行走査して ```mermaid フェンスを抽出（他のフェンスは保持）、レンダリングした PNG を ![](…) 画像参照として差し戻し
• 参照ドキュメントの整形 — 読みやすい日本語出力のため、游ゴシック（テーマフォント）/ 本文 10.5pt / コンパクトな見出し / 既存のテーブル罫線を適用。-docx-font でフォント変更可
• Mermaid PNG スケールを 2 → 4 に引き上げ — 埋め込み図の解像度が縦横2倍（例: 216×556 → 432×1112 px）に向上
• 画像解決 — ユーザー画像は --resource-path、生成図は cmd.Dir（作業ディレクトリ）で解決

テスト

• extractMermaidFromMarkdown / フェンス解析 / 参照ドキュメント整形ヘルパー（setThemeFonts・setBodyFontSize・shrinkHeadings）のユニットテストを追加
• 既存の convertDOCX テストを新 API（convertMarkdownDOCX）に更新
• go build / go vet / gofmt / 全テスト緑、PDF 統合テストも回帰なし
• 実際に DOCX を生成し、テーマフォント=游ゴシック・本文 sz=21・見出し H1=32/H2=26/H3=24・罫線あり・Mermaid PNG 埋め込みを確認

ドキュメント

• CLAUDE.md / README.md を新しい2系統パイプラインに合わせて更新

Summary by CodeRabbit

• New Features

  • Added -docx-font CLI option to customize font family for DOCX output (defaults to Yu Gothic for East Asian text support).

• Improvements

  • DOCX output now features enhanced styling: visible table borders, optimized font sizing, and improved heading layout.
  • Mermaid diagrams in DOCX now render as PNG images for better Word compatibility.

• Documentation

  • Updated README and architecture documentation to clarify distinct PDF and DOCX conversion workflows.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: db8bd6e1-c0f0-41e6-bb4c-90ee21889041

📥 Commits

Reviewing files that changed from the base of the PR and between d15ec16 and a78ed7c.

📒 Files selected for processing (9)

• CLAUDE.md
• README.md
• cmd/md2pdf/flags.go
• internal/converter/converter.go
• internal/converter/docx.go
• internal/converter/docx_test.go
• internal/converter/mermaid.go
• internal/converter/mermaid_markdown.go
• internal/converter/mermaid_markdown_test.go

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📝 Walkthrough

Walkthrough

The DOCX conversion pipeline is replaced from an HTML-intermediate approach to a direct Markdown-to-pandoc (gfm) path. Mermaid fenced blocks are extracted from raw Markdown, rendered to PNGs, and injected back as image references before pandoc runs. The renderMermaid function is simplified to SVG-only (for PDF). A new -docx-font flag controls reference-doc theme fonts, and OOXML patching is expanded to cover body font size, heading compaction, and Latin/East-Asian font theming.

Changes

DOCX Pipeline Overhaul

Layer / File(s)	Summary
Markdown Mermaid fence extraction internal/converter/mermaid_markdown.go, internal/converter/mermaid_markdown_test.go	New file implementing CommonMark-compliant fenced-block scanning via extractMermaidFromMarkdown, parseFenceOpen, isFenceClose, and stripCodeIndent; full table-driven test coverage for extraction, ordering, fence detection, and closing rules.
renderMermaid simplified to SVG-only internal/converter/mermaid.go	Removes the docx-format conditional PNG branch from renderMermaid so it always populates block.SVGContent; bumps mermaidPNGScale from "2" to "4"; removes the strings import.
DOCXFont config field, CLI flag, and Convert orchestration internal/converter/converter.go, cmd/md2pdf/flags.go	Adds DOCXFont field to Config; wires -docx-font flag in parseFlags/printUsage; restructures Converter.Convert to resolve paths up front and perform an early-return DOCX branch, leaving the PDF path (image copy → printPDF) for non-DOCX formats.
convertMarkdownDOCX: Markdown → PNG injection → pandoc internal/converter/docx.go, internal/converter/docx_test.go	Implements convertMarkdownDOCX (extract Mermaid blocks, render PNGs via renderMermaidPNGs, rewrite placeholders to image refs, write document.md, call buildReferenceDoc, invoke pandoc with -f gfm and --resource-path); adds docxFont selector; tests assert pandoc CLI args and error propagation.
DOCX reference-doc OOXML patching internal/converter/docx.go, internal/converter/docx_test.go	Replaces the single table-border patcher with patchReferenceDoc transforming both word/styles.xml (addTableBorders, setBodyFontSize, shrinkHeadings) and word/theme/theme1.xml (setThemeFonts); refactors rewriteDocxEntries to use a per-entry transform map; tests cover each OOXML helper.
README and CLAUDE.md docs README.md, CLAUDE.md	Adds -docx-font to the Options table; rewrites the How It Works flowchart and bullets for both PDF and DOCX branches; rewrites CLAUDE.md architecture section for the separated pipelines and new Config fields.

Sequence Diagram(s)

sequenceDiagram
    actor CLI as CLI (-docx-font flag)
    participant Conv as Converter.Convert
    participant MDOCX as convertMarkdownDOCX
    participant Extract as extractMermaidFromMarkdown
    participant Mmdc as renderMermaidPNGs (mmdc)
    participant RefDoc as buildReferenceDoc + patchReferenceDoc
    participant Pandoc as pandoc (gfm reader)

    CLI->>Conv: Convert(inputMD, outputPath)
    Conv->>Conv: resolve srcDir, absOut
    Conv->>MDOCX: mdBytes, srcDir, absOut
    MDOCX->>Extract: raw Markdown bytes
    Extract-->>MDOCX: rewritten Markdown + mermaid block map
    MDOCX->>Mmdc: render each block → workDir/*.png
    Mmdc-->>MDOCX: PNG paths
    MDOCX->>MDOCX: replace placeholders with ![img](path) refs
    MDOCX->>MDOCX: write document.md to workDir
    MDOCX->>RefDoc: pandoc --print-default-data-file reference.docx
    RefDoc->>RefDoc: patchReferenceDoc (styles.xml + theme1.xml rewrites)
    RefDoc-->>MDOCX: reference.docx written to workDir
    MDOCX->>Pandoc: -f gfm document.md -o out.docx --reference-doc --resource-path
    Pandoc-->>Conv: DOCX output file

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Estimated code review effort

🎯 4 (Complex) | ⏱️ ~60 minutes

Possibly related PRs

• 135yshr/md2pdf#4: Introduced CLAUDE.md, which this PR rewrites to reflect the new PDF/DOCX pipeline architecture.
• 135yshr/md2pdf#33: Directly precedes this PR's changes to mermaid.go's DOCX rendering branch (PNG vs SVG) and the DOCX conversion path.

Poem

🐇 Hop, hop through Markdown land,
No more HTML middle-man!
Mermaid blocks turn PNG-bright,
Pandoc conjures DOCX right.
Yu Gothic fonts align in rows—
The rabbit types, and off it goes! ✨

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/docx-markdown-native

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

Error: can't load config: unsupported version of the configuration: "" See https://golangci-lint.run/docs/product/migration-guide for migration instructions
The command is terminated due to an error: can't load config: unsupported version of the configuration: "" See https://golangci-lint.run/docs/product/migration-guide for migration instructions

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