Files
deer-flow/frontend
Eilen Shin 25fbd25b05 fix(frontend): cap deeply nested list indentation to prevent render crash (#3393) (#3570)
* fix(frontend): cap deeply nested list indentation to prevent render crash

Deeply nested lists make marked's recursive list tokenizer overflow the
call stack during Streamdown's lexing useMemo, throwing an uncaught
"RangeError: Maximum call stack size exceeded" that replaces the chat
route with an error page (issue #3393); on larger stacks the same input
exhausts the heap, which the render error boundary cannot catch.

Mirror the existing capBlockquoteNesting guard with capListNesting, which
clamps leading whitespace to 200 columns (~100 nesting levels) only when
pathologically deep indentation is present, leaving normal content and
fenced code untouched. Wire both through capMarkdownNesting.

* fix(frontend): satisfy prettier format check in preprocess test

* fix(frontend): exempt indented code from list-indent cap (PR #3570 review)

* fix(frontend): keep capping all deep indentation outside fenced code

Revert the indented-code exemption from the PR #3570 review nit. Taken
literally the suggested guard (insideFence || INDENTED_CODE_RE.test(line))
no-ops capListNesting, because INDENTED_CODE_RE matches every line with
4+ leading spaces — i.e. exactly the deep-indent lines the cap targets.
A context-aware exemption (only treat 4+-space lines as code after a
blank line) instead reopens the crash: blank-separated deeply nested list
items get exempted and still blow up marked (verified: OOM at depth ~1.5k).

Unlike blockquotes (markers take <=3 leading spaces, so deep-quote lines
never look like indented code), list vs. indented-code indentation is
ambiguous line-by-line, so any exemption is exploitable. Keep capping all
deep indentation outside fenced code; the only cost is mild corruption of
a >200-column indented-code line, which never occurs in real content and
is strictly preferable to a render crash. Add a regression test locking
the blank-line case.
2026-06-14 22:19:54 +08:00
..
2026-01-14 09:58:53 +08:00
2026-01-24 19:38:08 +08:00
2026-02-10 22:07:25 +08:00

DeerFlow Frontend

Like the original DeerFlow 1.0, we would love to give the community a minimalistic and easy-to-use web interface with a more modern and flexible architecture.

Tech Stack

Quick Start

Prerequisites

  • Node.js 22+
  • pnpm 10.26.2+

Installation

# Install dependencies
pnpm install

# Copy environment variables
cp .env.example .env
# Edit .env with your configuration

Development

# Start development server
pnpm dev

# The app will be available at http://localhost:3000

Build & Test

# Type check
pnpm typecheck

# Check formatting
pnpm format

# Apply formatting
pnpm format:write

# Lint
pnpm lint

# Run unit tests
pnpm test

# One-time setup: install Playwright Chromium browser
pnpm exec playwright install chromium

# Run E2E tests (builds and starts production server automatically)
pnpm test:e2e

# Build for production
pnpm build

# Start production server
pnpm start

Site Map

├── /                    # Landing page
├── /chats               # Chat list
├── /chats/new           # New chat page
└── /chats/[thread_id]   # A specific chat page

Configuration

Environment Variables

Key environment variables (see .env.example for full list):

# Backend API URL (optional, uses local Next.js/nginx proxy by default)
NEXT_PUBLIC_BACKEND_BASE_URL="http://localhost:8001"
# LangGraph-compatible API URL (optional, uses local Next.js/nginx proxy by default)
NEXT_PUBLIC_LANGGRAPH_BASE_URL="http://localhost:8001/api"

Project Structure

tests/
├── e2e/                    # E2E tests (Playwright, Chromium, mocked backend)
└── unit/                   # Unit tests (mirrors src/ layout)
src/
├── app/                    # Next.js App Router pages
│   ├── api/                # API routes
│   ├── workspace/          # Main workspace pages
│   └── mock/               # Mock/demo pages
├── components/             # React components
│   ├── ui/                 # Reusable UI components
│   ├── workspace/          # Workspace-specific components
│   ├── landing/            # Landing page components
│   └── ai-elements/        # AI-related UI elements
├── core/                   # Core business logic
│   ├── api/                # API client & data fetching
│   ├── artifacts/          # Artifact management
│   ├── config/              # App configuration
│   ├── i18n/               # Internationalization
│   ├── mcp/                # MCP integration
│   ├── messages/           # Message handling
│   ├── models/             # Data models & types
│   ├── settings/           # User settings
│   ├── skills/             # Skills system
│   ├── threads/            # Thread management
│   ├── todos/              # Todo system
│   └── utils/              # Utility functions
├── hooks/                  # Custom React hooks
├── lib/                    # Shared libraries & utilities
├── server/                 # Server-side code
│   └── better-auth/        # Authentication setup and session helpers
└── styles/                 # Global styles

Scripts

Command Description
pnpm dev Start development server with Turbopack
pnpm build Build for production
pnpm start Start production server
pnpm test Run unit tests with Vitest
pnpm test:e2e Run E2E tests with Playwright
pnpm format Check formatting with Prettier
pnpm format:write Apply formatting with Prettier
pnpm lint Run ESLint
pnpm lint:fix Fix ESLint issues
pnpm typecheck Run TypeScript type checking
pnpm check Run both lint and typecheck

Development Notes

  • Uses pnpm workspaces (see packageManager in package.json)
  • Turbopack enabled by default in development for faster builds
  • Environment validation can be skipped with SKIP_ENV_VALIDATION=1 (useful for Docker)
  • Backend API URLs are optional; nginx proxy is used by default in development

License

MIT License. See LICENSE for details.