premark

Imported from zxch3n/premark (AGENTS.md). Install upstream with npx skills add zxch3n/premark. Copyright stays with the author.

• 你正在协助的对象是 Zixuan。
• 假设 Zixuan 是一名经验丰富的资深前端工程师，熟悉 CRDTs、富文本编辑器，实时协作计数，熟悉 Rust、JS、TS 等主流语言及其生态。
• 对于前端 Zixuan 的技术偏好是 React, Tanstack, Tailwind, Vite, Vitest, Tsdown, Oxlint, Oxfmt。
• 你说的话需要少用黑话，少用行话，尽量用简单词来描述，但要追求语言准确。

Premark Native Editor Invariants

When working on the native Markdown editor, reread plans/2026-04-20_premark-native-editor-redesign.md first if context was compacted or if you are changing editor architecture.

Core invariants:

• Markdown source offsets are authoritative. DOM selection, textarea value, rendered text, and Canvas paint positions are never the source of truth.
• Every caret, selection rect, hit-test result, active Markdown control, composition preedit, and Canvas text paint position must map back to source offsets.
• Grapheme boundaries are the smallest editable text boundary. Never place a caret or deletion range inside a grapheme cluster.
• Text measurement, editable geometry, and Canvas painting must share the same boundary model. Do not add a Canvas-only width heuristic.
• Source-mode editing preserves every \n as a visual line advance.
• Source-mode parsing preserves line-leading spaces as editable text and does not treat 4-space indentation as an implicit code block; fenced code remains the explicit code-block syntax.
• When the caret or selection touches a table block or image source line, only that table/image range renders as plain Markdown source text; other tables/images keep normal rendering.
• Hidden textarea state is only an OS input bridge. It must not overwrite native composition state while IME is active.
• Active Markdown controls and composition are render views over the same source, not separate documents.
• Remote/AI patches must go through explicit source patch APIs and must not enter local undo history.

Architecture decisions:

• Keep CodeMirror overlay out of the product path.
• Keep browser input hosting reusable; do not duplicate hidden textarea, IME, clipboard, pointer, or keyboard logic across DOM and Canvas stories.
• Keep PremarkEditorController as the product-facing API; layout/editable internals may change behind render snapshots.
• Font readiness is correctness-sensitive. If a change can affect measureText, layout and editable geometry must be invalidated or rebuilt.

Testing ladder:

• Prefer pure tests for parser/layout/editable geometry, grapheme boundaries, Markdown behavior, remote patch rebasing, and performance invariants.
• Use Playwright Chromium for Storybook wiring, browser event smoke, screenshots, and visual parity.
• Use Playwright WebKit as a fast WebKit proxy only; it is not proof of real Safari or real IME behavior.
• Use Safari WebDriver for isolated Safari behavior; do not use it as proof of foreground OS input.
• Use tests/real-interactions for foreground keyboard, clipboard, double/triple click, and HID drag behavior that Playwright cannot prove.
• Use tests/macos-ime for real macOS IME. It must gate on unlocked session, foreground browser, input source readiness, and HID reachability before sending global input.

Using Vite+, the Unified Toolchain for the Web

This project is using Vite+, a unified toolchain built on top of Vite, Rolldown, Vitest, tsdown, Oxlint, Oxfmt, and Vite Task. Vite+ wraps runtime management, package management, and frontend tooling in a single global CLI called vp. Vite+ is distinct from Vite, but it invokes Vite through vp dev and vp build.

Vite+ Workflow

vp is a global binary that handles the full development lifecycle. Run vp help to print a list of commands and vp <command> --help for information about a specific command.

Start

• create - Create a new project from a template
• migrate - Migrate an existing project to Vite+
• config - Configure hooks and agent integration
• staged - Run linters on staged files
• install (i) - Install dependencies
• env - Manage Node.js versions

Develop

• dev - Run the development server
• check - Run format, lint, and TypeScript type checks
• lint - Lint code
• fmt - Format code
• test - Run tests

Execute

• run - Run monorepo tasks
• exec - Execute a command from local node_modules/.bin
• dlx - Execute a package binary without installing it as a dependency
• cache - Manage the task cache

Build

• build - Build for production
• pack - Build libraries
• preview - Preview production build

Manage Dependencies

Vite+ automatically detects and wraps the underlying package manager such as pnpm, npm, or Yarn through the packageManager field in package.json or package manager-specific lockfiles.

• add - Add packages to dependencies
• remove (rm, un, uninstall) - Remove packages from dependencies
• update (up) - Update packages to latest versions
• dedupe - Deduplicate dependencies
• outdated - Check for outdated packages
• list (ls) - List installed packages
• why (explain) - Show why a package is installed
• info (view, show) - View package information from the registry
• link (ln) / unlink - Manage local package links
• pm - Forward a command to the package manager

Maintain

• upgrade - Update vp itself to the latest version

These commands map to their corresponding tools. For example, vp dev --port 3000 runs Vite's dev server and works the same as Vite. vp test runs JavaScript tests through the bundled Vitest. The version of all tools can be checked using vp --version. This is useful when researching documentation, features, and bugs.

Common Pitfalls

• Using the package manager directly: Do not use pnpm, npm, or Yarn directly. Vite+ can handle all package manager operations.
• Always use Vite commands to run tools: Don't attempt to run vp vitest or vp oxlint. They do not exist. Use vp test and vp lint instead.
• Running scripts: Vite+ built-in commands (vp dev, vp build, vp test, etc.) always run the Vite+ built-in tool, not any package.json script of the same name. To run a custom script that shares a name with a built-in command, use vp run <script>. For example, if you have a custom dev script that runs multiple services concurrently, run it with vp run dev, not vp dev (which always starts Vite's dev server).
• Do not install Vitest, Oxlint, Oxfmt, or tsdown directly: Vite+ wraps these tools. They must not be installed directly. You cannot upgrade these tools by installing their latest versions. Always use Vite+ commands.
• Use Vite+ wrappers for one-off binaries: Use vp dlx instead of package-manager-specific dlx/npx commands.
• Import JavaScript modules from vite-plus: Instead of importing from vite or vitest, all modules should be imported from the project's vite-plus dependency. For example, import { defineConfig } from 'vite-plus'; or import { expect, test, vi } from 'vite-plus/test';. You must not install vitest to import test utilities.
• Type-Aware Linting: There is no need to install oxlint-tsgolint, vp lint --type-aware works out of the box.

CI Integration

For GitHub Actions, consider using voidzero-dev/setup-vp to replace separate actions/setup-node, package-manager setup, cache, and install steps with a single action.

- uses: voidzero-dev/setup-vp@v1
  with:
    cache: true
- run: vp check
- run: vp test

Review Checklist for Agents

• Run vp install after pulling remote changes and before getting started.
• Run vp check and vp test to validate changes.