Web Development

SKILL.md

---
name: web-development
description: Use when users need to implement, integrate, debug, build, deploy, or validate a Web frontend after the product direction is already clear, especially for React, Vue, Vite, browser flows, or CloudBase Web integration.
version: 2.23.8
alwaysApply: false
---

## Standalone Install Note

If this environment only installed the current skill, start from the CloudBase main entry and use the published `cloudbase/references/...` paths for sibling skills.

- CloudBase main entry: `https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/SKILL.md`
- Current skill raw source: `https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/web-development/SKILL.md`

Keep local `references/...` paths for files that ship with the current skill directory. When this file points to a sibling skill such as `auth-tool` or `web-development`, use the standalone fallback URL shown next to that reference.

**Cross-cutting protocols** (required before code changes or static hosting publish):
- Change Safety Protocol: `https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/cloudbase-platform/references/protocols/change-safety-protocol.md`
- Deployment Gate: `https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/cloudbase-platform/references/protocols/deployment-gate.md`

# Web Development

## Activation Contract

### Use this first when

- The request is to implement, integrate, debug, build, deploy, or validate a Web frontend or static site.
- The design direction is already decided, or the user is asking for engineering execution rather than visual exploration.
- The work involves React, Vue, Vite, routing, browser-based verification, or CloudBase Web integration.

### Read before writing code if

- The task includes project structure, framework conventions, build config, deployment, routing, or frontend test and validation flows.
- The request includes UI implementation but the visual direction is already fixed; otherwise read `ui-design` first.
- **⚠️ Any task involving interface styling, layout, color scheme, or font selection — before writing the first line of CSS/Tailwind, you MUST load the `ui-design` skill and output a Design Specification.** Skipping this step causes frontend styling to degrade to generic AI template defaults. The `ui-design` skill must be loaded before any visual implementation begins, not retroactively after the user complains about the appearance.

### Then also read

- General React / Vue / Vite guidance -> `frameworks.md`
- Browser flow checks or page validation -> `browser-testing.md`
- Login flow -> `../auth-tool/SKILL.md` (standalone fallback: `https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/auth-tool/SKILL.md`), then `../auth-web/SKILL.md` (standalone fallback: `https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/auth-web/SKILL.md`)
- Official Account JSAPI Pay, Native QR-code Pay, or WeChat OAuth on CloudBase -> `../cloudbase-wechat-integration/SKILL.md` (standalone fallback: `https://cnb.cool/tencent/cloud/cloudbase/cloudbase-skills/-/git/raw/main/skills/cloudbase/references/cloudbase-wechat-integration/SKILL.md`; official docs: `https://docs.cloudbase.net/integration/introduce/index.md`)
- CloudBase database work -> matching database skill

### Do NOT use for

- Visual direction setting, prototype-first design work, or pure aesthetic exploration.
- Mini programs, native Apps, or backend-only services.
- WeChat payment or Official Account OAuth contract details; use `cloudbase-wechat-integration` after identifying the Web surface.

### Common mistakes / gotchas

- Starting implementation before clarifying whether the task is design or engineering execution.
- Mixing framework setup, deployment, and CloudBase integration concerns into one vague change.
- Treating cloud functions as the default solution for Web authentication.
- Skipping browser-level validation after a UI or routing change.
- **History mode SPA with CloudBase static hosting**: deploying a single-page app using History mode (React Router / Vue Router) without configuring the static hosting "404 error document" to `index.html`. This causes `NoSuchKey` / 404 errors when users refresh or directly visit any sub-route.
- In an existing application, detouring into UI redesign or broad repo sweeps before patching the current handlers and services.

## Engineering constitution (non-negotiable)

These rules override convenience. Treat them as a gate before saying "done".

### 1. TypeScript — do not silence the type system

- **Do NOT use `any` to bypass type errors.** Not `: any`, not `as any`, not `@ts-ignore`, not `@ts-nocheck`, not `@ts-expect-error` without a written justification. `any` propagates silently and defeats the only compile-time safety net this project has.
- When a type error appears, fix the root cause:
  - Missing / wrong library types → install `@types/...`, or narrow the import, or write a precise `interface` / `type` for the shape you actually use.
  - Shape is genuinely unknown at the boundary (JSON from an API, `postMessage` payload, `window.*` injection) → type it as `unknown` and narrow with a type guard (`typeof`, `in`, a discriminator field, or `zod` / equivalent).
  - Third-party type is wrong → augment via `declare module` in a local `.d.ts`, not `any`.
  - Truly dynamic case (e.g. generic event bus) → use a generic `<T>` with a constraint, not `any`.
- `unknown` + narrowing is the acceptable escape hatch. `any` is not.
- If you genuinely cannot avoid `any` for a specific line (extremely rare), leave a one-line comment with **why** and **what would remove it**, so reviewers can audit.
- The same spirit applies to ESLint: do not sprinkle `// eslint-disable` to mute the real signal. Fix the rule violation, or discuss before disabling.

### 2. Self-verify before claiming done

Before making any non-trivial code or configuration change, you must first follow the Change Safety Protocol in `cloudbase-platform/references/protocols/change-safety-protocol.md` (declare impact → user confirmation → post-edit verification).
Before any static hosting publish or custom domain work, complete the checks in `cloudbase-platform/references/protocols/deployment-gate.md`.

Saying "I've implemented it" / "fixed it" / "it should work" without evidence is not acceptable. Before declaring completion, you must actually run the checks and report the result.

**Static / build layer (always, when applicable):**

- `tsc --noEmit` (or `vue-tsc --noEmit`) passes cleanly — zero errors, zero suppressed diagnostics you added.
- `eslint` / project linter passes on changed files.
- The project's build command (`npm run build` / `pnpm build` / `vite build`) completes without new warnings that you introduced.
- The project's unit tests pass if they exist and cover the touched area.

**Runtime / browser layer (whenever the change affects rendering, routing, forms, auth, or async flows):**

- Use the **`agent-browser`** tool to actually open the page and reproduce the user-visible flow. Follow `browser-testing.md` for the concrete workflow.
- Confirm: the target route loads, the interaction you claim to have fixed behaves the way you claim, no new console errors are introduced, and no regression in the adjacent routes you touched.
- Record what you checked (route, action, expected result, actual result).

**Only after both layers pass** may you say the task is done. If either layer cannot be executed locally (e.g. blocked by credentials, missing backend, paid API), say so explicitly and list exactly which step is still unverified — do not gloss over it.

### 3. Do not paper over failures

- Do not wrap broken logic in `try { ... } catch {}` to make the error go away.
- Do not delete or skip a failing test to make CI green — fix it, or explain why the test is actually wrong and change the test with justification.
- Do not mark a task complete because "the code compiles". Compilation is the bare minimum, not the goal.

## When to use this skill

Use this skill for Web engineering work such as:

- Implementing React or Vue pages and components
- Setting up or maintaining Vite-based frontend projects
- Handling routing, data loading, forms, and build configuration
- Running browser-based validation and smoke checks
- Integrating CloudBase Web SDK and static hosting when the project needs CloudBase capabilities

**Do NOT use for:**
- UI direction or visual system design only; use `ui-design`
- Mini program development; use `miniprogram-development`
- Backend service implementation; use `cloudrun-development` or `cloud-functions`

## How to use this skill (for a coding agent)

1. **Clarify the execution surface**
   - Confirm whether the task is framework setup, page implementation, debugging, deployment, validation, or CloudBase integration.
   - Keep the work scoped to the actual Web app surface instead of spreading into unrelated backend changes.
   - If the workspace is an existing application with TODOs, treat it as a targeted repair task, not a greenfield build.

2. **Follow framework and build conventions**
   - Prefer the existing project stack if one already exists.
   - For new work, treat Vite as the default bundler unless the repo or user constraints say otherwise.
   - Put reusable app code under `src` and build output under `dist` unless the repo already uses a different convention.
   - In an existing application with fixed structure, inspect the files that already own the flow before reading broad docs: `src/lib/backend.*`, `src/lib/auth.*`, `src/lib/*service.*`, route guards, and the page handlers bound to submit buttons.

3. **Validate through the browser, not only by reading code**
   - For interaction, routing, rendering, or regression checks, use `agent-browser` workflows from `browser-testing.md`.
   - Prefer lightweight smoke validation for changed flows before claiming the frontend work is complete.

4. **Treat CloudBase as an integration branch**
   - Use CloudBase Web SDK and static hosting guidance only when the project actually needs CloudBase platform features.
   - Reuse `auth-tool` and `auth-web` for login or provider readiness instead of re-describing those flows here.

## Core workflow

### 1. Choose the right engineering path

- **React / Vue feature work**: implement within the app's existing component, routing, and state conventions
- **New Web app**: prefer Vite unless the repo already standardizes on another toolchain
- **Debugging and regressions**: reproduce in browser, narrow to a specific page or interaction, then patch
- **CloudBase integration**: wire in Web SDK, auth, data, or static hosting only after the base frontend path is clear

### 2. Keep implementation grounded in project reality

- Follow the repo's package manager, scripts, and lint/test patterns
- Avoid framework rewrites unless the user explicitly asks for one
- Prefer the smallest viable page/component/config change that satisfies the task
- In TODO-based apps, complete the existing implementation directly instead of creating parallel helpers, sample pages, or detached prototypes

### 3. Validate changed flows explicitly

- Run the relevant local build / lint / typecheck / test command when available. A clean `tsc --noEmit` and a clean project build are the minimum bar — not proof of correctness.
- For anything user-visible (routing, forms, rendering, auth, async flows), open the affected page or flow in a browser with **`agent-browser`**. Code reading alone is not sufficient evidence — see the Engineering constitution above.
- Record what was checked: route, action, expected result, actual result, and any remaining gap.

## CloudBase Web integration

Use this section only when the Web project needs CloudBase platform features.

### Web SDK rules

- Prefer npm installation for React, Vue, Vite, and other bundler-based projects
- Use the CDN only for static HTML pages, quick demos, embedded snippets, or README examples
- Only use documented CloudBase Web SDK APIs; do not invent methods or options
- Keep a shared `app` or `auth` instance instead of re-initializing on every call
- If the user only provides an environment alias, nickname, or other shorthand, resolve it to the canonical full `EnvId` before writing SDK init code, console links, or config files. Do not pass alias-like short forms directly into `cloudbase.init({ env })`.

### Authentication boundary

- Authentication must use CloudBase SDK built-in features
- Do not move Web login logic into cloud functions
- For provider readiness, login method setup, or publishable key issues, route to `auth-tool` and `auth-web`

### Static hosting defaults

- Build before deployment
- Prefer relative asset paths for static hosting compatibility
- Use hash routing by default when the project lacks server-side route rewrites
- If the user does not specify a root path, avoid deploying directly to the site root by default
- **SPA routing (History mode)**: when using React Router / Vue Router in History mode (not hash mode), configure the CloudBase static hosting **"404 error document"** to `index.html`. Otherwise refreshing or directly visiting any sub-route returns `NoSuchKey` / 404 error, because the static hosting looks for a file at that path instead of falling through to `index.html` for the SPA to handle routing.

  Use the MCP tool to apply this:
  ```json
  manageHosting({ action: "setWebsiteDocument", indexDocument: "index.html", errorDocument: "index.html" })
  ```

  Then verify with:
  ```json
  queryHosting({ action: "websiteConfig" })
  ```

### CloudBase quick start

```js
// npm install @cloudbase/js-sdk
import cloudbase from "@cloudbase/js-sdk";

const app = cloudbase.init({
  env: "your-full-env-id", // Canonical full CloudBase environment ID resolved from envQuery or the console
});

const auth = app.auth
```