---
name: wix-cli-app-validation
description: Use when testing app readiness, verifying runtime behavior, or validating before releases and after changes in the code. Triggers include validate, test, verify, check readiness, preview validation, build verification, TypeScript compilation.
compatibility: Requires Wix CLI development environment.
---

# Wix App Validation

Validates Wix CLI applications through a four-step sequential workflow: package installation, TypeScript compilation check, build, and preview.

## Validation Workflow

Execute these steps sequentially. Stop and report errors if any step fails.

### Step 1: Package Installation

Ensure all dependencies are installed before proceeding with the build.

**Detect package manager:**
- Check for `package-lock.json` → use `npm`
- Check for `yarn.lock` → use `yarn`
- Check for `pnpm-lock.yaml` → use `pnpm`
- Default to `npm` if no lock file is found

**Run installation command:**

```bash
# For npm
npm install

# For yarn
yarn install

# For pnpm
pnpm install
```

**Success criteria:**
- Exit code 0
- All dependencies installed successfully
- No missing peer dependencies warnings (unless expected)
- `node_modules` directory exists and contains expected packages

**On failure:** Report the installation errors, [check the debug log](#debug-log-on-errors) for detailed diagnostics, and stop validation. Common issues:
- Network connectivity problems
- Corrupted lock files
- Version conflicts
- Missing Node.js or package manager

### Step 2: TypeScript Compilation Check

Run TypeScript compiler to check for type errors.

**Full project check:**
```bash
npx tsc --noEmit
```

**Targeted check (specific files/directories):**

When validating after implementing a specific extension, you can run TypeScript checks on just those files:

```bash
# Check specific directory
npx tsc --noEmit src/extensions/dashboard/pages/survey/**/*.ts src/extensions/dashboard/pages/survey/**/*.tsx

# Check dashboard pages only
npx tsc --noEmit src/extensions/dashboard/pages/**/*.ts src/extensions/dashboard/pages/**/*.tsx

# Check site widgets only
npx tsc --noEmit src/extensions/site/widgets/**/*.ts src/extensions/site/widgets/**/*.tsx

# Check dashboard modals only
npx tsc --noEmit src/extensions/dashboard/modals/**/*.ts src/extensions/dashboard/modals/**/*.tsx

# Check backend only
npx tsc --noEmit src/extensions/backend/**/*.ts
```

**When to use targeted checks:**
- After implementing a single extension (faster feedback)
- When debugging type errors in a specific area
- During iterative development

**When to use full project check:**
- Before final validation
- When changes affect shared types
- Before building/deploying

**Success criteria:**
- Exit code 0
- No TypeScript compilation errors
- All type checks pass

**On failure:** Report the specific TypeScript errors and stop validation. Common issues:
- Type mismatches between expected and actual types
- Missing type declarations for imported modules
- Incorrect generic type parameters
- Properties not existing on declared types
- Incompatible function signatures

### Step 3: Build Validation

Run the build command and check for compilation errors:

```bash
npx wix build
```

**Success criteria:**
- Exit code 0
- No TypeScript errors
- No missing dependencies

**On failure:** Report the specific compilation errors, [check the debug log](#debug-log-on-errors) for detailed diagnostics, and stop validation.

### Step 4: Preview Deployment

Start the preview server:

```bash
npx wix preview
```

**Success criteria:**
- Preview server starts successfully
- Preview URLs are generated (both site and dashboard)

**URL extraction:** Parse the terminal output to find both preview URLs. Look for patterns like:
- Site preview: `Site preview: https://...` or `Site URL: https://...`
- Dashboard preview: `Dashboard preview: https://...` or `Preview URL: https://...` or `Your app is available at: https://...`

Extract both URLs and provide them to the user for manual verification.

**On failure:** Report the preview startup errors, [check the debug log](#debug-log-on-errors) for detailed diagnostics, and stop validation.

## Validation Report

After completing all steps, provide a summary:

**Pass:**
- Dependencies: ✓ All packages installed successfully
- TypeScript: ✓ No compilation errors
- Build: ✓ Compiled successfully
- Preview: ✓ Running at [URL]

**Fail:**
- Identify which step failed
- Provide specific error messages
- Suggest remediation steps

## Debug Log on Errors

When a validation step fails (non-zero exit code, error output, or the CLI crashes/hangs), check `.wix/debug.log` in the project root for the full error trace. **Only read this file when errors occur** — skip it when steps pass or when the terminal output already makes the error clear (e.g. a straightforward TypeScript type error).

The `.wix/` directory is automatically created by the Wix CLI and contains internal configuration and log files. Don't edit it, but reading `debug.log` for troubleshooting is expected.

```
Read: .wix/debug.log

# If the file is large, read the last 100 lines for the most recent errors
Read: .wix/debug.log (with offset to the end)
```

## Common Issues

| Issue | Cause | Solution |
|-------|-------|----------|
| Package installation fails | Missing lock file, network issues, or corrupted node_modules | Delete `node_modules` and lock file, then reinstall |
| TypeScript compilation fails | Type mismatches, missing declarations, or incorrect types | Fix TypeScript errors shown in `npx tsc --noEmit` output |
| Build fails | TypeScript errors, missing dependencies, or internal CLI error | Fix TypeScript errors in source; for non-obvious failures, check `.wix/debug.log` |
| Preview fails to start | Port conflict, config issue, or internal CLI error | Check `wix.config.json`; if unclear, check `.wix/debug.log` for details |
| Console errors in preview | Runtime exceptions | Check browser console output |
| UI not rendering | Component errors | Review component code and imports |
| CLI error with no clear message | Truncated terminal output | Read `.wix/debug.log` for the full error trace and stack details |
| Mysterious failures after config change | Stale CLI state | Read `.wix/debug.log` to confirm, then delete `.wix/` and rebuild |