@stencil/cli

CLI for Stencil — build, test, and generate web components.

Install

npm install --save-dev @stencil/cli @stencil/core

Usage

# Build
npx stencil build

# Build in watch mode
npx stencil build --watch

# Run tests
npx stencil test --spec
npx stencil test --e2e

# Generate a new component
npx stencil generate my-component

# Start dev server
npx stencil build --dev --watch --serve

Programmatic API

run(init) — invoke the CLI from code

Mirrors running stencil <task> in the terminal. Parse your own args array and Stencil handles the rest.

import { run } from '@stencil/cli';
import { createNodeLogger, createNodeSys } from '@stencil/core/sys/node';

await run({
  args: ['build', '--dev', '--watch'],
  logger: createNodeLogger(),
  sys: createNodeSys(),
});

runTask(coreCompiler, config, task, sys, flags?) — lower-level task execution

Use this when you need control over the compiler instance or config before running a task. You are responsible for loading the compiler and config yourself.

import * as coreCompiler from '@stencil/core/compiler';
import { runTask, createConfigFlags } from '@stencil/cli';
import { createNodeLogger, createNodeSys } from '@stencil/core/sys/node';

const logger = createNodeLogger();
const sys = createNodeSys();

// Load and validate stencil.config.ts
const { config, diagnostics } = await coreCompiler.loadConfig({
  configPath: './stencil.config.ts',
  logger,
  sys,
});
if (diagnostics.length) logger.printDiagnostics(diagnostics);

// Optional: override config flags (e.g. force dev mode)
const flags = createConfigFlags({ task: 'build', dev: true });

await runTask(coreCompiler, config, 'build', sys, flags);

Valid task values: 'build' | 'docs' | 'generate' | 'serve' | 'prerender' | 'test' | 'info' | 'migrate' | 'init' | 'add' | 'telemetry'

flags is optional — if omitted, defaults are derived from the task.