// {app_root}/config/plugin.js
exports.withContext = {
  enable: true,
  package: 'egg-plugin-context'
}

// {app_root}/router.js

module.exports = app => {
  const { router, controller, middleware } = app

  router.post('/api/test', middleware.withContext({ token: 100 }), controller.test)
}

// ctx.context.token === 100

// {app_root}/router.js

module.exports = app => {
  const { router, controller, middleware } = app

  router.post(
    '/api/test',
    middleware.withContext(ctx => ({ test: 100 })),
    controller.test
  )
}

// ctx.context.test === 100

// {app_root}/router.js

module.exports = app => {
  const { router, controller, middleware } = app

  router.post(
    '/api/test',
    middleware.withContext(async ctx => Promise.resolve({ test: 100 })),
    controller.test
  )
}

// ctx.context.test === 100

// {app_root}/router.js

module.exports = app => {
  const { router, controller, middleware } = app

  router.post(
    '/api/test',
    middleware.withContext({ token: 100 }, { contextName: 'contextData' }),
    controller.test
  )
}

// ctx.contextData.token === 100