Eager DB client initialization makes the DB required to preview the docs

[benjavicente]

tanstack.com/src/db/client.ts

Lines 5 to 21 in b5379db

	// Create the connection string from environment variable
	const connectionString = process.env.DATABASE_URL
	if (!connectionString) {
	throw new Error('DATABASE_URL environment variable is not set')
	}
	// Create postgres client
	// For serverless environments, use connection pooling
	const client = postgres(connectionString, {
	max: 1, // For serverless, limit connections
	idle_timeout: 20,
	connect_timeout: 10,
	})
	// Create drizzle instance with schema
	export const db = drizzle(client, { schema })

If there is no DB connection set, the build will fail. On docs only contributions, it is annoying.

As a workaround, I'm doing this:

function lazyObject<T extends object>(factory: () => T): T {
  let value: T | undefined = undefined
  return new Proxy({} as T, {
    get(_, prop) {
      if (!value) value = factory()
      return value[prop as keyof T]
    },
  }) as T
}

export const db = lazyObject(() => {
  // Create the connection string from environment variable
  const connectionString = process.env.DATABASE_URL

  if (!connectionString) {
    throw new Error('DATABASE_URL environment variable is not set')
  }

  // Create postgres client
  // For serverless environments, use connection pooling
  const client = postgres(connectionString, {
    max: 1, // For serverless, limit connections
    idle_timeout: 20,
    connect_timeout: 10,
  })

  // Create drizzle instance with schema
  return drizzle(client, { schema })
})

Is that ok for a workaround for a PR, or is there a better pattern or approach? Passing it though the backend context? Or maybe a React's cache like API in start? 🤔

[femincan]

I've encountered the same problem. When I try to run the project it gave Error: DATABASE_URL environment variable is not set error and crashed.

Thank you @benjavicente for your proposed workaround. It helped me to run the project locally.