Request to dynamic import @supabase/node-fetch

[liyachun01]

Chore

Describe the chore

Request update the static import of @supabase/node-fetch in src/lib/fetch.ts:

supabase-js/src/lib/fetch.ts

Lines 2 to 17 in 4c7f571

	import nodeFetch, { Headers as NodeFetchHeaders } from '@supabase/node-fetch'
	type Fetch = typeof fetch
	export const resolveFetch = (customFetch?: Fetch): Fetch => {
	let _fetch: Fetch
	if (customFetch) {
	_fetch = customFetch
	} else if (typeof fetch === 'undefined') {
	_fetch = nodeFetch as unknown as Fetch
	} else {
	_fetch = fetch
	}
	return (...args: Parameters<Fetch>) => _fetch(...args)
	}

supabase-js/src/lib/fetch.ts

Lines 18 to 24 in 4c7f571

	export const resolveHeadersConstructor = () => {
	if (typeof Headers === 'undefined') {
	return NodeFetchHeaders
	}
	return Headers
	}

Use dynamic import('@supabase/node-fetch') to avoid possible Cannot read property 'bind' of undefined error.

Additional context

Related to this issue supabase/postgrest-js#574.

Using @supabase/supabase-js, a user is able to provide custom fetch by providing a global.fetch option. However, with @supabase/node-fetch statically imported, a Cannot read property 'bind' of undefined error may throw at runtime.

TypeError: Cannot read property 'bind' of undefined
    at path/to/node_modules/@supabase/node-fetch/browser.js

The error is thrown when the runtime environment does not have native fetch on globalObject at all.

https://github.com/supabase/node-fetch/blob/bd8f50a4ae647e56cda296b8301d7dff01d4a87b/browser.js#L18.

/* @supabase/node-fetch/browser.js#L18 */
export default globalObject.fetch.bind(globalObject);

In some other @supabase/ packages like @supabase/auth-js, the fetch is resolved using a resolveFetch function:

https://github.com/supabase/auth-js/blob/8af88b6f4e41872b73e84c40f71793dab6c62126/src/lib/helpers.ts#L93-L104.

/* @supabase/auth-js/src/lib/helpers.ts#L93-L104. */
export const resolveFetch = (customFetch?: Fetch): Fetch => {
  let _fetch: Fetch
  if (customFetch) {
    _fetch = customFetch
  } else if (typeof fetch === 'undefined') {
    _fetch = (...args) =>
      import('@supabase/node-fetch' as any).then(({ default: fetch }) => fetch(...args))
  } else {
    _fetch = fetch
  }
  return (...args) => _fetch(...args)
}

This way, the node-fetch import is safe. We could also implement this for nodeFetch and Headers imported here.