Relay: Relay container suspends when not using `@defer` or `@module`.

[robrichard]

After updating to Relay v8, we started getting this error in a few places in our code. We are not using @defer or @module or any code from react-relay/hooks.

Relay Container for fragment `xyz` suspended. When using features such as @defer or @module, use `useFragment` instead of a Relay Container.

The underlying issue was that a component was being rendered while its data was missing from the store.

I traced it back to this condition: https://github.com/facebook/relay/blob/b931d0b1961cd04580d7f019ed3a0be9818f1ea6/packages/relay-runtime/store/RelayModernFragmentSpecResolver.js#L246

When the error occurs, isMissingData is true, but also getPromiseForRequestInFlight returns a promise, because sink.complete() was not yet called for the request.

It appears that this condition is checked synchronously after sink.next(value) here: https://github.com/facebook/relay/blob/b931d0b1961cd04580d7f019ed3a0be9818f1ea6/packages/relay-runtime/network/RelayObservable.js#L465-L466, but before sink.complete() is called on the next line.

Is this expected behavior? In Relay v7 the missing data would be handled gracefully.

[mattkrick]

this was causing some component flickering so we disabled it via a quick & dirty hack:

import RelayFeatureFlags from 'relay-runtime/lib/util/RelayFeatureFlags'
RelayFeatureFlags.ENABLE_RELAY_CONTAINERS_SUSPENSE = false

[sibelius]

this still happening on v9

[fuchien]

still happening here on v9, for now I am using @mattkrick solution!!

[jstejada]

thanks for reporting this and apologies for the delay, we'll change the default value of that flag, it should't be on by default