Don't use WebSockets on watchOS

Author: simolus3

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.11.2 (unreleased)
+
+- Don't attempt to create WebSocket connections on watchOS.
+
 ## 1.11.1
 
 - Fix RSocket connection bugs on iOS (and other platforms using the RSocket sync transport):

common/src/commonJava/kotlin/com/powersync/internal/PlatformSpecificQuirks.commonJava.kt

@@ -0,0 +1,3 @@
+package com.powersync.internal
+
+internal actual fun platformAllowsWebSockets(): Boolean = true

common/src/commonMain/kotlin/com/powersync/internal/PlatformSpecificQuirks.kt

@@ -20,8 +20,15 @@ import kotlin.concurrent.atomics.ExperimentalAtomicApi
 public val httpClientIsKnownToNotSupportBackpressure: AtomicReference<((HttpClientEngineConfig) -> Boolean)?> = AtomicReference(null)
 
 @OptIn(ExperimentalAtomicApi::class, InternalPowerSyncAPI::class)
-internal val HttpClientEngineConfig.isKnownToNotSupportBackpressure: Boolean
+internal val HttpClientEngineConfig.shouldUseRSocketStream: Boolean
     get() {
+        if (!platformAllowsWebSockets()) {
+            // We can only use regular HTTP on watchOS, so avoid falling back to RSocket streams there.
+            return false
+        }
+
         val check = httpClientIsKnownToNotSupportBackpressure.load() ?: return false
         return check(this)
     }
+
+internal expect fun platformAllowsWebSockets(): Boolean

common/src/commonMain/kotlin/com/powersync/sync/ConfigureSyncHttpClient.kt

@@ -1,7 +1,7 @@
 package com.powersync.sync
 
 import com.powersync.ExperimentalPowerSyncAPI
-import com.powersync.internal.isKnownToNotSupportBackpressure
+import com.powersync.internal.shouldUseRSocketStream
 import com.powersync.sync.StreamingSyncClient.Companion.SOCKET_TIMEOUT
 import io.ktor.client.HttpClient
 import io.ktor.client.HttpClientConfig
@@ -71,7 +71,7 @@ internal object WebSocketIfNecessaryPlugin : HttpClientPlugin<Unit, WebSockets>
         plugin: WebSockets,
         scope: HttpClient,
     ) {
-        if (scope.engineConfig.isKnownToNotSupportBackpressure) {
+        if (scope.engineConfig.shouldUseRSocketStream) {
             WebSockets.install(plugin, scope)
             scope.attributes.put(needsRSocketKey, true)
         } else {

common/src/nativeMain/kotlin/com/powersync/internal/PlatformSpecificQuirks.native.kt

@@ -0,0 +1,6 @@
+package com.powersync.internal
+
+import kotlin.experimental.ExperimentalNativeApi
+
+@OptIn(ExperimentalNativeApi::class)
+internal actual fun platformAllowsWebSockets(): Boolean = Platform.osFamily != OsFamily.WATCHOS