Fix exception parsing the first part; handle error code (#365)

src/test/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/stream/JsonRpcStreamParserTest.kt

@@ -1,5 +1,7 @@
 package io.emeraldpay.dshackle.upstream.rpcclient.stream
 
+import org.junit.jupiter.api.Assertions.assertArrayEquals
+import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Assertions.assertNotNull
 import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test
@@ -25,6 +27,31 @@ class JsonRpcStreamParserTest {
             .verify(Duration.ofSeconds(1))
     }
 
+    @Test
+    fun `if non 200 response code then aggregate response`() {
+        val statusCode = 403
+        val bytes = "{\"strangeResponse\": 2}".toByteArray()
+        val stream: Flux<ByteArray> = Flux.just(bytes)
+
+        val response = streamParser.streamParse(statusCode, stream).block() as AggregateResponse
+
+        assertEquals(statusCode, response.code)
+        assertArrayEquals(bytes, response.response)
+    }
+
+    @Test
+    fun `if exception is thrown during parse first part then aggregate response`() {
+        val statusCode = 200
+        val bytes = "{\"jsonrpc\":".toByteArray()
+        val secondBytes = "2, \"end\": 2}".toByteArray()
+        val stream: Flux<ByteArray> = Flux.just(bytes, secondBytes)
+
+        val response = streamParser.streamParse(statusCode, stream).block() as AggregateResponse
+
+        assertEquals(statusCode, response.code)
+        assertArrayEquals(bytes.plus(secondBytes), response.response)
+    }
+
     @ParameterizedTest
     @MethodSource("data")
     fun `if first part has result field then single response`(