fix(client): disallow reusing stream response

chore: unknown commit message

openai-java-core/src/main/kotlin/com/openai/core/handlers/SseHandler.kt

@@ -20,44 +20,50 @@ internal fun sseHandler(jsonMapper: JsonMapper): Handler<StreamResponse<SseMessa
 
         override fun handle(response: HttpResponse): StreamResponse<SseMessage> {
             val reader = response.body().bufferedReader()
-            val sequence = sequence {
-                reader.useLines { lines ->
-                    val state = SseState(jsonMapper)
-                    var done = false
-                    for (line in lines) {
-                        // Stop emitting messages, but iterate through the full stream.
-                        if (done) {
-                            continue
-                        }
-                        val message = state.decode(line) ?: continue
-
-                        if (message.data.startsWith("[DONE]")) {
-                            // In this case we don't break because we still want to iterate through
-                            // the full stream.
-                            done = true
-                            continue
-                        }
-
-                        if (message.event == null) {
-                            val error =
-                                message.json<JsonValue>().asObject().getOrNull()?.get("error")
-                            if (error != null) {
-                                val errorMessage =
-                                    error.asString().getOrNull()
-                                        ?: error
+            val sequence =
+                sequence {
+                        reader.useLines { lines ->
+                            val state = SseState(jsonMapper)
+                            var done = false
+                            for (line in lines) {
+                                // Stop emitting messages, but iterate through the full stream.
+                                if (done) {
+                                    continue
+                                }
+                                val message = state.decode(line) ?: continue
+
+                                if (message.data.startsWith("[DONE]")) {
+                                    // In this case we don't break because we still want to iterate
+                                    // through the full stream.
+                                    done = true
+                                    continue
+                                }
+
+                                if (message.event == null) {
+                                    val error =
+                                        message
+                                            .json<JsonValue>()
                                             .asObject()
                                             .getOrNull()
-                                            ?.get("message")
-                                            ?.asString()
-                                            ?.getOrNull()
-                                        ?: "An error occurred during streaming"
-                                throw OpenAIException(errorMessage)
+                                            ?.get("error")
+                                    if (error != null) {
+                                        val errorMessage =
+                                            error.asString().getOrNull()
+                                                ?: error
+                                                    .asObject()
+                                                    .getOrNull()
+                                                    ?.get("message")
+                                                    ?.asString()
+                                                    ?.getOrNull()
+                                                ?: "An error occurred during streaming"
+                                        throw OpenAIException(errorMessage)
+                                    }
+                                    yield(message)
+                                }
                             }
-                            yield(message)
                         }
                     }
-                }
-            }
+                    .constrainOnce()
 
             return PhantomReachableClosingStreamResponse(
                 object : StreamResponse<SseMessage> {

openai-java-core/src/test/kotlin/com/openai/core/handlers/SseHandlerTest.kt

@@ -10,6 +10,8 @@ import java.io.InputStream
 import java.nio.charset.StandardCharsets
 import java.util.stream.Collectors.toList
 import org.assertj.core.api.Assertions.assertThat
+import org.assertj.core.api.Assertions.catchThrowable
+import org.junit.jupiter.api.Test
 import org.junit.jupiter.params.ParameterizedTest
 import org.junit.jupiter.params.provider.EnumSource
 
@@ -105,17 +107,7 @@ class SseHandlerTest {
     @ParameterizedTest
     @EnumSource
     fun handle(testCase: TestCase) {
-        val response =
-            object : HttpResponse {
-                override fun statusCode(): Int = 0
-
-                override fun headers(): Headers = Headers.builder().build()
-
-                override fun body(): InputStream =
-                    ByteArrayInputStream(testCase.body.toByteArray(StandardCharsets.UTF_8))
-
-                override fun close() {}
-            }
+        val response = httpResponse(testCase.body)
         var messages: List<SseMessage>? = null
         var exception: Exception? = null
 
@@ -134,6 +126,32 @@ class SseHandlerTest {
             assertThat(exception).hasMessage(testCase.expectedException.message)
         }
     }
+
+    @Test
+    fun cannotReuseStream() {
+        val response = httpResponse("body")
+        val streamResponse = sseHandler(jsonMapper()).handle(response)
+
+        val throwable =
+            streamResponse.use {
+                it.stream().collect(toList())
+                catchThrowable { it.stream().collect(toList()) }
+            }
+
+        assertThat(throwable).isInstanceOf(IllegalStateException::class.java)
+    }
 }
 
+private fun httpResponse(body: String): HttpResponse =
+    object : HttpResponse {
+        override fun statusCode(): Int = 0
+
+        override fun headers(): Headers = Headers.builder().build()
+
+        override fun body(): InputStream =
+            ByteArrayInputStream(body.toByteArray(StandardCharsets.UTF_8))
+
+        override fun close() {}
+    }
+
 private fun sseMessageBuilder() = SseMessage.builder().jsonMapper(jsonMapper())