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Fixed OpenAI proxy streaming crash on single-chunk responses #138

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Merged
oleg68 merged 1 commit into from
May 23, 2026
Merged

Fixed OpenAI proxy streaming crash on single-chunk responses #138

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2 changes: 1 addition & 1 deletion pom.xml
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@

<groupId>io.github.nbplugins</groupId>
<artifactId>netbeans-plugin-claude-code-gui</artifactId>
<version>1.2.8-SNAPSHOT</version>
<version>1.2.9-SNAPSHOT</version>
<packaging>nbm</packaging>
<name>Netbeans Plugin Claude Code GUI</name>
<description>NetBeans plugin that provides a GUI for Claude Code CLI — run claude code sessions directly inside the IDE.</description>
Expand Down
152 changes: 98 additions & 54 deletions src/main/java/io/github/nbplugins/claudecodegui/openaiproxy/AnthropicToOpenAITranslator.java
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Original file line number Diff line number Diff line change
Expand Up @@ -71,7 +71,11 @@ public static ObjectNode translateRequest(JsonNode anthropicRequest) {

// stream
if (anthropicRequest.has("stream")) {
openai.put("stream", anthropicRequest.get("stream").asBoolean());
boolean stream = anthropicRequest.get("stream").asBoolean();
openai.put("stream", stream);
if (stream) {
openai.putObject("stream_options").put("include_usage", true);
}
}

// temperature, top_p (pass through if present)
Expand Down Expand Up @@ -422,6 +426,7 @@ static String mapFinishReason(String openaiReason) {
public static final class StreamingState {

private boolean messageStarted = false;
private boolean doneReceived = false;
private boolean thinkingBlockOpen = false;
private int thinkingBlockIndex = -1;
private boolean textBlockOpen = false;
Expand All @@ -443,6 +448,9 @@ private static final class ToolCallState {
int blockIndex;
}

public boolean isMessageStarted() { return messageStarted; }
public boolean isDoneReceived() { return doneReceived; }

/**
* Process one OpenAI SSE data line and return zero or more Anthropic SSE events.
*
Expand All @@ -451,6 +459,7 @@ private static final class ToolCallState {
*/
public String processChunk(String dataLine) {
if ("[DONE]".equals(dataLine)) {
doneReceived = true;
return buildDoneEvents();
}

Expand Down Expand Up @@ -582,99 +591,134 @@ public String processChunk(String dataLine) {
return out.toString();
}

private String buildDoneEvents() {
String buildDoneEvents() {
StringBuilder out = new StringBuilder();
if (thinkingBlockOpen) {
out.append(sseEvent("content_block_delta", buildSignatureDelta(thinkingBlockIndex)));
out.append(sseEvent("content_block_stop",
"{\"type\":\"content_block_stop\",\"index\":" + thinkingBlockIndex + "}"));
out.append(sseEvent("content_block_stop", blockStop(thinkingBlockIndex)));
}
if (textBlockOpen) {
out.append(sseEvent("content_block_stop",
"{\"type\":\"content_block_stop\",\"index\":" + textBlockIndex + "}"));
out.append(sseEvent("content_block_stop", blockStop(textBlockIndex)));
}
for (ToolCallState state : toolCalls.values()) {
if (state.started) {
out.append(sseEvent("content_block_stop",
"{\"type\":\"content_block_stop\",\"index\":" + state.blockIndex + "}"));
out.append(sseEvent("content_block_stop", blockStop(state.blockIndex)));
}
}
out.append(sseEvent("message_delta", buildMessageDelta()));
out.append(sseEvent("message_stop", "{\"type\":\"message_stop\"}"));
return out.toString();
}

private static String blockStop(int index) {
return "{\"type\":\"content_block_stop\",\"index\":" + index + "}";
}

private String buildMessageStart() {
return String.format(
"{\"type\":\"message_start\",\"message\":{\"id\":\"%s\",\"type\":\"message\"," +
"\"role\":\"assistant\",\"content\":[],\"model\":\"%s\"," +
"\"stop_reason\":null,\"stop_sequence\":null," +
"\"usage\":{\"input_tokens\":%d,\"output_tokens\":0}}}",
messageId, model, inputTokens);
try {
ObjectNode msg = MAPPER.createObjectNode();
msg.put("id", messageId);
msg.put("type", "message");
msg.put("role", "assistant");
msg.putArray("content");
msg.put("model", model);
msg.putNull("stop_reason");
msg.putNull("stop_sequence");
msg.putObject("usage")
.put("input_tokens", inputTokens)
.put("output_tokens", 0);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "message_start");
root.set("message", msg);
return MAPPER.writeValueAsString(root);
} catch (Exception e) {
return "{\"type\":\"message_start\",\"message\":{\"type\":\"message\"," +
"\"role\":\"assistant\",\"content\":[],\"stop_reason\":null," +
"\"stop_sequence\":null,\"usage\":{\"input_tokens\":0,\"output_tokens\":0}}}";
}
}

private static String buildTextBlockStart(int index) {
return String.format(
"{\"type\":\"content_block_start\",\"index\":%d," +
"\"content_block\":{\"type\":\"text\",\"text\":\"\"}}",
index);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "content_block_start");
root.put("index", index);
root.putObject("content_block").put("type", "text").put("text", "");
return toJson(root);
}

private static String buildTextDelta(int index, String text) {
String escaped = text.replace("\\", "\\\\").replace("\"", "\\\"")
.replace("\n", "\\n").replace("\r", "\\r")
.replace("\t", "\\t");
return String.format(
"{\"type\":\"content_block_delta\",\"index\":%d," +
"\"delta\":{\"type\":\"text_delta\",\"text\":\"%s\"}}",
index, escaped);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "content_block_delta");
root.put("index", index);
root.putObject("delta").put("type", "text_delta").put("text", text);
return toJson(root);
}

private static String buildToolUseBlockStart(int index, String id, String name) {
return String.format(
"{\"type\":\"content_block_start\",\"index\":%d," +
"\"content_block\":{\"type\":\"tool_use\",\"id\":\"%s\",\"name\":\"%s\",\"input\":{}}}",
index, id, name);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "content_block_start");
root.put("index", index);
ObjectNode cb = root.putObject("content_block");
cb.put("type", "tool_use");
cb.put("id", id);
cb.put("name", name);
cb.putObject("input");
return toJson(root);
}

private static String buildInputJsonDelta(int index, String partialJson) {
String escaped = partialJson.replace("\\", "\\\\").replace("\"", "\\\"")
.replace("\n", "\\n").replace("\r", "\\r");
return String.format(
"{\"type\":\"content_block_delta\",\"index\":%d," +
"\"delta\":{\"type\":\"input_json_delta\",\"partial_json\":\"%s\"}}",
index, escaped);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "content_block_delta");
root.put("index", index);
root.putObject("delta").put("type", "input_json_delta").put("partial_json", partialJson);
return toJson(root);
}

private static String buildThinkingBlockStart(int index) {
return String.format(
"{\"type\":\"content_block_start\",\"index\":%d," +
"\"content_block\":{\"type\":\"thinking\",\"thinking\":\"\"}}",
index);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "content_block_start");
root.put("index", index);
root.putObject("content_block").put("type", "thinking").put("thinking", "");
return toJson(root);
}

private static String buildThinkingDelta(int index, String thinking) {
String escaped = thinking.replace("\\", "\\\\").replace("\"", "\\\"")
.replace("\n", "\\n").replace("\r", "\\r")
.replace("\t", "\\t");
return String.format(
"{\"type\":\"content_block_delta\",\"index\":%d," +
"\"delta\":{\"type\":\"thinking_delta\",\"thinking\":\"%s\"}}",
index, escaped);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "content_block_delta");
root.put("index", index);
root.putObject("delta").put("type", "thinking_delta").put("thinking", thinking);
return toJson(root);
}

private static String buildSignatureDelta(int index) {
return String.format(
"{\"type\":\"content_block_delta\",\"index\":%d," +
"\"delta\":{\"type\":\"signature_delta\",\"signature\":\"proxy_thinking_sig\"}}",
index);
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "content_block_delta");
root.put("index", index);
root.putObject("delta").put("type", "signature_delta").put("signature", "proxy_thinking_sig");
return toJson(root);
}

private String buildMessageDelta() {
return String.format(
"{\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"%s\"," +
"\"stop_sequence\":null},\"usage\":{\"output_tokens\":%d}}",
stopReason, outputTokens);
try {
ObjectNode root = MAPPER.createObjectNode();
root.put("type", "message_delta");
ObjectNode delta = root.putObject("delta");
delta.put("stop_reason", stopReason);
delta.putNull("stop_sequence");
root.putObject("usage").put("output_tokens", outputTokens);
return MAPPER.writeValueAsString(root);
} catch (Exception e) {
return "{\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"end_turn\"," +
"\"stop_sequence\":null},\"usage\":{\"output_tokens\":0}}";
}
}

private static String toJson(ObjectNode node) {
try {
return MAPPER.writeValueAsString(node);
} catch (Exception e) {
return "{}";
}
}
}

Expand Down
4 changes: 4 additions & 0 deletions src/main/java/io/github/nbplugins/claudecodegui/openaiproxy/OpenAIProxyServlet.java
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Original file line number Diff line number Diff line change
Expand Up @@ -231,6 +231,10 @@ private void handleStreaming(HttpClient httpClient, HttpRequest httpReq, String
}
}

if (state.isMessageStarted() && !state.isDoneReceived()) {
writer.write(state.buildDoneEvents());
}

if (debug) {
LOG.info("OpenAI proxy: streaming done, total chunks=" + chunkCount);
}
Expand Down
106 changes: 106 additions & 0 deletions ...t/java/io/github/nbplugins/claudecodegui/openaiproxy/AnthropicToOpenAITranslatorTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -274,4 +274,110 @@ void sseEvent_format() {
String event = AnthropicToOpenAITranslator.sseEvent("ping", "{\"type\":\"ping\"}");
assertEquals("event: ping\ndata: {\"type\":\"ping\"}\n\n", event);
}

// -------------------------------------------------------------------------
// Control character escaping regression tests (fix: use Jackson instead of manual escaping)
// -------------------------------------------------------------------------

@Test
void streaming_textWithFormFeedProducesValidJson() throws Exception {
var s = state();
s.processChunk("{\"id\":\"c1\",\"model\":\"m\",\"choices\":[{\"delta\":{\"role\":\"assistant\"},\"index\":0}]}");

String textWithControlChars = "line1\fline2line3line4";
String chunk = s.processChunk(
"{\"id\":\"c1\",\"choices\":[{\"delta\":{\"content\":" +
AnthropicToOpenAITranslator.MAPPER.writeValueAsString(textWithControlChars) +
"},\"index\":0}]}");

// The SSE data line must be valid JSON
String dataLine = extractSseDataLine(chunk, "content_block_delta");
assertNotNull(dataLine, "Expected content_block_delta event in: " + chunk);
JsonNode parsed = AnthropicToOpenAITranslator.MAPPER.readTree(dataLine);
assertEquals(textWithControlChars, parsed.path("delta").path("text").asText());
}

@Test
void streaming_thinkingWithControlCharsProducesValidJson() throws Exception {
var s = state();
s.processChunk("{\"id\":\"c1\",\"model\":\"m\",\"choices\":[{\"delta\":{\"role\":\"assistant\"},\"index\":0}]}");

String thinkingWithCtrl = "thinking\n\tcode:";
String chunk = s.processChunk(
"{\"id\":\"c1\",\"choices\":[{\"delta\":{\"reasoning_content\":" +
AnthropicToOpenAITranslator.MAPPER.writeValueAsString(thinkingWithCtrl) +
"},\"index\":0}]}");

String dataLine = extractSseDataLine(chunk, "content_block_delta");
assertNotNull(dataLine, "Expected content_block_delta event in: " + chunk);
JsonNode parsed = AnthropicToOpenAITranslator.MAPPER.readTree(dataLine);
assertEquals(thinkingWithCtrl, parsed.path("delta").path("thinking").asText());
}

@Test
void streaming_singleChunkFullResponseProducesCompleteStream() throws Exception {
var s = state();

// Single-chunk pseudo-streaming: full response + finish_reason in one chunk
String single = s.processChunk(
"{\"id\":\"c1\",\"model\":\"deepseek\",\"choices\":[{\"delta\":{" +
"\"role\":\"assistant\",\"content\":\"Hello world\"},\"finish_reason\":\"stop\",\"index\":0}]," +
"\"usage\":{\"prompt_tokens\":10,\"completion_tokens\":3}}");

assertTrue(single.contains("message_start"), "missing message_start: " + single);
assertTrue(single.contains("content_block_start"), "missing content_block_start: " + single);
assertTrue(single.contains("text_delta"), "missing text_delta: " + single);

String done = s.processChunk("[DONE]");
assertTrue(done.contains("content_block_stop"), "missing content_block_stop: " + done);
assertTrue(done.contains("message_delta"), "missing message_delta: " + done);
assertTrue(done.contains("message_stop"), "missing message_stop: " + done);
assertTrue(done.contains("end_turn"), "missing end_turn: " + done);
// Usage from the chunk should be in message_delta
JsonNode msgDelta = AnthropicToOpenAITranslator.MAPPER.readTree(
extractSseDataLine(done, "message_delta"));
assertEquals(3, msgDelta.path("usage").path("output_tokens").asInt());
}

@Test
void translateRequest_streamOptionsAddedWhenStreamTrue() throws Exception {
ObjectNode result = AnthropicToOpenAITranslator.translateRequest(load("req_simple_text.json"));
// req_simple_text.json has no stream field; stream_options should not be added
assertFalse(result.has("stream_options"), "stream_options must not appear for non-streaming");
}

@Test
void translateRequest_streamOptionsAddedForStreamingRequest() throws Exception {
ObjectNode req = (ObjectNode) load("req_simple_text.json");
req.put("stream", true);
ObjectNode result = AnthropicToOpenAITranslator.translateRequest(req);
assertTrue(result.has("stream_options"), "stream_options missing");
assertTrue(result.path("stream_options").path("include_usage").asBoolean(), "include_usage not true");
}

@Test
void streaming_missingDoneHandledByIsMessageStartedAndIsDoneReceived() {
var s = state();
assertFalse(s.isMessageStarted());
assertFalse(s.isDoneReceived());

s.processChunk("{\"id\":\"c1\",\"model\":\"m\",\"choices\":[{\"delta\":{\"content\":\"hi\"},\"index\":0}]}");
assertTrue(s.isMessageStarted());
assertFalse(s.isDoneReceived());

s.processChunk("[DONE]");
assertTrue(s.isDoneReceived());
}

/** Extract the JSON data line for the first SSE event with the given name from an event block string. */
private static String extractSseDataLine(String events, String eventName) {
for (String block : events.split("\n\n")) {
if (block.contains("event: " + eventName)) {
for (String line : block.split("\n")) {
if (line.startsWith("data: ")) return line.substring(6);
}
}
}
return null;
}
}
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