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fix(chat): guard null check operators to prevent crash on uninitialized chat #33

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Merged
using-system merged 2 commits into from
Apr 21, 2026
Merged

fix(chat): guard null check operators to prevent crash on uninitialized chat #33

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6793d7c
fix(chat): guard null check operators to prevent crash on uninitializ…
using-system Apr 21, 2026
54568d5
fix(chat): address review feedback on null guard consistency
using-system Apr 21, 2026
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46 changes: 32 additions & 14 deletions lib/features/chat/presentation/conversation_page.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -220,15 +220,22 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
}
}

final chat = _chat;
if (chat == null) {
if (mounted) {
setState(() => _chatError = 'Model initialization failed');
}
return;
}

if (mounted) {
setState(() => _chatError = null);
}

final repo = await ref.read(chatRepositoryProvider.future);
final messages = await repo.getMessages(widget.conversationId);
for (final msg in messages) {
if (msg.content.isEmpty) continue;
await _chat!.addQueryChunk(
await chat.addQueryChunk(
gemma.Message.text(text: msg.content, isUser: msg.role == 'user'),
);
// Yield to the UI between history messages to keep input responsive.
Expand Down Expand Up @@ -290,7 +297,9 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
onError: (e, s) => debugPrint('Persist failed: $e\n$s'),
);

await _chat!.addQueryChunk(gemma.Message.text(text: text, isUser: true));
final chat = _chat;
if (chat == null) return;
await chat.addQueryChunk(gemma.Message.text(text: text, isUser: true));

await _streamAiResponse();
} catch (e, stack) {
Expand All @@ -303,7 +312,8 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
}

Future<void> _doSendAudioWithText(String text) async {
final audioPath = _pendingAudioPath!;
final audioPath = _pendingAudioPath;
if (audioPath == null) return;

try {
final audioBytes = await File(audioPath).readAsBytes();
Expand Down Expand Up @@ -336,7 +346,9 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {

final prompt = text.trim().isNotEmpty ? text.trim() : l10n.chatAudioPrompt;

await _chat!.addQueryChunk(
final chat = _chat;
if (chat == null) return;
await chat.addQueryChunk(
gemma.Message.withAudio(
text: prompt,
audioBytes: audioBytes,
Expand Down Expand Up @@ -380,7 +392,8 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
}

Future<void> _doSendImageWithText(String text) async {
final imagePath = _pendingImagePath!;
final imagePath = _pendingImagePath;
if (imagePath == null) return;

try {
final imageBytes = await File(imagePath).readAsBytes();
Expand Down Expand Up @@ -414,7 +427,9 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
final prompt = text.trim().isNotEmpty ? text.trim() : l10n.chatImagePrompt;

// Send to InferenceChat with image.
await _chat!.addQueryChunk(
final chat = _chat;
if (chat == null) return;
await chat.addQueryChunk(
gemma.Message.withImage(
text: prompt,
imageBytes: imageBytes,
Expand Down Expand Up @@ -474,6 +489,9 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
}

Future<void> _streamAiResponse() async {
final chat = _chat;
if (chat == null) return;

final streamId = _uuid.v4();
final streamMsgId = _uuid.v4();
final now = DateTime.now();
Expand All @@ -500,7 +518,7 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
bool _hadToolCall = false;

try {
await for (final response in _chat!.generateChatResponseAsync()) {
await for (final response in chat.generateChatResponseAsync()) {
if (!mounted) break;

if (response is ThinkingResponse) {
Expand Down Expand Up @@ -571,9 +589,9 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
if (mounted) {
final toolReg = ref.read(toolRegistryProvider);
final toolResult = await toolReg.handle(response, context);
if (toolResult != null && _chat != null) {
if (toolResult != null && _chat == chat) {
_hadToolCall = true;
await _chat!.addQueryChunk(gemma.Message.toolResponse(
await chat.addQueryChunk(gemma.Message.toolResponse(
toolName: toolResult.name,
response: toolResult.result,
));
Comment thread
using-system marked this conversation as resolved.
Expand All @@ -584,9 +602,9 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {
final toolReg = ref.read(toolRegistryProvider);
for (final call in response.calls) {
final toolResult = await toolReg.handle(call, context);
if (toolResult != null && _chat != null) {
if (toolResult != null && _chat == chat) {
_hadToolCall = true;
await _chat!.addQueryChunk(gemma.Message.toolResponse(
await chat.addQueryChunk(gemma.Message.toolResponse(
toolName: toolResult.name,
response: toolResult.result,
));
Comment thread
using-system marked this conversation as resolved.
Expand All @@ -597,10 +615,10 @@ class _ConversationPageState extends ConsumerState<ConversationPage> {

// After stream ends, if a tool was called, re-generate so the LLM
// produces its final answer using the tool results as context.
if (_hadToolCall && mounted && _chat != null) {
if (_hadToolCall && mounted && _chat == chat) {
debugPrint('>>> Re-generating after tool call...');
int tokenCount = 0;
await for (final response in _chat!.generateChatResponseAsync()) {
await for (final response in chat.generateChatResponseAsync()) {
if (!mounted) break;
debugPrint('>>> Re-gen response: ${response.runtimeType}');
if (response is TextResponse) {
Expand Down