fix(streaming): add null usage fallback to all providers (#901)

Author: aimbit-ni

src/Providers/Anthropic/Handlers/Stream.php

@@ -268,7 +268,7 @@ protected function emitStreamEndEvent(): StreamEndEvent
             id: EventID::generate(),
             timestamp: time(),
             finishReason: $this->state->finishReason() ?? FinishReason::Stop,
-            usage: $this->state->usage(),
+            usage: $this->state->usage() ?? new Usage(0, 0),
             citations: $this->state->citations() !== [] ? $this->state->citations() : null,
             additionalContent: [
                 'thinking' => $this->state->thinkingSummaries() === [] ? null : implode('', $this->state->thinkingSummaries()),

src/Providers/DeepSeek/Handlers/Stream.php

@@ -242,7 +242,7 @@ protected function emitStreamEndEvent(): StreamEndEvent
             id: EventID::generate(),
             timestamp: time(),
             finishReason: $this->state->finishReason() ?? FinishReason::Stop,
-            usage: $this->state->usage()
+            usage: $this->state->usage() ?? new Usage(0, 0),
         );
     }
 

src/Providers/Gemini/Handlers/Stream.php

@@ -253,7 +253,7 @@ protected function emitStreamEndEvent(): StreamEndEvent
             id: EventID::generate(),
             timestamp: time(),
             finishReason: $this->state->finishReason() ?? FinishReason::Stop,
-            usage: $this->state->usage(),
+            usage: $this->state->usage() ?? new Usage(0, 0),
             additionalContent: Arr::whereNotNull([
                 'grounding_metadata' => $this->state->metadata()['grounding_metadata'] ?? null,
                 'thoughtSummaries' => $this->state->thinkingSummaries() === [] ? null : $this->state->thinkingSummaries(),

src/Providers/Groq/Handlers/Stream.php

@@ -199,7 +199,7 @@ protected function emitStreamEndEvent(): StreamEndEvent
             id: EventID::generate(),
             timestamp: time(),
             finishReason: $this->state->finishReason() ?? FinishReason::Stop,
-            usage: $this->state->usage()
+            usage: $this->state->usage() ?? new Usage(0, 0),
         );
     }
 

src/Providers/Mistral/Handlers/Stream.php

@@ -251,7 +251,7 @@ protected function emitStreamEndEvent(): StreamEndEvent
             id: EventID::generate(),
             timestamp: time(),
             finishReason: $this->state->finishReason() ?? FinishReason::Stop,
-            usage: $this->state->usage()
+            usage: $this->state->usage() ?? new Usage(0, 0),
         );
     }
 

src/Providers/OpenRouter/Handlers/Stream.php

@@ -257,7 +257,7 @@ protected function emitStreamEndEvent(): StreamEndEvent
             id: EventID::generate(),
             timestamp: time(),
             finishReason: $this->state->finishReason() ?? FinishReason::Stop,
-            usage: $this->state->usage()
+            usage: $this->state->usage() ?? new Usage(0, 0),
         );
     }
 

src/Providers/XAI/Handlers/Stream.php

@@ -227,7 +227,7 @@ protected function emitStreamEndEvent(): StreamEndEvent
             id: EventID::generate(),
             timestamp: time(),
             finishReason: $this->state->finishReason() ?? FinishReason::Stop,
-            usage: $this->state->usage()
+            usage: $this->state->usage() ?? new Usage(0, 0),
         );
     }