v0.3.8

internal/backend/agent/model/anthropic_test.go

@@ -0,0 +1,48 @@
+package modeladapter
+
+import (
+	"encoding/json"
+	"fmt"
+	"testing"
+)
+
+func TestAnthropicMessageCacheBreakpointsPreserveAppendOnlyHistory(t *testing.T) {
+	for size := 1; size <= 32; size++ {
+		t.Run(fmt.Sprintf("size_%02d", size), func(t *testing.T) {
+			previous := anthropicMessagesForAppendOnlyTest(size)
+			current := anthropicMessagesForAppendOnlyTest(size + 1)
+
+			applyAnthropicMessageCacheBreakpoints(previous)
+			applyAnthropicMessageCacheBreakpoints(current)
+
+			want := mustMarshalAnthropicMessagesForTest(t, previous)
+			got := mustMarshalAnthropicMessagesForTest(t, current[:len(previous)])
+			if got != want {
+				t.Fatalf("historical message prefix changed after append\nwant: %s\ngot:  %s", want, got)
+			}
+		})
+	}
+}
+
+func anthropicMessagesForAppendOnlyTest(count int) []anthropicMessage {
+	messages := make([]anthropicMessage, 0, count)
+	for index := 0; index < count; index++ {
+		messages = append(messages, anthropicMessage{
+			Role: "user",
+			Content: []map[string]any{{
+				"type": "text",
+				"text": fmt.Sprintf("message-%02d", index),
+			}},
+		})
+	}
+	return messages
+}
+
+func mustMarshalAnthropicMessagesForTest(t *testing.T, messages []anthropicMessage) string {
+	t.Helper()
+	payload, err := json.Marshal(messages)
+	if err != nil {
+		t.Fatalf("marshal anthropic messages: %v", err)
+	}
+	return string(payload)
+}