ollie/cmd/olliesrv/internal/agent/history_test.go

package agent

import (
	"testing"

	"ollie/cmd/olliesrv/internal/backend"
)

func TestBuildCompactedHistory_OrphanedToolWalkback(t *testing.T) {
	// Scenario: hotStart would land on a tool message. The walk-back logic
	// should include the preceding assistant message with tool_calls to avoid
	// violating the API constraint that tool messages must follow the assistant
	// message containing the corresponding tool_calls.

	// Build a history where the naive hotStart (total - hotTailSize) lands on a tool message.
	// hotTailSize = 6, so we need enough messages that slicing at -6 hits a tool message.

	// We want total - hotTailSize to land on a tool message.
	// hotTailSize = 6, so with 12 messages, hotStart = 6.
	// If messages[6] is a tool message, the walk-back should kick in.

	messages := []backend.Message{
		{Role: "user", Content: "old message 1"},
		{Role: "assistant", Content: "old response 1"},
		{Role: "user", Content: "old message 2"},
		{Role: "assistant", Content: "old response 2"},
		{Role: "user", Content: "request tool use"},
		{Role: "assistant", Content: "", ToolCalls: []backend.ToolCall{{ID: "tc1", Name: "shell"}}}, // index 5
		{Role: "tool", ToolCallID: "tc1", Content: "command output"},                                // index 6 - naive hotStart lands here!
		{Role: "user", Content: "next question"},
		{Role: "assistant", Content: "answer"},
		{Role: "user", Content: "another question"},
		{Role: "assistant", Content: "another answer"},
		{Role: "user", Content: "final question"},
	}

	// Total = 12, hotTailSize = 6, so naive hotStart = 6
	// messages[6] is a tool message → should walk back to 5.

	result := buildCompactedHistory("test summary", messages)

	// Result structure:
	// [0] cold zone (compaction summary)
	// [1] warm zone (if any)
	// [2+] hot zone

	// The hot zone should start with the assistant message at index 5, not the tool at 6.
	// Find the first non-summary message.

	var hotStart int
	for i, m := range result {
		if m.Role == "assistant" && len(m.ToolCalls) > 0 {
			hotStart = i
			break
		}
		if m.Role == "tool" {
			t.Errorf("hot zone starts with orphaned tool message at index %d", i)
			return
		}
	}

	// Verify the assistant with tool_calls is included before the tool message
	if hotStart == 0 {
		// The assistant message was not found, which is fine if the walk-back
		// moved the boundary correctly. Let's just verify no orphaned tool.
		for i, m := range result {
			if m.Role == "tool" {
				// Check that the previous message is assistant with matching tool_calls
				if i == 0 {
					t.Error("tool message at start of result with no preceding assistant")
					return
				}
				prev := result[i-1]
				if prev.Role != "assistant" {
					t.Errorf("tool message at %d not preceded by assistant (got %s)", i, prev.Role)
				}
			}
		}
	}
}

func TestBuildCompactedHistory_NoOrphanAtBoundary(t *testing.T) {
	// Simpler test: verify that any tool message in the result has
	// a preceding assistant message with tool_calls.

	messages := []backend.Message{
		{Role: "user", Content: "m1"},
		{Role: "assistant", Content: "r1"},
		{Role: "user", Content: "m2"},
		{Role: "assistant", Content: "", ToolCalls: []backend.ToolCall{{ID: "t1", Name: "shell"}, {ID: "t2", Name: "file_read"}}},
		{Role: "tool", ToolCallID: "t1", Content: "output1"},
		{Role: "tool", ToolCallID: "t2", Content: "output2"},
		{Role: "user", Content: "m3"},
		{Role: "assistant", Content: "r3"},
		{Role: "user", Content: "m4"},
		{Role: "assistant", Content: "r4"},
		{Role: "user", Content: "m5"},
		{Role: "assistant", Content: "r5"},
	}

	result := buildCompactedHistory("summary", messages)

	// Scan for tool messages and verify they have proper context
	for i, m := range result {
		if m.Role == "tool" {
			if i == 0 {
				t.Fatal("tool message at index 0 with no preceding message")
			}
			// Walk backward to find assistant with tool_calls
			found := false
			for j := i - 1; j >= 0; j-- {
				if result[j].Role == "assistant" && len(result[j].ToolCalls) > 0 {
					found = true
					break
				}
				if result[j].Role == "user" {
					// Hit a user message without finding assistant+tool_calls
					break
				}
			}
			if !found {
				t.Errorf("tool message at index %d has no preceding assistant with tool_calls", i)
			}
		}
	}
}