Fork tasks from snapshots; snapshot only when text follows tool calls

internal/agents/fork_internal_test.go

@@ -0,0 +1,49 @@
+package agents
+
+import (
+	"testing"
+
+	"g.fc.run/misc/byre/internal/api"
+)
+
+func TestForkPoint(t *testing.T) {
+	s1, s2 := "s1", "s2"
+	ev := func(seq int64, sess *string, kind string, payload map[string]any) api.Event {
+		return api.Event{Seq: seq, AgentSessionId: sess, Kind: kind, Payload: payload}
+	}
+	events := []api.Event{
+		ev(1, &s1, "user.message", map[string]any{"text": "go"}),
+		ev(2, &s1, "agent.message", map[string]any{"text": "on it", "vendor_uuid": "u-msg"}),
+		ev(3, &s1, "agent.tool_call", map[string]any{"id": "a", "vendor_uuid": "u-call-a"}),
+		ev(4, &s1, "agent.tool_call", map[string]any{"id": "b", "vendor_uuid": "u-call-b"}),
+		ev(5, &s1, "agent.tool_call", map[string]any{"id": "x", "parent_tool_use_id": "b"}),
+		ev(6, nil, "snapshot.created", map[string]any{"n": 1}),
+		ev(7, &s1, "agent.tool_result", map[string]any{"tool_use_id": "a", "vendor_uuid": "u-res-a"}),
+		ev(8, &s2, "agent.tool_result", map[string]any{"tool_use_id": "b", "vendor_uuid": "u-other"}),
+		ev(9, &s1, "agent.tool_result", map[string]any{"tool_use_id": "b", "vendor_uuid": "u-res-b"}),
+		ev(10, &s1, "agent.message", map[string]any{"text": "done", "vendor_uuid": "u-done"}),
+		ev(11, &s1, "turn.ended", map[string]any{}),
+		ev(12, &s1, "user.message", map[string]any{"text": "more"}),
+		ev(13, &s1, "agent.tool_call", map[string]any{"id": "c", "vendor_uuid": "u-call-c"}),
+		ev(14, &s1, "agent.tool_result", map[string]any{"tool_use_id": "c", "vendor_uuid": "u-res-c"}),
+	}
+
+	for _, c := range []struct {
+		seq  int64
+		want string
+	}{
+		{1, ""},
+		{2, "u-msg"},
+		{3, "u-res-b"},
+		{5, "u-res-b"},
+		{9, "u-res-b"},
+		{11, "u-done"},
+		{12, "u-done"},
+		{13, "u-res-c"},
+	} {
+		got := forkPoint(events, s1, c.seq)
+		if got != c.want {
+			t.Errorf("forkPoint at seq %d = %q, want %q", c.seq, got, c.want)
+		}
+	}
+}