Files
goclaw/internal/agent/loop_history_test.go
T
viettranx 48335d7797 feat(pruning)!: faithful port of TS context pruning + backfill migration
Port goclaw context pruning to match upstream TS design in
openclaw/src/agents/pi-hooks/context-pruning/:

- Opt-in default: prune only when mode="cache-ttl" (was opt-out)
- Remove Pass 0 per-result 30% guard (duplicated Pass 1 with different
  suffix, caused wobble)
- Dedupe double prune call per iteration: PruneStage owns the single
  entry point; loop_history only runs limitHistoryTurns + sanitizeHistory
- Add cache-TTL gate for Anthropic prompt cache: skip prune while cache
  is live, scoped per-session via sync.Map
- Add context.pruned event emission for observability
- Configurable TTL as Go duration string ("5m", "30s")

BREAKING CHANGE: context pruning now opt-in. Add
contextPruning.mode: "cache-ttl" to config.agents.defaults to restore.

Migration 51 / SQLite v19 backfills mode="cache-ttl" for agents with
existing custom context_pruning config missing the mode field, so
previously-configured agents keep pruning after the opt-in flip.
NULL configs stay NULL (new opt-in default applies).

Web UI adds Cache TTL input + toggle wiring mode to cache-ttl/off.
2026-04-15 11:24:57 +07:00

674 lines
20 KiB
Go

package agent
import (
"strings"
"testing"
"github.com/nextlevelbuilder/goclaw/internal/config"
"github.com/nextlevelbuilder/goclaw/internal/providers"
)
func TestLimitHistoryTurns_NoLimit(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "m1"},
{Role: "assistant", Content: "r1"},
{Role: "user", Content: "m2"},
{Role: "assistant", Content: "r2"},
}
got := limitHistoryTurns(msgs, 0)
if len(got) != 4 {
t.Errorf("expected 4 messages, got %d", len(got))
}
}
func TestLimitHistoryTurns_KeepLast2(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "m1"},
{Role: "assistant", Content: "r1"},
{Role: "user", Content: "m2"},
{Role: "assistant", Content: "r2"},
{Role: "user", Content: "m3"},
{Role: "assistant", Content: "r3"},
}
got := limitHistoryTurns(msgs, 2)
if len(got) != 4 {
t.Fatalf("expected 4 messages, got %d", len(got))
}
if got[0].Content != "m2" {
t.Errorf("expected m2, got %s", got[0].Content)
}
}
func TestLimitHistoryTurns_KeepLast1(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "m1"},
{Role: "assistant", Content: "r1"},
{Role: "user", Content: "m2"},
{Role: "assistant", Content: "r2"},
}
got := limitHistoryTurns(msgs, 1)
if len(got) != 2 {
t.Fatalf("expected 2 messages, got %d", len(got))
}
if got[0].Content != "m2" {
t.Errorf("expected m2, got %s", got[0].Content)
}
}
func TestLimitHistoryTurns_WithToolMessages(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "m1"},
{Role: "assistant", Content: "r1", ToolCalls: []providers.ToolCall{{ID: "tc1", Name: "read_file"}}},
{Role: "tool", Content: "result1", ToolCallID: "tc1"},
{Role: "assistant", Content: "final1"},
{Role: "user", Content: "m2"},
{Role: "assistant", Content: "r2"},
}
got := limitHistoryTurns(msgs, 1)
if len(got) != 2 {
t.Fatalf("expected 2 messages (last turn), got %d", len(got))
}
if got[0].Content != "m2" {
t.Errorf("expected m2, got %s", got[0].Content)
}
}
func TestLimitHistoryTurns_Empty(t *testing.T) {
got := limitHistoryTurns(nil, 5)
if len(got) != 0 {
t.Errorf("expected empty, got %d", len(got))
}
}
func TestLimitHistoryTurns_LimitExceedsTotal(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "m1"},
{Role: "assistant", Content: "r1"},
}
got := limitHistoryTurns(msgs, 100)
if len(got) != 2 {
t.Errorf("expected 2, got %d", len(got))
}
}
func TestSanitizeHistory_Empty(t *testing.T) {
got, _ := sanitizeHistory(nil)
if len(got) != 0 {
t.Errorf("expected empty, got %d", len(got))
}
}
func TestSanitizeHistory_DropsLeadingOrphanedTools(t *testing.T) {
msgs := []providers.Message{
{Role: "tool", Content: "orphan1", ToolCallID: "tc1"},
{Role: "tool", Content: "orphan2", ToolCallID: "tc2"},
{Role: "user", Content: "hello"},
{Role: "assistant", Content: "hi"},
}
got, _ := sanitizeHistory(msgs)
if len(got) != 2 {
t.Fatalf("expected 2 messages, got %d", len(got))
}
if got[0].Role != "user" {
t.Errorf("expected user, got %s", got[0].Role)
}
}
func TestSanitizeHistory_MatchesToolResults(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "do something"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "tc1", Name: "read_file"},
{ID: "tc2", Name: "write_file"},
}},
{Role: "tool", Content: "file data", ToolCallID: "tc1"},
{Role: "tool", Content: "written", ToolCallID: "tc2"},
{Role: "assistant", Content: "done"},
}
got, _ := sanitizeHistory(msgs)
if len(got) != 5 {
t.Fatalf("expected 5, got %d", len(got))
}
}
func TestSanitizeHistory_SynthesizesMissingToolResult(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "do something"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "tc1", Name: "read_file"},
{ID: "tc2", Name: "write_file"},
}},
{Role: "tool", Content: "file data", ToolCallID: "tc1"},
// tc2 is missing
{Role: "user", Content: "next"},
}
got, _ := sanitizeHistory(msgs)
// user + assistant + tc1 result + synthesized tc2 result + user
if len(got) != 5 {
t.Fatalf("expected 5, got %d", len(got))
}
// The synthesized message should be for tc2
foundSynthesized := false
for _, m := range got {
if m.ToolCallID == "tc2" && m.Role == "tool" {
foundSynthesized = true
if m.Content != "[Tool result missing — session was compacted]" {
t.Errorf("unexpected synthesized content: %s", m.Content)
}
}
}
if !foundSynthesized {
t.Error("missing synthesized tool result for tc2")
}
}
func TestSanitizeHistory_DropsMismatchedToolResult(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "hello"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "tc1", Name: "read_file"},
}},
{Role: "tool", Content: "ok", ToolCallID: "tc1"},
{Role: "tool", Content: "stray", ToolCallID: "unknown_id"},
{Role: "user", Content: "next"},
}
got, _ := sanitizeHistory(msgs)
// The stray tool message should be dropped, tc1 result kept
for _, m := range got {
if m.ToolCallID == "unknown_id" {
t.Error("mismatched tool result should be dropped")
}
}
}
func TestSanitizeHistory_DropsOrphanedToolMidHistory(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "hello"},
{Role: "assistant", Content: "hi"},
{Role: "tool", Content: "orphan mid", ToolCallID: "tc_orphan"},
{Role: "user", Content: "bye"},
}
got, _ := sanitizeHistory(msgs)
for _, m := range got {
if m.ToolCallID == "tc_orphan" {
t.Error("orphaned mid-history tool should be dropped")
}
}
if len(got) != 3 {
t.Errorf("expected 3, got %d", len(got))
}
}
func TestSanitizeHistory_DedupsDuplicateIDsAcrossTurns(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "turn 1"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "call_abc", Name: "read_file"},
}},
{Role: "tool", Content: "result1", ToolCallID: "call_abc"},
{Role: "user", Content: "turn 2"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "call_abc", Name: "write_file"}, // duplicate ID from earlier turn
}},
{Role: "tool", Content: "result2", ToolCallID: "call_abc"},
{Role: "assistant", Content: "done"},
}
got, _ := sanitizeHistory(msgs)
// Collect all tool call IDs (from assistant messages)
seen := make(map[string]bool)
for _, m := range got {
for _, tc := range m.ToolCalls {
if seen[tc.ID] {
t.Errorf("duplicate tool call ID in sanitized output: %s", tc.ID)
}
seen[tc.ID] = true
}
}
// Both tool results should be present (paired correctly)
toolResults := 0
for _, m := range got {
if m.Role == "tool" {
toolResults++
}
}
if toolResults != 2 {
t.Errorf("expected 2 tool results, got %d", toolResults)
}
}
func TestSanitizeHistory_DedupsDuplicateIDsWithinTurn(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "do two things"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "call_abc", Name: "read_file"},
{ID: "call_abc", Name: "write_file"}, // same ID within turn
}},
{Role: "tool", Content: "result1", ToolCallID: "call_abc"},
{Role: "tool", Content: "result2", ToolCallID: "call_abc"},
{Role: "assistant", Content: "done"},
}
got, dropped := sanitizeHistory(msgs)
if dropped != 1 {
t.Errorf("expected 1 dropped (dedup counts as change), got %d", dropped)
}
// Both tool results must be present and paired correctly
toolResults := 0
for _, m := range got {
if m.Role == "tool" {
toolResults++
}
}
if toolResults != 2 {
t.Errorf("expected 2 tool results, got %d", toolResults)
}
// All tool call IDs must be unique
seen := make(map[string]bool)
for _, m := range got {
for _, tc := range m.ToolCalls {
if seen[tc.ID] {
t.Errorf("duplicate tool call ID: %s", tc.ID)
}
seen[tc.ID] = true
}
}
// Each tool result ID must match a tool call ID
callIDs := make(map[string]bool)
for _, m := range got {
for _, tc := range m.ToolCalls {
callIDs[tc.ID] = true
}
}
for _, m := range got {
if m.Role == "tool" && !callIDs[m.ToolCallID] {
t.Errorf("tool result ID %s has no matching tool call", m.ToolCallID)
}
}
}
func TestSanitizeHistory_NoDedupWhenIDsUnique(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "hello"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "tc1", Name: "read_file"},
}},
{Role: "tool", Content: "ok", ToolCallID: "tc1"},
{Role: "user", Content: "next"},
{Role: "assistant", Content: "", ToolCalls: []providers.ToolCall{
{ID: "tc2", Name: "write_file"},
}},
{Role: "tool", Content: "ok", ToolCallID: "tc2"},
}
got, dropped := sanitizeHistory(msgs)
if dropped != 0 {
t.Errorf("expected 0 dropped, got %d", dropped)
}
if len(got) != 6 {
t.Errorf("expected 6 messages, got %d", len(got))
}
// IDs should be unchanged
if got[1].ToolCalls[0].ID != "tc1" {
t.Errorf("expected tc1, got %s", got[1].ToolCalls[0].ID)
}
if got[4].ToolCalls[0].ID != "tc2" {
t.Errorf("expected tc2, got %s", got[4].ToolCalls[0].ID)
}
}
func TestSanitizeHistory_MergesConsecutiveUserMessages(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "hello"},
{Role: "user", Content: "world"},
{Role: "assistant", Content: "hi there"},
}
got, dropped := sanitizeHistory(msgs)
if len(got) != 2 {
t.Fatalf("expected 2 messages after merge, got %d", len(got))
}
if got[0].Content != "hello\n\nworld" {
t.Errorf("expected merged content, got %q", got[0].Content)
}
if dropped != 1 {
t.Errorf("expected 1 dropped, got %d", dropped)
}
}
func TestSanitizeHistory_MergesConsecutiveAssistantMessages(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "question"},
{Role: "assistant", Content: "part 1"},
{Role: "assistant", Content: "part 2"},
{Role: "user", Content: "follow-up"},
}
got, dropped := sanitizeHistory(msgs)
if len(got) != 3 {
t.Fatalf("expected 3 messages after merge, got %d", len(got))
}
if got[1].Content != "part 1\n\npart 2" {
t.Errorf("expected merged assistant content, got %q", got[1].Content)
}
if dropped != 1 {
t.Errorf("expected 1 dropped, got %d", dropped)
}
}
func TestSanitizeHistory_DedupClearsRawAssistantContent(t *testing.T) {
// When dedup rewrites tool call IDs, RawAssistantContent (which has the old IDs)
// must be cleared so the provider uses the corrected ToolCalls.
rawContent := []byte(`[{"type":"text","text":"ok"},{"type":"tool_use","id":"tool_1","name":"search","input":{}}]`)
msgs := []providers.Message{
{Role: "user", Content: "first"},
{Role: "assistant", ToolCalls: []providers.ToolCall{{ID: "tool_1", Name: "search"}}, RawAssistantContent: rawContent},
{Role: "tool", Content: "result1", ToolCallID: "tool_1"},
{Role: "assistant", Content: "ok"},
{Role: "user", Content: "second"},
// Second turn has same tool_1 ID — triggers dedup
{Role: "assistant", ToolCalls: []providers.ToolCall{{ID: "tool_1", Name: "search"}}, RawAssistantContent: rawContent},
{Role: "tool", Content: "result2", ToolCallID: "tool_1"},
{Role: "assistant", Content: "done"},
}
got, _ := sanitizeHistory(msgs)
// First assistant should keep RawAssistantContent (no dedup needed)
if got[1].RawAssistantContent == nil {
t.Error("first assistant should keep RawAssistantContent")
}
// Second assistant (index 5) should have RawAssistantContent cleared due to dedup
if got[5].RawAssistantContent != nil {
t.Error("dedup'd assistant should have RawAssistantContent cleared")
}
// Tool result for second turn should have dedup'd ID
if got[6].ToolCallID == "tool_1" {
t.Errorf("expected dedup'd tool_call_id, got %q", got[6].ToolCallID)
}
}
func TestSanitizeHistory_NoMergeForToolCallMessages(t *testing.T) {
// Assistant messages WITH tool_calls should NOT be merged
msgs := []providers.Message{
{Role: "user", Content: "do something"},
{Role: "assistant", Content: "ok", ToolCalls: []providers.ToolCall{{ID: "tc1", Name: "test"}}},
{Role: "tool", Content: "result", ToolCallID: "tc1"},
{Role: "assistant", Content: "done"},
}
got, dropped := sanitizeHistory(msgs)
if len(got) != 4 {
t.Fatalf("expected 4 messages (no merge), got %d", len(got))
}
if dropped != 0 {
t.Errorf("expected 0 dropped, got %d", dropped)
}
}
func TestSanitizeHistory_MergePreservesMediaRefs(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "here's a photo", MediaRefs: []providers.MediaRef{{Kind: "image", ID: "f1"}}},
{Role: "user", Content: "and another", MediaRefs: []providers.MediaRef{{Kind: "image", ID: "f2"}}},
{Role: "assistant", Content: "nice pics"},
}
got, dropped := sanitizeHistory(msgs)
if len(got) != 2 {
t.Fatalf("expected 2 messages after merge, got %d", len(got))
}
if len(got[0].MediaRefs) != 2 {
t.Errorf("expected 2 media refs after merge, got %d", len(got[0].MediaRefs))
}
if got[0].MediaRefs[0].ID != "f1" || got[0].MediaRefs[1].ID != "f2" {
t.Errorf("media refs not preserved correctly: %+v", got[0].MediaRefs)
}
if dropped != 1 {
t.Errorf("expected 1 dropped, got %d", dropped)
}
}
func TestUniquifyToolCallIDs(t *testing.T) {
runID := "abcdef12-3456-7890-abcd-ef1234567890"
t.Run("empty calls", func(t *testing.T) {
got := uniquifyToolCallIDs(nil, runID, 0)
if len(got) != 0 {
t.Errorf("expected empty, got %d", len(got))
}
})
t.Run("produces fixed-length hashed IDs", func(t *testing.T) {
calls := []providers.ToolCall{
{ID: "call_123", Name: "read_file"},
{ID: "call_456", Name: "write_file"},
}
got := uniquifyToolCallIDs(calls, runID, 2)
// IDs must be exactly 40 chars: "call_" (5) + 35 hex chars
for i, tc := range got {
if len(tc.ID) != 40 {
t.Errorf("call %d: ID length = %d, want 40: %s", i, len(tc.ID), tc.ID)
}
if !strings.HasPrefix(tc.ID, "call_") {
t.Errorf("call %d: ID should start with call_, got: %s", i, tc.ID)
}
}
// Different original IDs must produce different hashed IDs
if got[0].ID == got[1].ID {
t.Errorf("different inputs should produce different IDs: %s", got[0].ID)
}
})
t.Run("handles empty ID", func(t *testing.T) {
calls := []providers.ToolCall{
{ID: "", Name: "read_file"},
}
got := uniquifyToolCallIDs(calls, runID, 0)
if len(got[0].ID) != 40 {
t.Errorf("empty input: ID length = %d, want 40: %s", len(got[0].ID), got[0].ID)
}
if !strings.HasPrefix(got[0].ID, "call_") {
t.Errorf("empty input: ID should start with call_, got: %s", got[0].ID)
}
})
t.Run("does not mutate input", func(t *testing.T) {
calls := []providers.ToolCall{
{ID: "original", Name: "test"},
}
got := uniquifyToolCallIDs(calls, runID, 0)
if calls[0].ID != "original" {
t.Error("input was mutated")
}
if got[0].ID == "original" {
t.Error("output should differ from input")
}
})
t.Run("duplicate IDs become unique", func(t *testing.T) {
calls := []providers.ToolCall{
{ID: "same_id", Name: "a"},
{ID: "same_id", Name: "b"},
}
got := uniquifyToolCallIDs(calls, runID, 0)
if got[0].ID == got[1].ID {
t.Errorf("IDs should be unique, both are: %s", got[0].ID)
}
})
t.Run("includes runID and iteration in hash", func(t *testing.T) {
calls := []providers.ToolCall{
{ID: "same_id", Name: "read_file"},
}
iter0 := uniquifyToolCallIDs(calls, runID, 0)[0].ID
iter1 := uniquifyToolCallIDs(calls, runID, 1)[0].ID
otherRun := uniquifyToolCallIDs(calls, "12345678-1234-5678-1234-567812345678", 0)[0].ID
if iter0 == iter1 {
t.Errorf("iteration should affect hashed ID: %s", iter0)
}
if iter0 == otherRun {
t.Errorf("runID should affect hashed ID: %s", iter0)
}
})
}
func TestEstimateTokens(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "Hello world!"}, // 12 chars → ~4 tokens
{Role: "assistant", Content: "Hi there, how are you?"}, // 22 chars → ~7 tokens
}
got := EstimateTokens(msgs)
if got <= 0 {
t.Errorf("expected positive token estimate, got %d", got)
}
}
func TestEstimateTokensIncludesToolCalls(t *testing.T) {
// Message with tool calls should estimate higher than content-only.
contentOnly := []providers.Message{
{Role: "assistant", Content: "Let me search for that."},
}
withToolCalls := []providers.Message{
{Role: "assistant", Content: "Let me search for that.", ToolCalls: []providers.ToolCall{
{ID: "tc_1", Name: "web_fetch", Arguments: map[string]any{
"url": "https://example.com/very-long-path/to/some/resource?query=test",
}},
}},
}
contentTokens := EstimateTokens(contentOnly)
toolTokens := EstimateTokens(withToolCalls)
if toolTokens <= contentTokens {
t.Errorf("expected tool call tokens (%d) > content-only tokens (%d)", toolTokens, contentTokens)
}
}
func TestEstimateHistoryTokensSkipsSystem(t *testing.T) {
msgs := []providers.Message{
{Role: "system", Content: "You are a helpful assistant with a very long system prompt that includes tool definitions and context files..."},
{Role: "user", Content: "Hello"},
{Role: "assistant", Content: "Hi there!"},
}
allTokens := EstimateTokens(msgs)
historyTokens := EstimateHistoryTokens(msgs)
if historyTokens >= allTokens {
t.Errorf("history tokens (%d) should be less than all tokens (%d)", historyTokens, allTokens)
}
// History should only count user + assistant messages.
expectedHistory := EstimateTokens(msgs[1:])
if historyTokens != expectedHistory {
t.Errorf("history tokens (%d) != expected (%d)", historyTokens, expectedHistory)
}
}
func TestEstimateOverhead(t *testing.T) {
loop := &Loop{contextWindow: 200000}
t.Run("no_calibration_data", func(t *testing.T) {
history := []providers.Message{{Role: "user", Content: "Hello"}}
overhead := loop.estimateOverhead(history, 0, 0)
// Should use fallback: 20% of 200k = 40000
if overhead != 40000 {
t.Errorf("expected fallback 40000, got %d", overhead)
}
})
t.Run("with_calibration", func(t *testing.T) {
history := []providers.Message{
{Role: "user", Content: "Hello world"},
{Role: "assistant", Content: "Hi there!"},
}
// Simulate: LLM reported 50k prompt tokens for 2 messages.
// History estimate for those 2 messages is small (~7 tokens).
// So overhead should be ~49993.
overhead := loop.estimateOverhead(history, 50000, 2)
if overhead <= 0 {
t.Errorf("expected positive overhead, got %d", overhead)
}
// Should be clamped to 40% of context = 80000
maxOverhead := int(float64(200000) * 0.4)
if overhead > maxOverhead {
t.Errorf("overhead %d exceeds max %d", overhead, maxOverhead)
}
})
}
func TestPruneContextMessagesDefaultEnabled(t *testing.T) {
// Phase 04: nil config → no pruning (opt-in). To enable, use Mode: "cache-ttl".
// Create messages with a large tool result that exceeds soft trim threshold.
largeContent := make([]byte, 10000)
for i := range largeContent {
largeContent[i] = 'x'
}
msgs := []providers.Message{
{Role: "user", Content: "Search for info"},
{Role: "assistant", Content: "I'll search.", ToolCalls: []providers.ToolCall{{ID: "tc1", Name: "web_fetch"}}},
{Role: "tool", Content: string(largeContent), ToolCallID: "tc1"},
{Role: "assistant", Content: "Found results."},
{Role: "user", Content: "Thanks"},
{Role: "assistant", Content: "You're welcome."},
{Role: "user", Content: "More info"},
{Role: "assistant", Content: "Sure, here you go."},
}
// With cache-ttl mode and small context window (to trigger soft trim ratio > 0.3),
// pruning should trim the large tool result.
cfg := &config.ContextPruningConfig{Mode: "cache-ttl"}
result := pruneContextMessages(msgs, 5000, cfg, nil, "", nil)
// The large tool result should have been trimmed.
toolMsg := result[2]
if len(toolMsg.Content) >= 10000 {
t.Error("expected large tool result to be trimmed, but it was not")
}
}
func TestPruneContextMessagesExplicitOff(t *testing.T) {
msgs := []providers.Message{
{Role: "user", Content: "Hello"},
}
cfg := &config.ContextPruningConfig{Mode: "off"}
result := pruneContextMessages(msgs, 200000, cfg, nil, "", nil)
// Should return original messages unchanged.
if len(result) != len(msgs) {
t.Errorf("expected %d messages, got %d", len(msgs), len(result))
}
}
func TestTruncateStr(t *testing.T) {
tests := []struct {
name string
input string
maxLen int
want string
}{
{"short", "hello", 10, "hello"},
{"exact", "hello", 5, "hello"},
{"truncate", "hello world", 5, "hello..."},
{"empty", "", 5, ""},
{"unicode", "héllo wörld", 7, "héllo ..."},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got := truncateStr(tt.input, tt.maxLen)
if tt.maxLen >= len(tt.input) {
if got != tt.input {
t.Errorf("got %q, want %q", got, tt.input)
}
} else {
if len(got) == 0 {
t.Error("truncation returned empty")
}
}
})
}
}