test: expand compact and ui coverage

internal/compact/haiku_test.go

@@ -3,13 +3,21 @@ package compact
 import (
 	"context"
 	"errors"
+	"fmt"
 	"strings"
 	"testing"
 	"time"
 
+	"github.com/anthropics/anthropic-sdk-go"
 	"github.com/steveyegge/beads/internal/types"
 )
 
+type timeoutErr struct{}
+
+func (timeoutErr) Error() string   { return "timeout" }
+func (timeoutErr) Timeout() bool   { return true }
+func (timeoutErr) Temporary() bool { return true }
+
 func TestNewHaikuClient_RequiresAPIKey(t *testing.T) {
 	t.Setenv("ANTHROPIC_API_KEY", "")
 
@@ -178,6 +186,11 @@ func TestIsRetryable(t *testing.T) {
 		{"context canceled", context.Canceled, false},
 		{"context deadline exceeded", context.DeadlineExceeded, false},
 		{"generic error", errors.New("some error"), false},
+		{"timeout error", timeoutErr{}, true},
+		{"anthropic 429", &anthropic.Error{StatusCode: 429}, true},
+		{"anthropic 500", &anthropic.Error{StatusCode: 500}, true},
+		{"anthropic 400", &anthropic.Error{StatusCode: 400}, false},
+		{"wrapped timeout", fmt.Errorf("wrap: %w", timeoutErr{}), true},
 	}
 
 	for _, tt := range tests {
@@ -189,3 +202,16 @@ func TestIsRetryable(t *testing.T) {
 		})
 	}
 }
+
+func TestBytesWriterAppends(t *testing.T) {
+	w := &bytesWriter{}
+	if _, err := w.Write([]byte("hello")); err != nil {
+		t.Fatalf("first write failed: %v", err)
+	}
+	if _, err := w.Write([]byte(" world")); err != nil {
+		t.Fatalf("second write failed: %v", err)
+	}
+	if got := string(w.buf); got != "hello world" {
+		t.Fatalf("unexpected buffer content: %q", got)
+	}
+}