diff --git a/builder.go b/builder.go
index 266bc12..1e5afc2 100644
--- a/builder.go
+++ b/builder.go
@@ -199,10 +199,6 @@ func (b *Builder[Type, Status]) OnComplete(hook RunStateChangeHookFunc[Type, Sta
 	b.workflow.runStateChangeHooks[RunStateCompleted] = hook
 }
 
-func (b *Builder[Type, Status]) OnDeleted(hook RunStateChangeHookFunc[Type, Status]) {
-	b.workflow.runStateChangeHooks[RunStateDataDeleted] = hook
-}
-
 func (b *Builder[Type, Status]) Build(eventStreamer EventStreamer, recordStore RecordStore, roleScheduler RoleScheduler, opts ...BuildOption) *Workflow[Type, Status] {
 	b.workflow.eventStreamer = eventStreamer
 	b.workflow.recordStore = recordStore
diff --git a/builder_internal_test.go b/builder_internal_test.go
index 8a5b9e6..8fb0ede 100644
--- a/builder_internal_test.go
+++ b/builder_internal_test.go
@@ -125,6 +125,8 @@ func TestBuildOptions(t *testing.T) {
 		pauseAfterErrCount: 3,
 	}
 	deleter := func(object *string) error {
+		b := []byte(*object)
+		*object = string(b[:len(b)/2])
 		return nil
 	}
 
@@ -154,6 +156,11 @@ func TestBuildOptions(t *testing.T) {
 	require.Equal(t, logger, w.logger.inner)
 	require.Equal(t, opts, w.defaultOpts)
 	require.True(t, strings.Contains(runtime.FuncForPC(reflect.ValueOf(w.customDelete).Pointer()).Name(), "github.com/luno/workflow.TestBuildOptions.WithCustomDelete"))
+	object, err := w.customDelete(&Record{
+		Object: []byte(`"hello world"`),
+	})
+	require.NoError(t, err)
+	require.Equal(t, `"hello"`, string(object))
 }
 
 func TestAddingCallbacks(t *testing.T) {
@@ -168,7 +175,7 @@ func TestAddingCallbacks(t *testing.T) {
 	require.NotNil(t, wf.callback[statusStart][0].CallbackFunc)
 }
 
-func TestWithTimeoutErrBackOff(t *testing.T) {
+func TestAddTimeoutErrBackOff(t *testing.T) {
 	b := NewBuilder[string, testStatus]("determine starting points")
 	b.AddTimeout(
 		statusStart,
@@ -184,7 +191,7 @@ func TestWithTimeoutErrBackOff(t *testing.T) {
 	require.Equal(t, time.Minute, b.workflow.timeouts[statusStart].errBackOff)
 }
 
-func TestWithTimeoutPollingFrequency(t *testing.T) {
+func TestAddTimeoutPollingFrequency(t *testing.T) {
 	b := NewBuilder[string, testStatus]("determine starting points")
 	b.AddTimeout(
 		statusStart,
@@ -200,6 +207,30 @@ func TestWithTimeoutPollingFrequency(t *testing.T) {
 	require.Equal(t, time.Minute, b.workflow.timeouts[statusStart].pollingFrequency)
 }
 
+func TestAddTimeoutDontAllowParallelCount(t *testing.T) {
+	require.PanicsWithValue(t,
+		"Cannot configure parallel timeout",
+		func() {
+			b := NewBuilder[string, testStatus]("")
+			b.AddTimeout(statusStart, nil, nil, statusEnd).WithOptions(
+				ParallelCount(2),
+			)
+		},
+	)
+}
+
+func TestAddTimeoutDontAllowLag(t *testing.T) {
+	require.PanicsWithValue(t,
+		"Cannot configure lag for timeout",
+		func() {
+			b := NewBuilder[string, testStatus]("")
+			b.AddTimeout(statusStart, nil, nil, statusEnd).WithOptions(
+				ConsumeLag(time.Hour),
+			)
+		},
+	)
+}
+
 func TestConnectorConstruction(t *testing.T) {
 	fn := func(ctx context.Context, w *Workflow[string, testStatus], e *ConnectorEvent) error {
 		return nil
@@ -400,3 +431,50 @@ func TestWithDefaultOptions(t *testing.T) {
 	require.Equal(t, 6*time.Hour, wf.defaultOpts.lag)
 	require.Equal(t, 700, wf.defaultOpts.pauseAfterErrCount)
 }
+
+func TestConnectorNamesAreUnique(t *testing.T) {
+	require.PanicsWithValue(t,
+		"connector names need to be unique",
+		func() {
+			b := NewBuilder[string, testStatus]("workflow X")
+			b.AddConnector("my-test-connector", nil, nil)
+			b.AddConnector("my-test-connector", nil, nil)
+		},
+	)
+}
+
+func TestOnPause(t *testing.T) {
+	b := NewBuilder[string, testStatus]("")
+	testErr := errors.New("test error")
+	fn := func(ctx context.Context, record *TypedRecord[string, testStatus]) error {
+		return testErr
+	}
+	b.OnPause(fn)
+	actualFn, ok := b.workflow.runStateChangeHooks[RunStatePaused]
+	require.True(t, ok)
+	require.Equal(t, testErr, actualFn(nil, nil))
+}
+
+func TestOnCancel(t *testing.T) {
+	b := NewBuilder[string, testStatus]("")
+	testErr := errors.New("test error")
+	fn := func(ctx context.Context, record *TypedRecord[string, testStatus]) error {
+		return testErr
+	}
+	b.OnCancel(fn)
+	actualFn, ok := b.workflow.runStateChangeHooks[RunStateCancelled]
+	require.True(t, ok)
+	require.Equal(t, testErr, actualFn(nil, nil))
+}
+
+func TestOnComplete(t *testing.T) {
+	b := NewBuilder[string, testStatus]("")
+	testErr := errors.New("test error")
+	fn := func(ctx context.Context, record *TypedRecord[string, testStatus]) error {
+		return testErr
+	}
+	b.OnComplete(fn)
+	actualFn, ok := b.workflow.runStateChangeHooks[RunStateCompleted]
+	require.True(t, ok)
+	require.Equal(t, testErr, actualFn(nil, nil))
+}