util: Move isSerializationFirstNode to runtime package to resolve…

… cyclic dependency

packages/@glimmer/runtime/index.ts

@@ -85,6 +85,11 @@ export {
   ElementOperations,
   clientBuilder,
 } from './lib/vm/element-builder';
-export { rehydrationBuilder, RehydrateBuilder } from './lib/vm/rehydrate-builder';
+export {
+  rehydrationBuilder,
+  RehydrateBuilder,
+  SERIALIZATION_FIRST_NODE_STRING,
+  isSerializationFirstNode,
+} from './lib/vm/rehydrate-builder';
 export { default as Bounds, ConcreteBounds, Cursor } from './lib/bounds';
 export { capabilityFlagsFrom, hasCapability, Capability } from './lib/capabilities';

packages/@glimmer/runtime/lib/vm/rehydrate-builder.ts

@@ -3,15 +3,15 @@ import { NewElementBuilder, ElementBuilder, RemoteBlockTracker } from './element
 import { Environment } from '../environment';
 import Bounds, { Cursor, ConcreteBounds } from '../bounds';
 import { Simple, Option } from '@glimmer/interfaces';
-import {
-  expect,
-  assert,
-  Stack,
-  isSerializationFirstNode,
-  SERIALIZATION_FIRST_NODE_STRING,
-} from '@glimmer/util';
+import { expect, assert, Stack } from '@glimmer/util';
 import { SVG_NAMESPACE } from '../dom/helper';
 
+export const SERIALIZATION_FIRST_NODE_STRING = '%+b:0%';
+
+export function isSerializationFirstNode(node: Simple.Node): boolean {
+  return node.nodeValue === SERIALIZATION_FIRST_NODE_STRING;
+}
+
 export class RehydratingCursor extends Cursor {
   candidate: Option<Simple.Node> = null;
   openBlockDepth: number;

packages/@glimmer/util/index.ts

@@ -8,11 +8,6 @@ export { default as assert } from './lib/assert';
 export { assign, fillNulls } from './lib/object-utils';
 export { ensureGuid, initializeGuid, HasGuid } from './lib/guid';
 
-export {
-  isSerializationFirstNode,
-  SERIALIZATION_FIRST_NODE_STRING,
-} from './lib/is-serialization-first-node';
-
 export { Stack, Dict, Set, DictSet, dict } from './lib/collections';
 export {
   EMPTY_SLICE,

packages/@glimmer/util/package.json

@@ -8,4 +8,4 @@
     "@types/qunit": "^2.0.31",
     "typescript": "^2.8.3"
   }
-}
+}