add more tests

test/editor/mock.js

@@ -67,3 +67,13 @@ export function createPartCreator(completions = []) {
     };
     return new PartCreator(new MockRoom(), new MockClient(), autoCompleteCreator);
 }
+
+export function createRenderer() {
+    const render = (c) => {
+        render.caret = c;
+        render.count += 1;
+    };
+    render.count = 0;
+    render.caret = null;
+    return render;
+}

test/editor/model-test.js

@@ -15,17 +15,7 @@ limitations under the License.
 */
 
 import EditorModel from "../../src/editor/model";
-import {createPartCreator} from "./mock";
-
-function createRenderer() {
-    const render = (c) => {
-        render.caret = c;
-        render.count += 1;
-    };
-    render.count = 0;
-    render.caret = null;
-    return render;
-}
+import {createPartCreator, createRenderer} from "./mock";
 
 describe('editor/model', function() {
     describe('plain text manipulation', function() {