editor model - add some tests

src/vs/workbench/common/editor.ts

@@ -835,6 +835,9 @@ export class EditorModel extends Disposable implements IEditorModel {
 		return true;
 	}
 
+	/**
+	 * Find out if this model has been disposed.
+	 */
 	isDisposed(): boolean {
 		return this.disposed;
 	}

src/vs/workbench/services/textfile/test/browser/textFileEditorModel.test.ts

@@ -7,7 +7,7 @@ import * as assert from 'assert';
 import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
 import { EncodingMode } from 'vs/workbench/common/editor';
 import { TextFileEditorModel } from 'vs/workbench/services/textfile/common/textFileEditorModel';
-import { TextFileEditorModelState, snapshotToString } from 'vs/workbench/services/textfile/common/textfiles';
+import { TextFileEditorModelState, snapshotToString, isTextFileEditorModel } from 'vs/workbench/services/textfile/common/textfiles';
 import { createFileEditorInput, workbenchInstantiationService, TestServiceAccessor, TestReadonlyTextFileEditorModel } from 'vs/workbench/test/browser/workbenchTestServices';
 import { toResource } from 'vs/base/test/common/utils';
 import { TextFileEditorModelManager } from 'vs/workbench/services/textfile/common/textFileEditorModelManager';
@@ -73,6 +73,14 @@ suite('Files - TextFileEditorModel', () => {
 		model.dispose();
 	});
 
+	test('isTextFileEditorModel', async function () {
+		const model = instantiationService.createInstance(TextFileEditorModel, toResource.call(this, '/path/index_async.txt'), 'utf8', undefined);
+
+		assert.equal(isTextFileEditorModel(model), true);
+
+		model.dispose();
+	});
+
 	test('save', async function () {
 		const model: TextFileEditorModel = instantiationService.createInstance(TextFileEditorModel, toResource.call(this, '/path/index_async.txt'), 'utf8', undefined);
 

src/vs/workbench/test/browser/parts/editor/editorModel.test.ts

@@ -60,9 +60,11 @@ suite('Workbench editor model', () => {
 
 		const model = await m.load();
 		assert(model === m);
+		assert.equal(model.isDisposed(), false);
 		assert.strictEqual(m.isResolved(), true);
 		m.dispose();
 		assert.equal(counter, 1);
+		assert.equal(model.isDisposed(), true);
 	});
 
 	test('BaseTextEditorModel', async () => {