fix(schematics): only begin converting to workspace once files have b…

…een checked

packages/schematics/src/collection/workspace/index.ts

@@ -205,9 +205,29 @@ function dedup(array: any[]): any[] {
   return res;
 }
 
+function checkCanConvertToWorkspace(options: Schema) {
+  return (host: Tree) => {
+    if (!host.exists('package.json')) {
+      throw new Error('Cannot find package.json');
+    }
+    if (!host.exists('protractor.conf.js')) {
+      throw new Error('Cannot find protractor.conf.js');
+    }
+    if (!host.exists('.angular-cli.json')) {
+      throw new Error('Cannot find .angular-cli.json');
+    }
+    const angularCliJson = JSON.parse(host.read('.angular-cli.json')!.toString('utf-8'));
+    if (angularCliJson.apps.length !== 1) {
+      throw new Error('Can only convert projects with one app');
+    }
+    return host;
+  };
+}
+
 export default function(schema: Schema): Rule {
   const options = { ...schema, name: toFileName(schema.name) };
   return chain([
+    checkCanConvertToWorkspace(options),
     moveFiles(options),
     branchAndMerge(chain([mergeWith(apply(url('./files'), []))])),
     updatePackageJson(),

packages/schematics/src/collection/workspace/workspace.spec.ts

@@ -0,0 +1,49 @@
+import { SchematicTestRunner } from '@angular-devkit/schematics/testing';
+import * as path from 'path';
+import { Tree, VirtualTree } from '@angular-devkit/schematics';
+import { getFileContent } from '@schematics/angular/utility/test';
+
+describe('workspace', () => {
+  const schematicRunner = new SchematicTestRunner('@nrwl/schematics', path.join(__dirname, '../../collection.json'));
+
+  let appTree: Tree;
+
+  beforeEach(() => {
+    appTree = new VirtualTree();
+  });
+
+  it('should error if no package.json is present', () => {
+    expect(() => {
+      const tree = schematicRunner.runSchematic('workspace', { name: 'myApp' }, appTree);
+    }).toThrow('Cannot find package.json');
+  });
+
+  it('should error if no protractor.conf.js is present', () => {
+    expect(() => {
+      appTree.create('/package.json', JSON.stringify({}));
+      const tree = schematicRunner.runSchematic('workspace', { name: 'myApp' }, appTree);
+    }).toThrow('Cannot find protractor.conf.js');
+  });
+
+  it('should error if no .angular-cli.json is present', () => {
+    expect(() => {
+      appTree.create('/package.json', JSON.stringify({}));
+      appTree.create('/protractor.conf.js', '');
+      const tree = schematicRunner.runSchematic('workspace', { name: 'myApp' }, appTree);
+    }).toThrow('Cannot find .angular-cli.json');
+  });
+
+  it('should error if the .angular-cli.json specifies more than one app', () => {
+    expect(() => {
+      appTree.create('/package.json', JSON.stringify({}));
+      appTree.create('/protractor.conf.js', '');
+      appTree.create(
+        '/.angular-cli.json',
+        JSON.stringify({
+          apps: [{}, {}]
+        })
+      );
+      const tree = schematicRunner.runSchematic('workspace', { name: 'myApp' }, appTree);
+    }).toThrow('Can only convert projects with one app');
+  });
+});