chore: add tests, merge cookiecutter.json

Co-authored-by: Ben Lambert <ben@blam.sh>

plugins/scaffolder-backend/package.json

@@ -23,6 +23,7 @@
   "dependencies": {
     "@backstage/backend-common": "^0.1.1-alpha.9",
     "@backstage/catalog-model": "^0.1.1-alpha.9",
+    "@backstage/config": "^0.1.1-alpha.9",
     "@types/express": "^4.17.6",
     "compression": "^1.7.4",
     "cors": "^2.8.5",

plugins/scaffolder-backend/sample-templates/react-ssr-template/cookiecutter.json

@@ -0,0 +1,3 @@
+{
+  "_copy_without_render": [".github/workflows/*"]
+}

plugins/scaffolder-backend/src/scaffolder/templater/cookiecutter.test.ts

@@ -0,0 +1,119 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { CookieCutter } from './cookiecutter';
+import fs from 'fs-extra';
+import os from 'os';
+
+const mockDocker = { run: jest.fn() };
+jest.mock(
+  'dockerode',
+  () =>
+    class {
+      constructor() {
+        return mockDocker;
+      }
+    },
+);
+
+describe('CookieCutter Templater', () => {
+  const cookie = new CookieCutter();
+
+  beforeEach(() => {
+    jest.resetAllMocks();
+  });
+
+  it('should write a cookiecutter.json file with the values from the entitiy', async () => {
+    const tempdir = os.tmpdir();
+
+    const values = {
+      component_id: 'test',
+      description: 'description',
+    };
+
+    await cookie.run({ directory: tempdir, values });
+
+    const cookieCutterJson = await fs.readJSON(`${tempdir}/cookiecutter.json`);
+
+    expect(cookieCutterJson).toEqual(expect.objectContaining(values));
+  });
+
+  it('should merge any value that is in the cookiecutter.json path already', async () => {
+    const tempdir = os.tmpdir();
+    const existingJson = {
+      _copy_without_render: ['./github/workflows/*'],
+    };
+    await fs.writeJSON(`${tempdir}/cookiecutter.json`, existingJson);
+
+    const values = {
+      component_id: 'hello',
+      description: 'im something cool',
+    };
+
+    await cookie.run({ directory: tempdir, values });
+
+    const cookieCutterJson = await fs.readJSON(`${tempdir}/cookiecutter.json`);
+
+    expect(cookieCutterJson).toEqual({ ...existingJson, ...values });
+  });
+
+  it('should run the correct docker container with the correct bindings for the volumes', async () => {
+    const tempdir = os.tmpdir();
+
+    const values = {
+      component_id: 'test',
+      description: 'description',
+    };
+
+    await cookie.run({ directory: tempdir, values });
+
+    const realpath = await fs.realpath(tempdir);
+
+    // TODO(blam): This might change when we publish our own cookiecutter image
+    // to @backstage/cookiecutter in docker hub.
+    expect(mockDocker.run).toHaveBeenCalledWith(
+      'backstage/cookiecutter',
+      ['cookiecutter', '--no-input', '-o', '/result', '/template', '--verbose'],
+      process.stdout,
+      expect.objectContaining({
+        HostConfig: {
+          Binds: expect.arrayContaining([
+            `${realpath}:/template`,
+            `${realpath}/result:/result`,
+          ]),
+        },
+        Volumes: {
+          '/template': {},
+          '/result': {},
+        },
+      }),
+    );
+  });
+
+  it('should return the result path to the end templated folder', async () => {
+    const tempdir = os.tmpdir();
+
+    const values = {
+      component_id: 'test',
+      description: 'description',
+    };
+
+    const path = await cookie.run({ directory: tempdir, values });
+
+    const realpath = await fs.realpath(tempdir);
+
+    expect(path).toBe(`${realpath}/result`);
+  });
+});

plugins/scaffolder-backend/src/scaffolder/templater/cookiecutter.ts

@@ -17,32 +17,52 @@ import { TemplaterBase, TemplaterRunOptions } from '.';
  */
 import fs from 'fs-extra';
 import Docker from 'dockerode';
+import { JsonValue } from '@backstage/config';
 
 export class CookieCutter implements TemplaterBase {
-  private docker:Docker;
+  private docker: Docker;
   constructor() {
     this.docker = new Docker();
   }
 
+  private async fetchTemplateCookieCutter(
+    directory: string,
+  ): Promise<Record<string, JsonValue>> {
+    try {
+      return await fs.readJSON(`${directory}/cookiecutter.json`);
+    } catch (ex) {
+      return {};
+    }
+  }
+
   public async run(options: TemplaterRunOptions): Promise<string> {
-    
-      
-    
-    // first we need to make cookiecutter.json in the directory provided with the input values.
+    // First lets grab the default cookiecutter.json file
+    const cookieCutterJson = await this.fetchTemplateCookieCutter(
+      options.directory,
+    );
+
     const cookieInfo = {
-      _copy_without_render: ['.github/workflows/*'],
+      ...cookieCutterJson,
       ...options.values,
     };
 
     await fs.writeJSON(`${options.directory}/cookiecutter.json`, cookieInfo);
+
     const realTemplatePath = await fs.promises.realpath(options.directory);
-    const outDir = realTemplatePath + '/result';
+    const outDir = `${realTemplatePath}/result`;
 
+    await this.docker.run(
+      'backstage/cookiecutter',
+      ['cookiecutter', '--no-input', '-o', '/result', '/template', '--verbose'],
+      process.stdout,
+      {
+        Volumes: { '/result': {}, '/template': {} },
+        HostConfig: {
+          Binds: [`${outDir}:/result`, `${realTemplatePath}:/template`],
+        },
+      },
+    );
 
-    await this.docker.run('backstage/cookiecutter', ['cookiecutter', '--no-input', '-o', '/result', '/template', '--verbose'], process.stdout, {Volumes: { '/result': {}, '/template': {}}, HostConfig: {
-      Binds: [`${outDir}:/result`, `${realTemplatePath}:/template`],
-    }});
-    
     return outDir;
   }
 }