scaffolder: add test suite for fetch:template

Signed-off-by: Mike Lewis <mtlewis@users.noreply.github.com>

plugins/scaffolder-backend/src/scaffolder/actions/builtin/fetch/template.test.ts

@@ -0,0 +1,221 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * 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 os from 'os';
+import fs from 'fs-extra';
+import mockFs from 'mock-fs';
+import { getVoidLogger, UrlReader } from '@backstage/backend-common';
+import { ScmIntegrations } from '@backstage/integration';
+import { PassThrough } from 'stream';
+import { fetchContents } from './helpers';
+import { ActionContext, TemplateAction } from '../../types';
+import { createFetchTemplateAction, FetchTemplateInput } from './template';
+
+jest.mock('./helpers', () => ({
+  fetchContents: jest.fn(),
+}));
+
+const mockFetchContents = fetchContents as jest.MockedFunction<
+  typeof fetchContents
+>;
+
+describe('fetch:template', () => {
+  let action: TemplateAction<any>;
+
+  const workspacePath = os.tmpdir();
+  const createTemporaryDirectory: jest.MockedFunction<
+    ActionContext<FetchTemplateInput>['createTemporaryDirectory']
+  > = jest.fn(() =>
+    Promise.resolve(
+      `${workspacePath}/${createTemporaryDirectory.mock.calls.length}`,
+    ),
+  );
+
+  const logger = getVoidLogger();
+
+  const mockContext = (inputPatch: Partial<FetchTemplateInput> = {}) => ({
+    baseUrl: 'base-url',
+    input: {
+      url: './skeleton',
+      targetPath: './target',
+      values: {
+        test: 'value',
+      },
+      ...inputPatch,
+    },
+    output: jest.fn(),
+    logStream: new PassThrough(),
+    logger,
+    workspacePath,
+    createTemporaryDirectory,
+  });
+
+  beforeEach(() => {
+    mockFs();
+
+    action = createFetchTemplateAction({
+      reader: (Symbol('UrlReader') as unknown) as UrlReader,
+      integrations: (Symbol('Integrations') as unknown) as ScmIntegrations,
+    });
+  });
+
+  afterEach(() => {
+    mockFs.restore();
+  });
+
+  it(`returns a TemplateAction with the id 'fetch:template'`, () => {
+    expect(action.id).toEqual('fetch:template');
+  });
+
+  describe('handler', () => {
+    it('throws if output directory is outside the workspace', async () => {
+      await expect(() =>
+        action.handler(mockContext({ targetPath: '../' })),
+      ).rejects.toThrowError(/outside the working directory/i);
+    });
+
+    it('throws if copyWithoutRender parameter is not an array', async () => {
+      await expect(() =>
+        action.handler(
+          mockContext({ copyWithoutRender: ('abc' as unknown) as string[] }),
+        ),
+      ).rejects.toThrowError(/copyWithoutRender must be an array/i);
+    });
+
+    describe('with valid input', () => {
+      let context: ActionContext<FetchTemplateInput>;
+
+      beforeEach(async () => {
+        context = mockContext({
+          values: {
+            name: 'test-project',
+            count: 1234,
+            itemList: ['first', 'second', 'third'],
+          },
+        });
+
+        mockFetchContents.mockImplementation(({ outputPath }) => {
+          mockFs({
+            [outputPath]: {
+              'empty-dir-${{ count }}': {},
+              'static.txt': 'static content',
+              '${{ name }}.txt': 'static content',
+              subdir: {
+                'templated-content.txt': '${{ name }}: ${{ count }}',
+              },
+              '.${{ name }}': '${{ itemList | dump }}',
+            },
+          });
+
+          return Promise.resolve();
+        });
+
+        await action.handler(context);
+      });
+
+      it('uses fetchContents to retrieve the template content', () => {
+        expect(mockFetchContents).toHaveBeenCalledWith(
+          expect.objectContaining({
+            baseUrl: context.baseUrl,
+            fetchUrl: context.input.url,
+          }),
+        );
+      });
+
+      it('copies files with no templating in names or content successfully', async () => {
+        await expect(
+          fs.readFile(`${workspacePath}/target/static.txt`, 'utf-8'),
+        ).resolves.toEqual('static content');
+      });
+
+      it('copies files with templated names successfully', async () => {
+        await expect(
+          fs.readFile(`${workspacePath}/target/test-project.txt`, 'utf-8'),
+        ).resolves.toEqual('static content');
+      });
+
+      it('copies files with templated content successfully', async () => {
+        await expect(
+          fs.readFile(
+            `${workspacePath}/target/subdir/templated-content.txt`,
+            'utf-8',
+          ),
+        ).resolves.toEqual('test-project: 1234');
+      });
+
+      it('processes dotfiles', async () => {
+        await expect(
+          fs.readFile(`${workspacePath}/target/.test-project`, 'utf-8'),
+        ).resolves.toEqual('["first","second","third"]');
+      });
+
+      it('copies empty directories', async () => {
+        await expect(
+          fs.readdir(`${workspacePath}/target/empty-dir-1234`, 'utf-8'),
+        ).resolves.toEqual([]);
+      });
+    });
+
+    describe('copyWithoutRender', () => {
+      let context: ActionContext<FetchTemplateInput>;
+
+      beforeEach(async () => {
+        context = mockContext({
+          values: {
+            name: 'test-project',
+            count: 1234,
+          },
+          copyWithoutRender: ['.unprocessed'],
+        });
+
+        mockFetchContents.mockImplementation(({ outputPath }) => {
+          mockFs({
+            [outputPath]: {
+              processed: {
+                'templated-content-${{ name }}.txt': '${{ count }}',
+              },
+              '.unprocessed': {
+                'templated-content-${{ name }}.txt': '${{ count }}',
+              },
+            },
+          });
+
+          return Promise.resolve();
+        });
+
+        await action.handler(context);
+      });
+
+      it('ignores template syntax in files matched in copyWithoutRender', async () => {
+        await expect(
+          fs.readFile(
+            `${workspacePath}/target/.unprocessed/templated-content-\${{ name }}.txt`,
+            'utf-8',
+          ),
+        ).resolves.toEqual('${{ count }}');
+      });
+
+      it('processes files not matched in copyWithoutRender', async () => {
+        await expect(
+          fs.readFile(
+            `${workspacePath}/target/processed/templated-content-test-project.txt`,
+            'utf-8',
+          ),
+        ).resolves.toEqual('1234');
+      });
+    });
+  });
+});