feat(cli): auto-generate / update index.ts for exports

fix #1127

Signed-off-by: Taranveer Virk <[email protected]>

Author: virkt25

docs/site/todo-tutorial-controller.md

@@ -20,11 +20,14 @@ logic will live_!
 
 ### Create your controller
 
-So, let's create a controller to handle our Todo routes. Inside the
-`src/controllers` directory create the following two files:
+So, let's create a controller to handle our Todo routes. You can create an empty
+Controller using the CLI as follows:
 
-- `index.ts` (export helper)
-- `todo.controller.ts`
+```sh
+lb4 controller
+? Controller class name: todo
+? What kind of controller would you like to generate? Empty Controller
+```
 
 In addition to creating the handler functions themselves, we'll also be adding
 decorators that setup the routing as well as the expected parameters of incoming

packages/cli/generators/app/templates/src/controllers/index.ts.ejs

@@ -0,0 +1 @@
+export * from './ping.controller';

packages/cli/generators/controller/index.js

@@ -9,6 +9,7 @@ const ArtifactGenerator = require('../../lib/artifact-generator');
 const debug = require('../../lib/debug')('controller-generator');
 const inspect = require('util').inspect;
 const path = require('path');
+const chalk = require('chalk');
 const utils = require('../../lib/utils');
 
 // Exportable constants
@@ -35,7 +36,7 @@ module.exports = class ControllerGenerator extends ArtifactGenerator {
     // XXX(kjdelisle): These should be more extensible to allow custom paths
     // for each artifact type.
 
-    this.artifactInfo.outdir = path.resolve(
+    this.artifactInfo.outDir = path.resolve(
       this.artifactInfo.rootDir,
       'controllers',
     );
@@ -185,10 +186,10 @@ module.exports = class ControllerGenerator extends ArtifactGenerator {
     // all of the templates!
     if (this.shouldExit()) return false;
     this.artifactInfo.name = utils.toClassName(this.artifactInfo.name);
-    this.artifactInfo.filename =
+    this.artifactInfo.outFile =
       utils.kebabCase(this.artifactInfo.name) + '.controller.ts';
     if (debug.enabled) {
-      debug(`Artifact filename set to: ${this.artifactInfo.filename}`);
+      debug(`Artifact output filename set to: ${this.artifactInfo.outFile}`);
     }
     // renames the file
     let template = 'controller-template.ts.ejs';
@@ -204,7 +205,7 @@ module.exports = class ControllerGenerator extends ArtifactGenerator {
       debug(`Using template at: ${source}`);
     }
     const dest = this.destinationPath(
-      path.join(this.artifactInfo.outdir, this.artifactInfo.filename),
+      path.join(this.artifactInfo.outDir, this.artifactInfo.outFile),
     );
 
     if (debug.enabled) {
@@ -221,20 +222,7 @@ module.exports = class ControllerGenerator extends ArtifactGenerator {
     return;
   }
 
-  end() {
-    super.end();
-    if (this.shouldExit()) return false;
-    // logs a message if there is no file conflict
-    if (
-      this.conflicter.generationStatus[this.artifactInfo.filename] !== 'skip' &&
-      this.conflicter.generationStatus[this.artifactInfo.filename] !==
-        'identical'
-    ) {
-      this.log();
-      this.log(
-        'Controller %s is now created in src/controllers/',
-        this.artifactInfo.name,
-      );
-    }
+  async end() {
+    await super.end();
   }
 };

packages/cli/lib/artifact-generator.js

@@ -7,6 +7,9 @@
 const BaseGenerator = require('./base-generator');
 const debug = require('./debug')('artifact-generator');
 const utils = require('./utils');
+const updateIndex = require('./update-index');
+const path = require('path');
+const chalk = require('chalk');
 const StatusConflicter = utils.StatusConflicter;
 
 module.exports = class ArtifactGenerator extends BaseGenerator {
@@ -29,6 +32,10 @@ module.exports = class ArtifactGenerator extends BaseGenerator {
     }
     this.artifactInfo.name = this.args[0];
     this.artifactInfo.defaultName = 'new';
+    this.artifactInfo.relPath = path.relative(
+      this.destinationPath(),
+      this.artifactInfo.outDir,
+    );
     this.conflicter = new StatusConflicter(
       this.env.adapter,
       this.options.force,
@@ -102,4 +109,51 @@ module.exports = class ArtifactGenerator extends BaseGenerator {
       {globOptions: {dot: true}},
     );
   }
+
+  async end() {
+    const success = super.end();
+    if (!success) return false;
+
+    let generationStatus = true;
+    // Check all files being generated to ensure they succeeded
+    Object.entries(this.conflicter.generationStatus).forEach(([key, val]) => {
+      if (val === 'skip' || val === 'identical') generationStatus = false;
+    });
+
+    if (generationStatus) {
+      /**
+       * Update the index.ts in this.artifactInfo.outDir. Creates it if it
+       * doesn't exist.
+       * this.artifactInfo.outFile is what is exported from the file.
+       *
+       * Both those properties must be present for this to happen. Optionally,
+       * this can be disabled even if the properties are present by setting:
+       * this.artifactInfo.disableIndexUdpdate = true;
+       */
+      if (
+        this.artifactInfo.outDir &&
+        this.artifactInfo.outFile &&
+        !this.artifactInfo.disableIndexUpdate
+      ) {
+        await updateIndex(this.artifactInfo.outDir, this.artifactInfo.outFile);
+        // Output for users
+        this.log(
+          chalk.green('   update'),
+          `${this.artifactInfo.relPath}/index.ts`,
+        );
+      }
+
+      // User Output
+      this.log();
+      this.log(
+        utils.toClassName(this.artifactInfo.type),
+        chalk.yellow(this.artifactInfo.name),
+        'is now created in',
+        `${this.artifactInfo.relPath}/`,
+      );
+      this.log();
+    }
+
+    return false;
+  }
 };

packages/cli/lib/update-index.js

@@ -0,0 +1,23 @@
+// Copyright IBM Corp. 2017,2018. All Rights Reserved.
+// Node module: @loopback/cli
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+const path = require('path');
+const util = require('util');
+const fs = require('fs');
+const appendFileAsync = util.promisify(fs.appendFile);
+
+/**
+ *
+ * @param {String} dir The directory in which index.ts is to be updated/created
+ * @param {*} file The new file to be exported from index.ts
+ */
+module.exports = async function(dir, file) {
+  const indexFile = path.join(dir, 'index.ts');
+  if (!file.endsWith('.ts')) {
+    throw new Error(`${file} must be a TypeScript (.ts) file`);
+  }
+  const content = `export * from './${file.slice(0, -3)}';\n`;
+  await appendFileAsync(indexFile, content);
+};

packages/cli/test/unit/update-index.unit.js

@@ -0,0 +1,47 @@
+// Copyright IBM Corp. 2017,2018. All Rights Reserved.
+// Node module: @loopback/cli
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+const updateIndex = require('../../lib/update-index');
+const assert = require('yeoman-assert');
+const path = require('path');
+const util = require('util');
+const fs = require('fs');
+const writeFileAsync = util.promisify(fs.writeFile);
+
+const testlab = require('@loopback/testlab');
+const expect = testlab.expect;
+const TestSandbox = testlab.TestSandbox;
+
+// Test Sandbox
+const SANDBOX_PATH = path.resolve(__dirname, '.sandbox');
+const sandbox = new TestSandbox(SANDBOX_PATH);
+const expectedFile = path.join(SANDBOX_PATH, 'index.ts');
+
+describe('update-index unit tests', () => {
+  beforeEach('reset sandbox', () => sandbox.reset());
+
+  it('creates index.ts when not present', async () => {
+    await updateIndex(SANDBOX_PATH, 'test.ts');
+    assert.file(expectedFile);
+    assert.fileContent(expectedFile, /export \* from '.\/test';/);
+  });
+
+  it('appends to existing index.ts when present', async () => {
+    await writeFileAsync(
+      path.join(SANDBOX_PATH, 'index.ts'),
+      `export * from './first';\n`,
+    );
+    await updateIndex(SANDBOX_PATH, 'test.ts');
+    assert.file(expectedFile);
+    assert.fileContent(expectedFile, /export \* from '.\/first'/);
+    assert.fileContent(expectedFile, /export \* from '.\/test'/);
+  });
+
+  it('throws an error when given a non-ts file', async () => {
+    expect(updateIndex(SANDBOX_PATH, 'test.js')).to.be.rejectedWith(
+      /test.js must be a TypeScript \(.ts\) file/,
+    );
+  });
+});