Bundle command

Summary:
Command which transpiles and bundles plugin code.

It is supposed to be used in "prepack" script for all open-sourced plugin packages to bundle them before publishing like this:
```
{
  "devDependencies": {
    "flipper-pkg": "latest"
  },
  "scripts": {
    "prepack": "flipper-pkg bundle"
  }
}
```

Also made directory parameter of other command "pack" optional so it also can be called from plugin directory simply by `flipper-pkg pack`.

Changelog: "flipper-pkg bundle" command for bundling plugins before publishing.

Reviewed By: mweststrate

Differential Revision: D21129691

fbshipit-source-id: 8f97bc950c28cf9ad8b0117c0e1d811ed1b988eb

desktop/pkg/src/commands/bundle.ts

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+import {Command} from '@oclif/command';
+import {args} from '@oclif/parser';
+import fs from 'fs-extra';
+import path from 'path';
+import {runBuild, getPluginDetails} from 'flipper-pkg-lib';
+
+export default class Bundle extends Command {
+  public static description = 'transpiles and bundles plugin';
+
+  public static examples = [`$ flipper-pkg bundle optional/path/to/directory`];
+
+  public static args: args.IArg[] = [
+    {
+      name: 'directory',
+      required: false,
+      default: '.',
+      description:
+        'Path to plugin package directory for bundling. Defaults to the current working directory.',
+    },
+  ];
+
+  public async run() {
+    const {args} = this.parse(Bundle);
+    const inputDirectory: string = path.resolve(process.cwd(), args.directory);
+    const stat = await fs.lstat(inputDirectory);
+    if (!stat.isDirectory()) {
+      this.error(`Plugin source ${inputDirectory} is not a directory.`);
+    }
+    const packageJsonPath = path.join(inputDirectory, 'package.json');
+    if (!(await fs.pathExists(packageJsonPath))) {
+      this.error(
+        `package.json is not found in plugin source directory ${inputDirectory}.`,
+      );
+    }
+    const plugin = await getPluginDetails(inputDirectory);
+    const out = path.resolve(inputDirectory, plugin.main);
+    await fs.ensureDir(path.dirname(out));
+    await runBuild(inputDirectory, plugin.source, out);
+  }
+}