feat(contributor-workflow): add command to copy vendored PUI packages…

… to projects

- See contributing guidelines for details

[Finishes #95551932]

CONTRIBUTING.md

@@ -148,6 +148,25 @@ This will ensure our conversation doesn't get lost in email or slack.
    git push -f origin head
    ```
 
+1. While you're waiting for your PR to be accepted, you can use your forked
+   changes in your project. For example, if you made changes to the react alerts
+   component, run the following command:
+
+   ```bash
+   gulp vendor-package --type=react --component=alerts --dest=<your-project-folder>
+   ```
+
+   Similarly, if you made changes to the CSS typography component, run
+
+   ```bash
+   gulp vendor-package --type=css --component=typography --dest=<your-project-folder>
+   ```
+
+   This creates a vendored version of your modified components
+   (`pui-react-alerts` or `pui-css-typography`) in your project, and points your
+   project's package json to these vendored versions. This way, you can use your
+   forked changes right away, even in production!
+
 1. Once we accept your pull request, we will publish any new or updated pacakges
    to NPM.
 

tasks/vendor-package.js

@@ -0,0 +1,26 @@
+import {exec} from 'child_process';
+import gulp from 'gulp';
+import path from 'path';
+import {argv} from 'yargs';
+
+gulp.task('vendor-package', ['css-build', 'react-build'], (callback) => {
+  const {type: componentType, component: componentName, dest} = argv;
+
+  function useVendoredPackageInProject() {
+    console.log('hi');
+    const originalDirectory = process.cwd();
+    process.chdir(dest);
+
+    exec(`npm install --save ${path.join('pui-vendor', componentType, componentName)}`, (error) => {
+      if (error) {
+        new gutil.PluginError('vendor-package', {message: error});
+      }
+      process.chdir(originalDirectory);
+      callback();
+    });
+  }
+
+  gulp.src(`dist/${componentType}/${componentName}/*`)
+    .pipe(gulp.dest(`${dest}/pui-vendor/${componentType}/${componentName}`))
+    .on('end', useVendoredPackageInProject);
+});