Add command update.

With the command `onepunch update` the user will update files in the `src` directory according to the latest release of onepunch.
Please note that any custom change inside directory `src` will be overwritten. In order to prevent accidental deletions, the command ckecks the presence of file `onepunch.json`, if the file is not present the command aborts.

Author: riccardoscalco

index.js

@@ -22,13 +22,17 @@ const cli = meow({
 			onepunch print [-i htmlfile] [-o pdffile]
 				Print the presentation in a PDF file.
 
+			onepunch update
+				Update files in the src directory according to the latest release.
+				Please note that any custom change inside directory src will be overwritten
+
 		OPTIONS
 			-n or --name directory_name
 				Specify the name of the directory where the project is initialized. Defaults to onepunch-presentation.
-			
+
 			-i or --input htmlfile
 				Specify the HTML file to print, defaults to "index.html".
-			
+
 			-o or --output pdffile
 				Specify the name of the PDF file in output, defaults to "index.pdf".
 
@@ -67,6 +71,9 @@ switch (cli.input[0]) {
 	case 'print':
 		print(cli.flags);
 		break;
+	case 'update':
+		update();
+		break;
 	default:
 		cli.showHelp();
 		break;
@@ -94,6 +101,20 @@ function init(flags) {
 	fs.copySync(path.resolve(__dirname, 'template'), presentationPath);
 }
 
+function update() {
+	const file = 'onepunch.json';
+
+	if (!fs.existsSync(file)) {
+		abort('File onepunch.json is not present. Are you sure this is the right directory?');
+	}
+
+	fs.copySync(
+		path.resolve(__dirname, 'template/src'),
+		'src',
+		{overwrite: true},
+	);
+}
+
 function print(flags) {
 	const {input, output} = flags;
 

readme.md

@@ -16,6 +16,12 @@ $ npm install -g @nextbitlabs/onepunch
 
 Please note that onepunch makes use of [puppeteer](https://github.com/puppeteer/puppeteer/), which will download chromium. This is necessary to print the PDF file.
 
+Update **onepunch** to the latest release with:
+
+```
+$ npm update -g @nextbitlabs/onepunch
+```
+
 ### Create a project
 
 ```
@@ -42,6 +48,21 @@ Inside the project directory, run:
 $ onepunch print
 ```
 
+### Update
+
+Update files in the `src` directory according to the latest release of **onepunch**, please note that any custom change inside directory `src` will be overwritten:
+
+```
+$ onepunch update
+```
+
+The above command assumes you have installed the latest release of **onepunch**.
+If this is not the case, update **onepunch** to the latest release with:
+
+```
+$ npm update -g @nextbitlabs/onepunch
+```
+
 ### Create custom styles
 
 Each slide is created by means of tag `article`, for example:

template/readme.md

@@ -11,3 +11,9 @@ Print the presentation in a PDF file with:
 ```
 $ onepunch print
 ```
+
+Update files in the `src` directory according to the latest release:
+
+```
+$ onepunch update
+```