Add template support for the message option (#175)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

index.js

@@ -15,6 +15,7 @@ const hasYarn = importLazy('has-yarn');
 const boxen = importLazy('boxen');
 const xdgBasedir = importLazy('xdg-basedir');
 const isCi = importLazy('is-ci');
+const pupa = importLazy('pupa');
 
 const ONE_DAY = 1000 * 60 * 60 * 24;
 
@@ -134,8 +135,13 @@ class UpdateNotifier {
 			installCommand = `npm i ${this.packageName}`;
 		}
 
-		options.message = options.message || 'Update available ' + chalk().dim(this.update.current) + chalk().reset(' → ') +
-			chalk().green(this.update.latest) + ' \nRun ' + chalk().cyan(installCommand) + ' to update';
+		const defaultTemplate = 'Update available ' +
+			chalk().dim('{currentVersion}') +
+			chalk().reset(' → ') +
+			chalk().green('{latestVersion}') +
+			' \nRun ' + chalk().cyan('{updateCommand}') + ' to update';
+
+		const template = options.message || defaultTemplate;
 
 		options.boxenOptions = options.boxenOptions || {
 			padding: 1,
@@ -145,7 +151,15 @@ class UpdateNotifier {
 			borderStyle: 'round'
 		};
 
-		const message = '\n' + boxen()(options.message, options.boxenOptions);
+		const message = '\n' + boxen()(
+			pupa()(template, {
+				packageName: this.packageName,
+				currentVersion: this.update.current,
+				latestVersion: this.update.latest,
+				updateCommand: installCommand
+			}),
+			options.boxenOptions
+		);
 
 		if (options.defer === false) {
 			console.error(message);

package.json

@@ -44,6 +44,7 @@
 		"is-npm": "^4.0.0",
 		"is-yarn-global": "^0.3.0",
 		"latest-version": "^5.0.0",
+		"pupa": "^2.0.1",
 		"semver-diff": "^3.1.1",
 		"xdg-basedir": "^4.0.0"
 	},

readme.md

@@ -156,6 +156,20 @@ Default: [See above screenshot](https://github.com/yeoman/update-notifier#update
 
 Message that will be shown when an update is available.
 
+Available placeholders:
+
+- `{packageName}` - Package name.
+- `{currentVersion}` - Current version.
+- `{latestVersion}` - Latest version.
+- `{updateCommand}` - Update command.
+
+```js
+notifier.notify({message: 'Run `{updateCommand}` to update.'});
+
+// Output:
+// Run `npm install update-notifier-tester@1.0.0` to update.
+```
+
 ##### isGlobal
 
 Type: `boolean`\

test/notify.js

@@ -58,6 +58,44 @@ test('use pretty boxen message by default', t => {
 `);
 });
 
+test('supports custom message', t => {
+	const notifier = new Control();
+	notifier.notify({
+		defer: false,
+		isGlobal: true,
+		message: 'custom message'
+	});
+
+	t.true(stripAnsi(errorLogs).includes('custom message'));
+});
+
+test('supports message with placeholders', t => {
+	const notifier = new Control();
+	notifier.notify({
+		defer: false,
+		isGlobal: true,
+		message: [
+			'Package Name: {packageName}',
+			'Current Version: {currentVersion}',
+			'Latest Version: {latestVersion}',
+			'Update Command: {updateCommand}'
+		].join('\n')
+	});
+
+	t.is(stripAnsi(errorLogs), `
+
+   ╭─────────────────────────────────────────────────────╮
+   │                                                     │
+   │        Package Name: update-notifier-tester         │
+   │               Current Version: 0.0.2                │
+   │                Latest Version: 1.0.0                │
+   │   Update Command: npm i -g update-notifier-tester   │
+   │                                                     │
+   ╰─────────────────────────────────────────────────────╯
+
+`);
+});
+
 test('exclude -g argument when `isGlobal` option is `false`', t => {
 	const notifier = new Control();
 	notifier.notify({defer: false, isGlobal: false});
@@ -77,7 +115,7 @@ test('suppress output when running as npm script', t => {
 	t.false(stripAnsi(errorLogs).includes('Update available'));
 });
 
-test('should ouput if running as npm script and shouldNotifyInNpmScript option set', t => {
+test('should output if running as npm script and shouldNotifyInNpmScript option set', t => {
 	setupTest(true);
 	const notifier = new Control(true);
 	notifier.notify({defer: false});