Add distTag option (#151)

index.js

@@ -20,6 +20,7 @@ class UpdateNotifier {
 	constructor(options = {}) {
 		this.options = options;
 		options.pkg = options.pkg || {};
+		options.distTag = options.distTag || 'latest';
 
 		// Reduce pkg to the essential keys. with fallback to deprecated options
 		// TODO: Remove deprecated options at some point far into the future
@@ -106,12 +107,13 @@ class UpdateNotifier {
 	}
 
 	async checkNpm() {
-		const latest = await latestVersion()(this.packageName);
+		const {distTag} = this.options;
+		const latest = await latestVersion()(this.packageName, {version: distTag});
 
 		return {
 			latest,
 			current: this.packageVersion,
-			type: semverDiff()(this.packageVersion, latest) || 'latest',
+			type: semverDiff()(this.packageVersion, latest) || distTag,
 			name: this.packageName
 		};
 	}

readme.md

@@ -137,6 +137,13 @@ Default: `false`
 
 Allows notification to be shown when running as an npm script.
 
+#### distTag
+
+Type: `string`<br>
+Default: `latest`
+
+Which [dist-tag](https://docs.npmjs.com/adding-dist-tags-to-packages) to use to find the latest version.
+
 ### notifier.notify([options])
 
 Convenience method to display a notification message. *(See screenshot)*

test/update-notifier.js

@@ -13,7 +13,8 @@ const generateSettings = (options = {}) => {
 			name: 'update-notifier-tester',
 			version: '0.0.2'
 		},
-		callback: options.callback
+		callback: options.callback,
+		distTag: options.distTag
 	};
 };
 
@@ -35,7 +36,12 @@ test.afterEach(() => {
 
 test('check for update', async t => {
 	const update = await updateNotifier(generateSettings()).checkNpm();
-	t.is(update.current, '0.0.2');
+	t.is(update.latest, '0.0.2');
+});
+
+test('check for update with dist-tag', async t => {
+	const update = await updateNotifier(generateSettings({distTag: '0.0.3-rc1'})).checkNpm();
+	t.is(update.latest, '0.0.3-rc1');
 });
 
 test.cb('check for update with callback', t => {