add optional language field

README.md

@@ -32,6 +32,7 @@ const feed = new Feed({
   description: "This is my personal feed!",
   id: "http://example.com/",
   link: "http://example.com/",
+  language: "en", // optional, used only in RSS 2.0, possible values: http://www.w3.org/TR/REC-html40/struct/dirlang.html#langcodes
   image: "http://example.com/image.png",
   favicon: "http://example.com/favicon.ico",
   copyright: "All rights reserved 2013, John Doe",

src/__tests__/__snapshots__/rss2.spec.ts.snap

@@ -10,6 +10,7 @@ exports[`rss 2.0 should generate a valid feed 1`] = `
         <lastBuildDate>Sat, 13 Jul 2013 23:00:00 GMT</lastBuildDate>
         <docs>http://blogs.law.harvard.edu/tech/rss</docs>
         <generator>https://github.com/jpmonette/feed</generator>
+        <language>en</language>
         <image>
             <title>Feed Title</title>
             <url>http://example.com/image.png</url>

src/__tests__/setup.ts

@@ -9,6 +9,7 @@ export const sampleFeed = new Feed({
   link: "http://example.com/",
   id: "http://example.com/",
   feed: "http://example.com/sampleFeed.rss",
+  language: "en",
   image: "http://example.com/image.png",
   copyright: "All rights reserved 2013, John Doe",
   updated, // optional, default = today

src/rss2.ts

@@ -24,6 +24,16 @@ export default (ins: Feed) => {
 
   const rss: any[] = [{ _attr: { version: "2.0" } }, { channel }];
 
+  /**
+   * Channel language
+   * https://validator.w3.org/feed/docs/rss2.html#ltimagegtSubelementOfLtchannelgt
+   */
+  if (options.language) {
+    channel.push({
+      language: options.language
+    });
+  }
+
   /**
    * Channel Image
    * http://cyber.law.harvard.edu/rss/rss.html#ltimagegtSubelementOfLtchannelgt

src/types/index.ts

@@ -31,6 +31,7 @@ interface FeedOptions {
   title: string;
   updated?: Date;
   generator?: string;
+  language?: string;
 
   feed?: string;
   feedLinks: any;