feat(atom/rss/json): support language and on feed and feed items (#196)

src/__tests__/__snapshots__/atom1.spec.ts.snap

@@ -2,7 +2,7 @@
 
 exports[`atom 1.0 should generate a valid feed 1`] = `
 "<?xml version=\\"1.0\\" encoding=\\"utf-8\\"?>
-<feed xmlns=\\"http://www.w3.org/2005/Atom\\">
+<feed xmlns=\\"http://www.w3.org/2005/Atom\\" xml:lang=\\"en\\">
     <id>http://example.com/?link=sanitized&amp;value=4</id>
     <title>Feed Title</title>
     <updated>2013-07-13T23:00:00.000Z</updated>

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

@@ -2,11 +2,12 @@
 
 exports[`json 1 should generate a valid feed 1`] = `
 "{
-    \\"version\\": \\"https://jsonfeed.org/version/1\\",
+    \\"version\\": \\"https://jsonfeed.org/version/1.1\\",
     \\"title\\": \\"Feed Title\\",
     \\"home_page_url\\": \\"http://example.com/?link=sanitized&value=3\\",
     \\"feed_url\\": \\"http://example.com/sampleFeed.json?link=sanitized&value=5\\",
     \\"description\\": \\"This is my personnal feed!\\",
+    \\"language\\": \\"en\\",
     \\"icon\\": \\"http://example.com/image.png?link=sanitized&value=6\\",
     \\"author\\": {
         \\"name\\": \\"John Doe\\",

src/__tests__/atom1.language.test.ts

@@ -0,0 +1,135 @@
+import { Feed } from "../feed";
+
+describe("atom 1.0 language support", () => {
+  it("should generate a feed with xml:lang attribute when language is specified", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "de-DE",
+      copyright: "Test Copyright",
+    });
+
+    const actual = feed.atom1();
+    expect(actual).toContain('xml:lang="de-DE"');
+    expect(actual).toContain('<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="de-DE">');
+  });
+
+  it("should generate a feed without xml:lang attribute when language is not specified", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      copyright: "Test Copyright",
+    });
+
+    const actual = feed.atom1();
+    expect(actual).not.toContain("xml:lang");
+    expect(actual).toContain('<feed xmlns="http://www.w3.org/2005/Atom">');
+  });
+
+  it("should handle different language codes correctly", () => {
+    const testCases = ["en", "fr", "es-ES", "zh-CN", "ja-JP", "pt-BR"];
+
+    testCases.forEach((language) => {
+      const feed = new Feed({
+        title: "Test Feed",
+        description: "Test Description",
+        link: "http://example.com",
+        id: "http://example.com",
+        language,
+        copyright: "Test Copyright",
+      });
+
+      const actual = feed.atom1();
+      expect(actual).toContain(`xml:lang="${language}"`);
+    });
+  });
+
+  it("should sanitize language attribute like other attributes", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "en&test=malicious",
+      copyright: "Test Copyright",
+    });
+
+    const actual = feed.atom1();
+    // The language should be sanitized to prevent XML injection
+    expect(actual).toContain('xml:lang="en&amp;test=malicious"');
+    // Verify the XML is still valid by checking the structure
+    expect(actual).toContain('<feed xmlns="http://www.w3.org/2005/Atom"');
+  });
+
+  it("should support per-item language attributes", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "en",
+      copyright: "Test Copyright",
+    });
+
+    feed.addItem({
+      title: "Article in English",
+      link: "http://example.com/english",
+      date: new Date("2023-01-01"),
+    });
+
+    feed.addItem({
+      title: "Article en Français",
+      link: "http://example.com/french",
+      date: new Date("2023-01-02"),
+      language: "fr-FR",
+    });
+
+    feed.addItem({
+      title: "Artículo en Español",
+      link: "http://example.com/spanish",
+      date: new Date("2023-01-03"),
+      language: "es-ES",
+    });
+
+    const actual = feed.atom1();
+
+    // Feed should have default language
+    expect(actual).toContain('<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">');
+
+    // First entry should not have xml:lang (inherits from feed)
+    const firstEntryMatch = actual.match(/<entry>\s*<title[^>]*><!\[CDATA\[Article in English\]\]><\/title>/);
+    expect(firstEntryMatch).toBeTruthy();
+
+    // Second entry should have French language
+    expect(actual).toContain('<entry xml:lang="fr-FR">');
+    expect(actual).toContain("<![CDATA[Article en Français]]>");
+
+    // Third entry should have Spanish language
+    expect(actual).toContain('<entry xml:lang="es-ES">');
+    expect(actual).toContain("<![CDATA[Artículo en Español]]>");
+  });
+
+  it("should sanitize per-item language attributes", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      copyright: "Test Copyright",
+    });
+
+    feed.addItem({
+      title: "Test Article",
+      link: "http://example.com/test",
+      date: new Date("2023-01-01"),
+      language: "fr&malicious=code",
+    });
+
+    const actual = feed.atom1();
+    expect(actual).toContain('<entry xml:lang="fr&amp;malicious=code">');
+  });
+});

src/__tests__/json.language.test.ts

@@ -0,0 +1,115 @@
+import { Feed } from "../feed";
+
+describe("json feed language support", () => {
+  it("should generate a feed with language when specified", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "fr-FR",
+      copyright: "Test Copyright",
+    });
+
+    const actual = JSON.parse(feed.json1());
+    expect(actual.language).toBe("fr-FR");
+    expect(actual.version).toBe("https://jsonfeed.org/version/1.1");
+  });
+
+  it("should generate a feed without language when not specified", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      copyright: "Test Copyright",
+    });
+
+    const actual = JSON.parse(feed.json1());
+    expect(actual.language).toBeUndefined();
+    expect(actual.version).toBe("https://jsonfeed.org/version/1.1");
+  });
+
+  it("should handle different language codes correctly", () => {
+    const testCases = ["en", "de", "ja-JP", "zh-CN", "pt-BR", "es-ES"];
+
+    testCases.forEach((language) => {
+      const feed = new Feed({
+        title: "Test Feed",
+        description: "Test Description",
+        link: "http://example.com",
+        id: "http://example.com",
+        language,
+        copyright: "Test Copyright",
+      });
+
+      const actual = JSON.parse(feed.json1());
+      expect(actual.language).toBe(language);
+    });
+  });
+
+  it("should support per-item language", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "en",
+      copyright: "Test Copyright",
+    });
+
+    feed.addItem({
+      title: "Article in English",
+      link: "http://example.com/english",
+      date: new Date("2023-01-01"),
+    });
+
+    feed.addItem({
+      title: "Article en Français",
+      link: "http://example.com/french",
+      date: new Date("2023-01-02"),
+      language: "fr-FR",
+    });
+
+    feed.addItem({
+      title: "Artículo en Español",
+      link: "http://example.com/spanish",
+      date: new Date("2023-01-03"),
+      language: "es-ES",
+    });
+
+    const actual = JSON.parse(feed.json1());
+
+    // Feed should have default language
+    expect(actual.language).toBe("en");
+
+    // Check items
+    expect(actual.items).toHaveLength(3);
+
+    // First item should not have language (inherits from feed)
+    expect(actual.items[0].language).toBeUndefined();
+    expect(actual.items[0].title).toBe("Article in English");
+
+    // Second item should have French language
+    expect(actual.items[1].language).toBe("fr-FR");
+    expect(actual.items[1].title).toBe("Article en Français");
+
+    // Third item should have Spanish language
+    expect(actual.items[2].language).toBe("es-ES");
+    expect(actual.items[2].title).toBe("Artículo en Español");
+  });
+
+  it("should handle special characters in language codes", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "zh-Hans-CN", // Traditional Chinese (Simplified) in China
+      copyright: "Test Copyright",
+    });
+
+    const actual = JSON.parse(feed.json1());
+    expect(actual.language).toBe("zh-Hans-CN");
+  });
+});

src/__tests__/rss2.language.test.ts

@@ -0,0 +1,84 @@
+import { Feed } from "../feed";
+
+describe("rss2 language support", () => {
+  it("should generate a feed with language element when specified", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "de-DE",
+      copyright: "Test Copyright",
+    });
+
+    const actual = feed.rss2();
+    expect(actual).toContain("<language>de-DE</language>");
+  });
+
+  it("should generate a feed without language element when not specified", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      copyright: "Test Copyright",
+    });
+
+    const actual = feed.rss2();
+    expect(actual).not.toContain("<language>");
+  });
+
+  it("should handle different language codes correctly", () => {
+    const testCases = ["en", "fr", "es-ES", "zh-CN", "ja-JP", "pt-BR"];
+
+    testCases.forEach((language) => {
+      const feed = new Feed({
+        title: "Test Feed",
+        description: "Test Description",
+        link: "http://example.com",
+        id: "http://example.com",
+        language,
+        copyright: "Test Copyright",
+      });
+
+      const actual = feed.rss2();
+      expect(actual).toContain(`<language>${language}</language>`);
+    });
+  });
+
+  it("should verify RSS2 does not support per-item language (channel-level only)", () => {
+    const feed = new Feed({
+      title: "Test Feed",
+      description: "Test Description",
+      link: "http://example.com",
+      id: "http://example.com",
+      language: "en",
+      copyright: "Test Copyright",
+    });
+
+    feed.addItem({
+      title: "Article in English",
+      link: "http://example.com/english",
+      date: new Date("2023-01-01"),
+    });
+
+    feed.addItem({
+      title: "Article en Français",
+      link: "http://example.com/french",
+      date: new Date("2023-01-02"),
+      language: "fr-FR", // This should be ignored for RSS2
+    });
+
+    const actual = feed.rss2();
+
+    // Feed should have channel-level language
+    expect(actual).toContain("<language>en</language>");
+
+    // RSS2 does not support per-item language, so items should not have language elements
+    expect(actual).not.toContain("<language>fr-FR</language>");
+
+    // Verify items are present but without language
+    expect(actual).toContain("<![CDATA[Article in English]]>");
+    expect(actual).toContain("<![CDATA[Article en Français]]>");
+  });
+});

src/atom1.ts

@@ -11,10 +11,17 @@ import { sanitize } from "./utils";
 export default (ins: Feed) => {
   const { options } = ins;
 
+  const feedAttrs: Record<string, string> = { xmlns: "http://www.w3.org/2005/Atom" };
+  if (ins.options.language) {
+    // Atom uses the reserved "xml:" namespace for language;
+    // no extra xmlns declaration is required.
+    feedAttrs["xml:lang"] = sanitize(ins.options.language) || ins.options.language;
+  }
+
   const base: any = {
     _declaration: { _attributes: { version: "1.0", encoding: "utf-8" } },
     feed: {
-      _attributes: { xmlns: "http://www.w3.org/2005/Atom" },
+      _attributes: feedAttrs,
       id: options.id,
       title: options.title,
       updated: options.updated ? options.updated.toISOString() : new Date().toISOString(),
@@ -96,6 +103,11 @@ export default (ins: Feed) => {
       updated: item.date.toISOString(),
     };
 
+    // Add xml:lang attribute if language is specified for this item
+    if (item.language) {
+      entry._attributes = { "xml:lang": sanitize(item.language) || item.language };
+    }
+
     //
     // entry: recommended elements
     //