Add other newsletter handlers

packages/content-handler/src/newsletters/substack-handler.ts

@@ -1,10 +1,10 @@
 import addressparser from 'addressparser'
 import { ContentHandler, PreHandleResult } from '../content-handler'
+import { parseHTML } from 'linkedom'
 
 export class SubstackHandler extends ContentHandler {
   constructor() {
     super()
-    this.defaultUrl = 'https://www.substack.com'
     this.name = 'substack'
   }
 
@@ -38,15 +38,53 @@ export class SubstackHandler extends ContentHandler {
     return Promise.resolve(dom)
   }
 
-  isNewsletter(postHeader: string, from: string, unSubHeader: string): boolean {
-    return !!postHeader
+  findNewsletterHeaderHref(dom: Document): string | undefined {
+    // Substack header links
+    const postLink = dom.querySelector('h1 a ')
+    if (postLink) {
+      return postLink.getAttribute('href') || undefined
+    }
+
+    return undefined
   }
 
-  parseNewsletterUrl(postHeader: string, html: string): string | undefined {
+  async isNewsletter({
+    postHeader,
+    html,
+  }: {
+    postHeader: string
+    from: string
+    unSubHeader: string
+    html: string
+  }): Promise<boolean> {
+    if (postHeader) {
+      return Promise.resolve(true)
+    }
+    const dom = parseHTML(html).document
+    // substack newsletter emails have tables with a *post-meta class
+    if (dom.querySelector('table[class$="post-meta"]')) {
+      return true
+    }
+    // If the article has a header link, and substack icons its probably a newsletter
+    const href = this.findNewsletterHeaderHref(dom)
+    const heartIcon = dom.querySelector(
+      'table tbody td span a img[src*="HeartIcon"]'
+    )
+    const recommendIcon = dom.querySelector(
+      'table tbody td span a img[src*="RecommendIconRounded"]'
+    )
+    return Promise.resolve(!!(href && (heartIcon || recommendIcon)))
+  }
+
+  async parseNewsletterUrl(
+    postHeader: string,
+    html: string
+  ): Promise<string | undefined> {
     // raw SubStack newsletter url is like <https://hongbo130.substack.com/p/tldr>
     // we need to get the real url from the raw url
-    return addressparser(postHeader).length > 0
-      ? addressparser(postHeader)[0].name
-      : undefined
+    if (postHeader && addressparser(postHeader).length > 0) {
+      return Promise.resolve(addressparser(postHeader)[0].name)
+    }
+    return this.findNewsletterUrl(html)
   }
 }