feat: support fetching favicon (#1155)

* feat: support fetching favicon

* Update backend/functions/src/dto/scrapping-options.ts

Co-authored-by: Yanlong Wang <yanlong.wang@naiver.org>

* Update backend/functions/src/dto/scrapping-options.ts

Co-authored-by: Yanlong Wang <yanlong.wang@naiver.org>

* chore: remove 'withFavicon' from CrawlerOptions

---------

Co-authored-by: Yanlong Wang <yanlong.wang@naiver.org>

backend/functions/src/cloud-functions/searcher-serper.ts

@@ -92,6 +92,7 @@ export class SearcherHost extends RPCHost {
         // Return content by default
         const respondWith = ctx.req.get('X-Respond-With') ?? 'content';
         const crawlWithoutContent = respondWith.includes('no-content');
+        const withFavicon = ctx.req.get('X-With-Favicons') === 'true';
 
         let chargeAmount = 0;
         const noSlashPath = decodeURIComponent(ctx.req.path).slice(1);
@@ -164,7 +165,7 @@ export class SearcherHost extends RPCHost {
         const targetResultCount = crawlWithoutContent ? count : count + 2;
         const organicSearchResults = r.organic.slice(0, targetResultCount);
         if (crawlWithoutContent || count === 0) {
-            const fakeResults = await this.fakeResult(crawlerOptions.respondWith, organicSearchResults, !crawlWithoutContent);
+            const fakeResults = await this.fakeResult(crawlerOptions, organicSearchResults, !crawlWithoutContent, withFavicon);
             lastScrapped = fakeResults;
             if (!crawlWithoutContent) {
                 chargeAmount = this.assignChargeAmount(lastScrapped);
@@ -181,6 +182,7 @@ export class SearcherHost extends RPCHost {
         const it = this.fetchSearchResults(crawlerOptions.respondWith, r.organic.slice(0, targetResultCount), crawlOpts,
             CrawlerOptions.from({ ...crawlerOptions, cacheTolerance: crawlerOptions.cacheTolerance ?? this.pageCacheToleranceMs }),
             count,
+            withFavicon
         );
 
         if (!ctx.req.accepts('text/plain') && ctx.req.accepts('text/event-stream')) {
@@ -328,10 +330,13 @@ export class SearcherHost extends RPCHost {
     }
 
     async fakeResult(
-        mode: string | 'markdown' | 'html' | 'text' | 'screenshot',
+        crawlerOptions: CrawlerOptions,
         searchResults?: SerperSearchResponse['organic'],
-        withContent: boolean = false
+        withContent: boolean = false,
+        withFavicon: boolean = false,
     ) {
+        const mode: string | 'markdown' | 'html' | 'text' | 'screenshot' = crawlerOptions.respondWith;
+
         if (!searchResults) {
             return [];
         }
@@ -352,7 +357,8 @@ export class SearcherHost extends RPCHost {
             if (withContent) {
                 result.content = ['html', 'text', 'screenshot'].includes(mode) ? undefined : '';
             }
-            if (mode.includes('no-content')) {
+
+            if (withFavicon) {
                 const url = new URL(upstreamSearchResult.link);
                 result.favicon = await this.getFavicon(url.origin);
                 dataItems.push({
@@ -381,6 +387,7 @@ export class SearcherHost extends RPCHost {
         options?: ExtraScrappingOptions,
         crawlerOptions?: CrawlerOptions,
         count?: number,
+        withFavicon?: boolean,
     ) {
         if (!searchResults) {
             return;
@@ -391,9 +398,11 @@ export class SearcherHost extends RPCHost {
         for await (const scrapped of this.crawler.scrapMany(urls, options, crawlerOptions)) {
             const mapped = scrapped.map((x, i) => {
                 const upstreamSearchResult = searchResults[i];
+                const url = upstreamSearchResult.link;
+
                 if (!x) {
                     return {
-                        url: upstreamSearchResult.link,
+                        url,
                         title: upstreamSearchResult.title,
                         description: upstreamSearchResult.snippet,
                         content: ['html', 'text', 'screenshot'].includes(mode) ? undefined : ''
@@ -412,12 +421,19 @@ export class SearcherHost extends RPCHost {
                     this.logger.error(`Failed to format snapshot for ${urls[i].href}`, { err: marshalErrorLike(err) });
 
                     return {
-                        url: upstreamSearchResult.link,
+                        url,
                         title: upstreamSearchResult.title,
                         description: upstreamSearchResult.snippet,
                         content: x.text,
                     };
                 });
+            }).map(async (x) => {
+                const page = await x;
+                if (withFavicon && page.url) {
+                    const url = new URL(page.url);
+                    page.favicon = await this.getFavicon(url.origin);
+                }
+                return page;
             });
 
             const resultArray = await Promise.all(mapped) as FormattedPage[];
@@ -448,11 +464,11 @@ export class SearcherHost extends RPCHost {
                             const textRep = x.textRepresentation ? `\n[${i + 1}] Content: \n${x.textRepresentation}` : '';
                             return `[${i + 1}] Title: ${this.title}
 [${i + 1}] URL Source: ${this.url}
-[${i + 1}] Description: ${this.description}${textRep}
+[${i + 1}] Description: ${this.description}${textRep}${this.favicon !== undefined ? `\n[${i + 1}] Favicon: ${this.favicon}` : ''}
 `;
                         }
 
-                        return `[${i + 1}] No content available for ${this.url}`;
+                        return `[${i + 1}] No content available for ${this.url}${this.favicon !== undefined ? `\n[${i + 1}] Favicon: ${this.favicon}` : ''}`;
                     }
 
                     const mixins = [];
@@ -486,7 +502,7 @@ export class SearcherHost extends RPCHost {
                     }
 
                     return `[${i + 1}] Title: ${this.title}
-[${i + 1}] URL Source: ${this.url}${mixins.length ? `\n${mixins.join('\n')}` : ''}
+[${i + 1}] URL Source: ${this.url}${mixins.length ? `\n${mixins.join('\n')}` : ''}${this.favicon !== undefined ? `\n[${i + 1}] Favicon: ${this.favicon}` : ''}
 [${i + 1}] Markdown Content:
 ${this.content}
 ${suffixMixins.length ? `\n${suffixMixins.join('\n')}\n` : ''}`;