feat(fetch-favicon): add favicon fetch CLI

.changeset/fuzzy-kids-repair.md

@@ -0,0 +1,6 @@
+---
+'@patricktree/fetch-favicon': minor
+---
+
+- add a fetch-favicon CLI for batch URL input
+- keep fetching other favicons when one fails, with clearer source logging

packages/fetch-favicon/package.json

@@ -45,8 +45,10 @@
     "turbo:lint:fix": "pnpm run lint:file . --fix"
   },
   "dependencies": {
+    "@commander-js/extra-typings": "^14.0.0",
     "@patricktree/commons-ecma": "workspace:^",
     "@patricktree/commons-node": "workspace:^",
+    "commander": "^14.0.2",
     "tiny-invariant": "^1.3.3",
     "zod": "^3.23.8"
   },

packages/fetch-favicon/src/fetch-favicon-cli.ts

@@ -0,0 +1,45 @@
+#!/usr/bin/env node
+/* eslint-disable n/no-process-exit -- is a CLI */
+
+import * as commander from '@commander-js/extra-typings';
+import { writeFile } from 'node:fs/promises';
+
+import { fetchFavicons } from '#pkg/index.js';
+
+const program = new commander.Command()
+  .name('fetch-favicon')
+  .addArgument(new commander.Argument('[url...]'))
+  .addOption(new commander.Option('-o, --output <path>', 'Write JSON output to a file'))
+  .addOption(new commander.Option('--stdin', 'Read URLs from stdin (whitespace-separated)'))
+  .addOption(new commander.Option('--no-pretty', 'Minify JSON output'));
+
+program.parse();
+
+const options = program.opts();
+const hrefs = program.processedArgs[0];
+const shouldReadStdin = options.stdin || (!process.stdin.isTTY && hrefs.length === 0);
+const stdinUrls = shouldReadStdin ? await readStdinUrls() : [];
+const uniqueHrefs = [...new Set([...hrefs, ...stdinUrls])];
+
+if (uniqueHrefs.length === 0) {
+  program.outputHelp();
+  process.exit(1);
+}
+
+const normalizedHrefs = uniqueHrefs.map((href) => new URL(href).href);
+const result = await fetchFavicons(normalizedHrefs);
+const json = JSON.stringify(result, null, options.pretty ? 2 : 0);
+
+if (options.output) {
+  await writeFile(options.output, `${json}\n`, 'utf8');
+} else {
+  console.log(json);
+}
+
+async function readStdinUrls(): Promise<string[]> {
+  const chunks: string[] = [];
+  for await (const chunk of process.stdin) {
+    chunks.push(String(chunk));
+  }
+  return chunks.join('').split(/\s+/).filter(Boolean);
+}

packages/fetch-favicon/src/index.ts

@@ -2,7 +2,6 @@ import playwright from 'playwright';
 import invariant from 'tiny-invariant';
 import { z } from 'zod';
 
-import { arrays } from '@patricktree/commons-ecma/util/arrays';
 import { check } from '@patricktree/commons-ecma/util/assert';
 import { binaryUtils } from '@patricktree/commons-node/utils/binary';
 
@@ -45,29 +44,39 @@ export async function fetchFavicons(hrefs: string[]): Promise<FaviconsForWebsite
   }
 
   console.log('Step #2: Gather a list of favicon URLs we need to fetch (with duplicates removed)');
-  let allIconURLs: URL[] = [];
-  for (const entry of Object.values(websites)) {
+  const allIconURLs: Array<{ url: URL; sources: Set<string> }> = [];
+  function addIconTarget(iconURL: string, websiteHref: string) {
+    const existing = allIconURLs.find((entry) => entry.url.href === iconURL);
+    if (existing) {
+      existing.sources.add(websiteHref);
+      return;
+    }
+    allIconURLs.push({ url: new URL(iconURL), sources: new Set([websiteHref]) });
+  }
+  for (const [websiteHref, entry] of Object.entries(websites)) {
     invariant(entry);
     if (check.isNonEmptyString(entry.iconURLs.light)) {
-      allIconURLs.push(new URL(entry.iconURLs.light));
+      addIconTarget(entry.iconURLs.light, websiteHref);
     }
     if (check.isNonEmptyString(entry.iconURLs.dark)) {
-      allIconURLs.push(new URL(entry.iconURLs.dark));
+      addIconTarget(entry.iconURLs.dark, websiteHref);
     }
   }
-  allIconURLs = arrays.uniqueValues(allIconURLs);
 
   console.log('Step #3: Go to every favicon URL and store the favicon as a data URL');
   const icons: FaviconsForWebsites['icons'] = {};
-  await Promise.all(
-    allIconURLs.map(async (url) => {
-      console.log(`Fetching favicon from ${url.href}`);
+  for (const { url, sources } of allIconURLs) {
+    console.log(`Fetching favicon from ${url.href}`);
+    try {
       const response = await fetchUrl(url);
       const blob = await response.blob();
       const dataURL = await binaryUtils.convertBlobToDataURL(blob);
       icons[url.href] = { dataURL };
-    }),
-  );
+    } catch (error) {
+      const sourcesText = [...sources].join(', ');
+      console.error(`Failed to fetch favicon from ${url.href} (source: ${sourcesText})`, error);
+    }
+  }
 
   console.log('Step #4: Close the puppeteer browser');
   await browser.close();