From 5d9213a0e9e7686c394385ed50f586b90e0dd6a8 Mon Sep 17 00:00:00 2001
From: ntohidi <nasrin@kidocode.com>
Date: Thu, 12 Jun 2025 12:21:40 +0200
Subject: [PATCH] fix: Update JavaScript execution in
 AsyncPlaywrightCrawlerStrategy to handle script errors and add basic download
 test case. ref #1215

---
 crawl4ai/async_crawler_strategy.py  | 23 +++++++++++++++++--
 tests/general/test_download_file.py | 34 +++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 tests/general/test_download_file.py

diff --git a/crawl4ai/async_crawler_strategy.py b/crawl4ai/async_crawler_strategy.py
index d349388f..c0bf6ec5 100644
--- a/crawl4ai/async_crawler_strategy.py
+++ b/crawl4ai/async_crawler_strategy.py
@@ -1596,12 +1596,31 @@ class AsyncPlaywrightCrawlerStrategy(AsyncCrawlerStrategy):
                     # then wait for the new page to load before continuing
                     result = None
                     try:
+                        # OLD VERSION:
+                        # result = await page.evaluate(
+                        #     f"""
+                        # (async () => {{
+                        #     try {{
+                        #         const script_result = {script};
+                        #         return {{ success: true, result: script_result }};
+                        #     }} catch (err) {{
+                        #         return {{ success: false, error: err.toString(), stack: err.stack }};
+                        #     }}
+                        # }})();
+                        # """
+                        # )
+                        
+                        # """ NEW VERSION:
+                        # When {script} contains statements (e.g., const link = …; link.click();), 
+                        # this forms invalid JavaScript, causing Playwright execution error: SyntaxError: Unexpected token 'const'.
+                        # """
                         result = await page.evaluate(
                             f"""
                         (async () => {{
                             try {{
-                                const script_result = {script};
-                                return {{ success: true, result: script_result }};
+                                return await (async () => {{
+                                    {script}
+                                }})();
                             }} catch (err) {{
                                 return {{ success: false, error: err.toString(), stack: err.stack }};
                             }}
diff --git a/tests/general/test_download_file.py b/tests/general/test_download_file.py
new file mode 100644
index 00000000..ca552779
--- /dev/null
+++ b/tests/general/test_download_file.py
@@ -0,0 +1,34 @@
+import asyncio
+from crawl4ai import CrawlerRunConfig, AsyncWebCrawler, BrowserConfig
+from pathlib import Path
+import os
+
+async def test_basic_download():
+    
+    # Custom folder (otherwise defaults to ~/.crawl4ai/downloads)
+    downloads_path = os.path.join(Path.home(), ".crawl4ai", "downloads")
+    os.makedirs(downloads_path, exist_ok=True)
+    browser_config = BrowserConfig(
+        accept_downloads=True,
+        downloads_path=downloads_path
+    )
+    async with AsyncWebCrawler(config=browser_config) as crawler:
+        run_config = CrawlerRunConfig(
+            js_code="""
+                const link = document.querySelector('a[href$=".exe"]');
+                if (link) { link.click(); }
+            """,
+            delay_before_return_html=5  
+        )
+        result = await crawler.arun("https://www.python.org/downloads/", config=run_config)
+
+        if result.downloaded_files:
+            print("Downloaded files:")
+            for file_path in result.downloaded_files:
+                print("•", file_path)
+        else:
+            print("No files downloaded.")
+
+if __name__ == "__main__":
+    asyncio.run(test_basic_download())
+ 
\ No newline at end of file