Try to auto-detect attachments/downloads for text or HTML Re #3434

changedetectionio/processors/text_json_diff/processor.py

@@ -153,12 +153,26 @@ class perform_site_check(difference_detection_processor):
             # CSS Filter, extract the HTML that matches and feed that into the existing inscriptis::get_text
             self.fetcher.content = html_tools.workarounds_for_obfuscations(self.fetcher.content)
             html_content = self.fetcher.content
+            content_type = self.fetcher.get_all_headers().get('content-type', '').lower()
+            is_attachment = 'attachment' in self.fetcher.get_all_headers().get('content-disposition', '').lower()
 
-            # If not JSON,  and if it's not text/plain..
-            if 'text/plain' in self.fetcher.get_all_headers().get('content-type', '').lower():
+            # Try to detect better mime types if its a download or not announced as HTML
+            if is_attachment or 'octet-stream' in content_type or not 'html' in content_type:
+                logger.debug(f"Got a reply that may be a download or possibly a text attachment, checking..")
+                try:
+                    import magic
+                    mime = magic.from_buffer(html_content, mime=True)
+                    logger.debug(f"Guessing mime type, original content_type '{content_type}', mime type detected '{mime}'")
+                    if mime and "/" in mime: # looks valid and is a valid mime type
+                        content_type = mime
+                except Exception as e:
+                    logger.error(f"Error getting a more precise mime type from 'magic' library ({str(e)}")
+
+            if 'text/' in content_type and not 'html' in content_type:
                 # Don't run get_text or xpath/css filters on plaintext
                 stripped_text_from_html = html_content
             else:
+                # If not JSON, and if it's not text/plain..
                 # Does it have some ld+json price data? used for easier monitoring
                 update_obj['has_ldjson_price_data'] = html_tools.has_ldjson_product_info(self.fetcher.content)
 

changedetectionio/tests/test_backend.py

@@ -165,3 +165,53 @@ def test_check_basic_change_detection_functionality(client, live_server, measure
     # Cleanup everything
     res = client.get(url_for("ui.form_delete", uuid="all"), follow_redirects=True)
     assert b'Deleted' in res.data
+
+def test_non_text_mime_or_downloads(client, live_server, measure_memory_usage):
+    with open("test-datastore/endpoint-content.txt", "w") as f:
+        f.write("""some random text that should be split by line
+and not parsed with html_to_text
+this way we know that it correctly parsed as plain text
+\r\n
+ok\r\n
+got it\r\n
+""")
+
+    test_url = url_for('test_endpoint', content_type="application/octet-stream", _external=True)
+
+    # Add our URL to the import page
+    res = client.post(
+        url_for("imports.import_page"),
+        data={"urls": test_url},
+        follow_redirects=True
+    )
+
+    assert b"1 Imported" in res.data
+
+    wait_for_all_checks(client)
+
+    ### check the front end
+    res = client.get(
+        url_for("ui.ui_views.preview_page", uuid="first"),
+        follow_redirects=True
+    )
+    assert b"some random text that should be split by line\n" in res.data
+    ####
+
+    # Check the snapshot by API that it has linefeeds too
+    watch_uuid = next(iter(live_server.app.config['DATASTORE'].data['watching']))
+    api_key = live_server.app.config['DATASTORE'].data['settings']['application'].get('api_access_token')
+    res = client.get(
+        url_for("watchhistory", uuid=watch_uuid),
+        headers={'x-api-key': api_key},
+    )
+
+    # Fetch a snapshot by timestamp, check the right one was found
+    res = client.get(
+        url_for("watchsinglehistory", uuid=watch_uuid, timestamp=list(res.json.keys())[-1]),
+        headers={'x-api-key': api_key},
+    )
+    assert b"some random text that should be split by line\n" in res.data
+
+
+    res = client.get(url_for("ui.form_delete", uuid="all"), follow_redirects=True)
+