refactor(scraper): make get_register_link and get_user_credit dump on failure

app/cm_bot.py

@@ -452,8 +452,21 @@ class CM_BOT:
     def get_register_link(self):
         response = self.session.get(f"{self.base_url}/cm/showQrCode")
         soup = BeautifulSoup(response.content, 'html.parser')
-        soup = soup.find('form', {'id': 'qrCodeForm'})
-        return soup.find('a')['href']
+        form = soup.find('form', {'id': 'qrCodeForm'})
+        if form is None:
+            path = self._dump_html("register_link_form", response.content)
+            raise ScraperError(
+                f"register_link: form#qrCodeForm not found "
+                f"(response saved to {path})"
+            )
+        anchor = form.find('a')
+        if anchor is None or 'href' not in anchor.attrs:
+            path = self._dump_html("register_link_anchor", response.content)
+            raise ScraperError(
+                f"register_link: <a href> inside form#qrCodeForm not found "
+                f"(response saved to {path})"
+            )
+        return anchor['href']
 
     def get_generate_username(self, max_username_index: int):
         max_username_index += 1
@@ -515,11 +528,9 @@ class CM_BOT:
         soup = BeautifulSoup(response.content, 'html.parser')
         try:
             return round(float(soup.find('table', {'class': 'generalContent'}).find(text=re.compile('Credit Available')).parent.parent.find_all('td')[2].text.replace(",","")), 2)
-        except:
-            print(f"Error getting credit.")
-            now = datetime.datetime.now().strftime('%Y%m%d_%H%M')
-            # with open(f'credit-{now}.html', 'wb') as f:
-            #     f.write(response.content)
+        except Exception as exc:
+            self._dump_html("get_user_credit", response.content)
+            print(f"Error getting credit: {exc}")
             return 0
 
     def get_transfer_token(self):