apply feedback

  - add some documentation
  - wording
  - remove dead code, Zenpy doens't raise on failed authentication

README.md

@@ -12,6 +12,8 @@ Tap for Zendesk
 
 ### Using OAuth
 
+OAuth is the default authentication method for `tap-zendesk`. To use OAuth, you will need to fetch an `access_token` from a configured Zendesk integration. See https://support.zendesk.com/hc/en-us/articles/203663836 for more details on how to integrate your application with Zendesk.
+
 **config.json**
 ```json
 {
@@ -23,7 +25,7 @@ Tap for Zendesk
 
 ### Using API Tokens
 
-Use the following configuration:
+For a simplified, but less granular setup, you can use the API Token authentication which can be generated from the Zendesk Admin page. See https://support.zendesk.com/hc/en-us/articles/226022787-Generating-a-new-API-token- for more details about generating an API Token. You'll then be able to use the admins's `email` and the generated `api_token` to authenticate.
 
 **config.json**
 ```json

tap_zendesk/__init__.py

@@ -16,15 +16,16 @@
     "subdomain",
 ]
 
-API_CONFIG_KEYS = REQUIRED_CONFIG_KEYS + [
-    "email",
-    "api_token",
-]
-
-OAUTH_CONFIG_KEYS = REQUIRED_CONFIG_KEYS + [
+# default authentication
+OAUTH_CONFIG_KEYS = [
     "access_token",
 ]
 
+# email + api_token authentication
+API_TOKEN_CONFIG_KEYS = [
+    "email",
+    "api_token",
+]
 
 def do_discover(client):
     LOGGER.info("Starting discover")
@@ -126,43 +127,46 @@ def do_sync(client, catalog, state, start_date):
     singer.write_state(state)
     LOGGER.info("Finished sync")
 
-def oauth_auth():
-    try:
-        oauth_args = singer.utils.parse_args(OAUTH_CONFIG_KEYS)
-        creds = {
-            "subdomain": args['subdomain'],
-            "oauth_token": oauth_args.config['access_token'],
-        }
-
-        client = Zenpy(**creds)
-        LOGGER.info("OAuth authentication successful.")
-        return client
-    except ZenpyException:
-        LOGGER.error("OAuth authentication failed.")
-    except Exception:
-        LOGGER.error("Cannot find OAuth configuration.")
-
-def api_token_auth():
-    try:
-        api_args = singer.utils.parse_args(API_CONFIG_KEYS)
-        creds = {
-            "subdomain": api_args.config['subdomain'],
-            "email": api_args.config['email'],
-            "token": api_args.config['api_token']
-        }
-
-        client = Zenpy(**creds)
-        LOGGER.info("API Token authentication successful.")
-        return client
-    except ZenpyException:
-        LOGGER.error("API Token authentication failed.")
-    except Exception:
-        LOGGER.error("Cannot find API Token configuration.")
+def oauth_auth(args):
+    if not set(OAUTH_CONFIG_KEYS).issubset(args.config.keys()):
+        LOGGER.debug("OAuth authentication unavailable.")
+        return None
+
+    creds = {
+        "subdomain": args.config['subdomain'],
+        "oauth_token": args.config['access_token'],
+    }
+
+    client = Zenpy(**creds)
+    LOGGER.info("Using OAuth authentication.")
+    return client
+
+def api_token_auth(args):
+    if not set(API_TOKEN_CONFIG_KEYS).issubset(args.config.keys()):
+        LOGGER.debug("API Token authentication unavailable.")
+        return None
+
+    creds = {
+        "subdomain": args.config['subdomain'],
+        "email": args.config['email'],
+        "token": args.config['api_token']
+    }
+
+    client = Zenpy(**creds)
+    LOGGER.info("Using API Token authentication.")
+    return client
 
 @singer.utils.handle_top_exception(LOGGER)
 def main():
     parsed_args = singer.utils.parse_args(REQUIRED_CONFIG_KEYS)
-    client = oauth_auth() or api_token_auth()
+
+    # OAuth has precedence
+    client = oauth_auth(parsed_args) or api_token_auth(parsed_args)
+
+    if not client:
+        LOGGER.error("""No suitable authentication keys provided.
+  OAuth:\t\taccess_token
+  API Token:\t\temail, api_token""")
 
     if parsed_args.discover:
         do_discover(client)