From a7aa99bfe52be6c6b7c24a05e2db5ea280ec7264 Mon Sep 17 00:00:00 2001
From: Richard O'Dwyer <richard@richard.do>
Date: Wed, 23 Oct 2019 19:52:52 +0100
Subject: [PATCH]  Adds code, message attrs to RequestError exception, makes
 message in raised exceptions include more details.

---
 HISTORY.rst              |  1 +
 src/mega/errors.py       | 78 ++++++++++++++++++++++++++++++++++++++--
 src/tests/test_errors.py | 17 +++++++++
 3 files changed, 94 insertions(+), 2 deletions(-)

diff --git a/HISTORY.rst b/HISTORY.rst
index 0bc68d9..086829d 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -9,6 +9,7 @@ Release History
 - Removes broken method ``get_contacts()``.
 - Adds support for login with a v2 Mega user account.
 - Adds ``export()`` method to share a file or folder, returning public share URL with key.
+- Adds code, message attrs to RequestError exception, makes message in raised exceptions include more details.
 
 
 0.9.20 (2019-10-17)
diff --git a/src/mega/errors.py b/src/mega/errors.py
index d231381..4df7f90 100644
--- a/src/mega/errors.py
+++ b/src/mega/errors.py
@@ -5,9 +5,83 @@ class ValidationError(Exception):
     pass
 
 
+_CODE_TO_DESCRIPTIONS = {
+    -1: (
+        'EINTERNAL',
+        (
+            'An internal error has occurred. Please submit a bug report, '
+            'detailing the exact circumstances in which this error occurred'
+        )
+    ),
+    -2: ('EARGS', 'You have passed invalid arguments to this command'),
+    -3: (
+        'EAGAIN',
+        (
+            '(always at the request level) A temporary congestion or server '
+            'malfunction prevented your request from being processed. '
+            'No data was altered. Retry. Retries must be spaced with '
+            'exponential backoff'
+        )
+    ),
+    -4: (
+        'ERATELIMIT',
+        (
+            'You have exceeded your command weight per time quota. Please '
+            'wait a few seconds, then try again (this should never happen '
+            'in sane real-life applications)'
+        )
+    ),
+    -5: ('EFAILED', 'The upload failed. Please restart it from scratch'),
+    -6: (
+        'ETOOMANY',
+        'Too many concurrent IP addresses are accessing this upload target URL'
+    ),
+    -7: (
+        'ERANGE',
+        (
+            'The upload file packet is out of range or not starting and '
+            'ending on a chunk boundary'
+        )
+    ),
+    -8: (
+        'EEXPIRED',
+        (
+            'The upload target URL you are trying to access has expired. '
+            'Please request a fresh one'
+        )
+    ),
+    -9: ('ENOENT', 'Object (typically, node or user) not found'),
+    -10: ('ECIRCULAR', 'Circular linkage attempted'),
+    -11: (
+        'EACCESS',
+        'Access violation (e.g., trying to write to a read-only share)'
+    ),
+    -12: ('EEXIST', 'Trying to create an object that already exists'),
+    -13: ('EINCOMPLETE', 'Trying to access an incomplete resource'),
+    -14: ('EKEY', 'A decryption operation failed (never returned by the API)'),
+    -15: ('ESID', 'Invalid or expired user session, please relogin'),
+    -16: ('EBLOCKED', 'User blocked'),
+    -17: ('EOVERQUOTA', 'Request over quota'),
+    -18: (
+        'ETEMPUNAVAIL',
+        'Resource temporarily not available, please try again later'
+    ),
+    -19: ('ETOOMANYCONNECTIONS', 'many connections on this resource'),
+    -20: ('EWRITE', 'Write failed'),
+    -21: ('EREAD', 'Read failed'),
+    -22: ('EAPPKEY', 'Invalid application key; request not processed'),
+}
+
+
 class RequestError(Exception):
     """
     Error in API request
     """
-    # TODO add error response messages
-    pass
+    def __init__(self, message):
+        code = message
+        self.code = code
+        code_desc, long_desc = _CODE_TO_DESCRIPTIONS[code]
+        self.message = f'{code_desc}, {long_desc}'
+
+    def __str__(self):
+        return self.message
diff --git a/src/tests/test_errors.py b/src/tests/test_errors.py
index e69de29..4469349 100644
--- a/src/tests/test_errors.py
+++ b/src/tests/test_errors.py
@@ -0,0 +1,17 @@
+import pytest
+
+from mega.errors import RequestError, _CODE_TO_DESCRIPTIONS
+
+
+@pytest.mark.parametrize(
+    'code, exp_message', [
+        (code, f'{desc[0]}, {desc[1]}')
+        for code, desc in _CODE_TO_DESCRIPTIONS.items()
+    ]
+)
+def test_request_error(code, exp_message):
+    exc = RequestError(code)
+
+    assert exc.code == code
+    assert exc.message == exp_message
+    assert str(exc) == exp_message