Add tests for low-level data acquisition from DWD

tests/provider/dwd/observation/test_download.py

@@ -0,0 +1,60 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2018-2021, earthobservations developers.
+# Distributed under the MIT License. See LICENSE for more info.
+import re
+import zipfile
+
+import pytest
+
+from wetterdienst.exceptions import FailedDownload, ProductFileNotFound
+from wetterdienst.provider.dwd.observation.download import (
+    __download_climate_observations_data,
+)
+
+
+def test_download_climate_observations_data_failure_invalid_url():
+    with pytest.raises(FailedDownload) as ex:
+        __download_climate_observations_data("foobar.txt")
+    assert ex.match(re.escape("Download failed for foobar.txt: InvalidURL(foobar.txt)"))
+
+
+def test_download_climate_observations_data_failure_invalid_protocol():
+    with pytest.raises(FailedDownload) as ex:
+        __download_climate_observations_data("foobar://bazqux.txt")
+    assert ex.match(
+        re.escape("Download failed for foobar://bazqux.txt: AssertionError()")
+    )
+
+
+def test_download_climate_observations_data_failure_invalid_zip():
+    with pytest.raises(zipfile.BadZipFile) as ex:
+        __download_climate_observations_data("http://example.org")
+    assert ex.match(
+        re.escape("The Zip archive http://example.org seems to be corrupted")
+    )
+
+
+def test_download_climate_observations_data_failure_broken_zip():
+    with pytest.raises(zipfile.BadZipFile) as ex:
+        __download_climate_observations_data(
+            "https://github.com/earthobservations/testdata/raw/main/opendata.dwd.de/climate_environment/CDC/observations_germany/climate/daily/kl/recent/broken-zip-archive.zip"
+        )
+    assert ex.match("The Zip archive .+ seems to be corrupted")
+
+
+def test_download_climate_observations_data_failure_empty_zip():
+    with pytest.raises(ProductFileNotFound) as ex:
+        __download_climate_observations_data(
+            "https://github.com/earthobservations/testdata/raw/main/opendata.dwd.de/climate_environment/CDC/observations_germany/climate/daily/kl/recent/empty-zip-archive.zip"
+        )
+    assert ex.match("The archive .+ does not contain a 'produkt\\*' file")
+
+
+def test_download_climate_observations_data_valid():
+    payload = __download_climate_observations_data(
+        "https://github.com/earthobservations/testdata/raw/main/opendata.dwd.de/climate_environment/CDC/observations_germany/climate/daily/kl/recent/tageswerte_KL_00011_akt.zip"
+    )
+    assert payload.startswith(
+        b"STATIONS_ID;MESS_DATUM;QN_3;  FX;  FM;QN_4; RSK;RSKF; SDK;SHK_TAG;  NM; VPM;"
+        b"  PM; TMK; UPM; TXK; TNK; TGK;eor\r\n         11;20200227;   10;  28.5;   "
+    )

wetterdienst/provider/dwd/observation/download.py

@@ -1,13 +1,13 @@
 # -*- coding: utf-8 -*-
 # Copyright (c) 2018-2021, earthobservations developers.
 # Distributed under the MIT License. See LICENSE for more info.
+import logging
 from concurrent.futures import ThreadPoolExecutor
 from io import BytesIO
 from typing import List, Tuple
 from zipfile import BadZipFile
 
 from fsspec.implementations.zip import ZipFileSystem
-from requests.exceptions import InvalidURL
 
 from wetterdienst.exceptions import (
     FailedDownload,
@@ -17,6 +17,9 @@
 from wetterdienst.util.cache import CacheExpiry
 from wetterdienst.util.network import download_file
 
+log = logging.getLogger(__name__)
+
+
 PRODUCT_FILE_IDENTIFIER = "produkt"
 
 
@@ -57,12 +60,11 @@ def __download_climate_observations_data(remote_file: str) -> bytes:
 
     try:
         file = download_file(remote_file, ttl=CacheExpiry.FIVE_MINUTES)
-    except InvalidURL as e:
-        raise InvalidURL(
-            f"Error: the station data {remote_file} could not be reached."
-        ) from e
-    except Exception:
-        raise FailedDownload(f"Download failed for {remote_file}")
+    except Exception as ex:
+        ex_type = ex.__class__.__name__
+        msg = f"Download failed for {remote_file}: {ex_type}({ex})"
+        log.exception(msg)
+        raise FailedDownload(msg)
 
     try:
         zf = ZipFileSystem(file)
@@ -73,15 +75,15 @@ def __download_climate_observations_data(remote_file: str) -> bytes:
         # Raise exceptions if no corresponding file was found or if there are multiple product files.
         if not product_files:
             raise ProductFileNotFound(
-                f"The archive {remote_file} does not contain a '{PRODUCT_FILE_IDENTIFIER}*' file."
+                f"The archive {remote_file} does not contain a '{PRODUCT_FILE_IDENTIFIER}*' file"
             )
         elif len(product_files) > 1:
             raise MultipleProductFilesFound(
-                f"The archive {remote_file} contains multiple product files, which is ambiguous."
+                f"The archive {remote_file} contains multiple product files, which is ambiguous"
             )
 
         file_in_bytes = zf.open(product_files[0]).read()
         return file_in_bytes
 
     except BadZipFile as e:
-        raise BadZipFile(f"The archive of {remote_file} seems to be corrupted.") from e
+        raise BadZipFile(f"The Zip archive {remote_file} seems to be corrupted") from e