fix scheduled download tests (#2706)

* fix triggers for scheduled workflow

* more fix

* add missing repository checkout

* try fix label in template

* rewrite test infrastructure

* trigger issue generation

* try fix issue template

* try remove quotes

* remove buggy label

* try fix title

* cleanup

* add more test details

* reenable issue creation
Co-authored-by: Francisco Massa <fvsmassa@gmail.com>

.github/failed_schedule_issue_template.md

 ---
-title: Scheduled workflow {{ env.WORKFLOW }}/{{ env.JOB }} failed
-labels: bug, module: datasets
+title: Scheduled workflow failed
+labels:
+  - bug
+  - "module: datasets"
 ---
 
 Oh no, something went wrong in the scheduled workflow {{ env.WORKFLOW }}/{{ env.JOB }}. 

.github/workflows/tests-schedule.yml

@@ -2,9 +2,10 @@ name: tests
 
 on:
   pull_request:
-    - "test/test_datasets_download.py"
-    - ".github/failed_schedule_issue_template.md"
-    - ".github/workflows/tests-schedule.yml"
+    paths:
+      - "test/test_datasets_download.py"
+      - ".github/failed_schedule_issue_template.md"
+      - ".github/workflows/tests-schedule.yml"
 
   schedule:
     - cron: "0 9 * * *"
@@ -22,20 +23,23 @@ jobs:
       - name: Upgrade pip
         run: python -m pip install --upgrade pip
 
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
       - name: Install PyTorch from the nightlies
         run: |
           pip install numpy
           pip install --pre torch torchvision -f https://download.pytorch.org/whl/nightly/cpu/torch_nightly.html
 
       - name: Install tests requirements
-        run: pip install pytest pytest-subtests
+        run: pip install pytest
 
       - name: Run tests
-        run: pytest test/test_datasets_download.py
+        run: pytest --durations=20 -ra test/test_datasets_download.py
 
       - uses: JasonEtco/create-an-issue@v2.4.0
         name: Create issue if download tests failed
-        if: failure()
+        if: failure() && github.event_name == 'schedule'
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           REPO: ${{ github.repository }}

test/test_datasets_download.py

 import contextlib
 import itertools
 import time
-import unittest
 import unittest.mock
 from datetime import datetime
 from os import path
 from urllib.parse import urlparse
 from urllib.request import urlopen, Request
 
+import pytest
+
 from torchvision import datasets
 from torchvision.datasets.utils import download_url, check_integrity
 
@@ -43,89 +44,94 @@ def limit_requests_per_time(min_secs_between_requests=2.0):
 urlopen = limit_requests_per_time()(urlopen)
 
 
-class DownloadTester(unittest.TestCase):
-    @staticmethod
-    @contextlib.contextmanager
-    def log_download_attempts(patch=True):
-        urls_and_md5s = set()
-        with unittest.mock.patch(
-            "torchvision.datasets.utils.download_url", wraps=None if patch else download_url
-        ) as mock:
-            try:
-                yield urls_and_md5s
-            finally:
-                for args, kwargs in mock.call_args_list:
-                    url = args[0]
-                    md5 = args[-1] if len(args) == 4 else kwargs.get("md5")
-                    urls_and_md5s.add((url, md5))
-
-    @staticmethod
-    def retry(fn, times=1, wait=5.0):
-        msgs = []
-        for _ in range(times + 1):
-            try:
-                return fn()
-            except AssertionError as error:
-                msgs.append(str(error))
-                time.sleep(wait)
-        else:
-            raise AssertionError(
-                "\n".join(
-                    (
-                        f"Assertion failed {times + 1} times with {wait:.1f} seconds intermediate wait time.\n",
-                        *(f"{idx}: {error}" for idx, error in enumerate(msgs, 1)),
-                    )
+@contextlib.contextmanager
+def log_download_attempts(patch=True):
+    urls_and_md5s = set()
+    with unittest.mock.patch("torchvision.datasets.utils.download_url", wraps=None if patch else download_url) as mock:
+        try:
+            yield urls_and_md5s
+        finally:
+            for args, kwargs in mock.call_args_list:
+                url = args[0]
+                md5 = args[-1] if len(args) == 4 else kwargs.get("md5")
+                urls_and_md5s.add((url, md5))
+
+
+def retry(fn, times=1, wait=5.0):
+    msgs = []
+    for _ in range(times + 1):
+        try:
+            return fn()
+        except AssertionError as error:
+            msgs.append(str(error))
+            time.sleep(wait)
+    else:
+        raise AssertionError(
+            "\n".join(
+                (
+                    f"Assertion failed {times + 1} times with {wait:.1f} seconds intermediate wait time.\n",
+                    *(f"{idx}: {error}" for idx, error in enumerate(msgs, 1)),
                 )
             )
-
-    @staticmethod
-    def assert_response_ok(response, url=None, ok=200):
-        msg = f"The server returned status code {response.code}"
-        if url is not None:
-            msg += f"for the the URL {url}"
-        assert response.code == ok, msg
-
-    @staticmethod
-    def assert_is_downloadable(url):
-        request = Request(url, headers=dict(method="HEAD"))
-        response = urlopen(request)
-        DownloadTester.assert_response_ok(response, url)
-
-    @staticmethod
-    def assert_downloads_correctly(url, md5):
-        with get_tmp_dir() as root:
-            file = path.join(root, path.basename(url))
-            with urlopen(url) as response, open(file, "wb") as fh:
-                DownloadTester.assert_response_ok(response, url)
-                fh.write(response.read())
-
-            assert check_integrity(file, md5=md5), "The MD5 checksums mismatch"
-
-    def test_download(self):
-        assert_fn = (
-            lambda url, _: self.assert_is_downloadable(url)
-            if self.only_test_downloadability
-            else self.assert_downloads_correctly
         )
-        for url, md5 in self.collect_urls_and_md5s():
-            with self.subTest(url=url, md5=md5):
-                self.retry(lambda: assert_fn(url, md5))
 
-    def collect_urls_and_md5s(self):
-        raise NotImplementedError
 
-    @property
-    def only_test_downloadability(self):
-        return True
+def assert_server_response_ok(response, url=None):
+    msg = f"The server returned status code {response.code}"
+    if url is not None:
+        msg += f"for the the URL {url}"
+    assert 200 <= response.code < 300, msg
+
+
+def assert_url_is_accessible(url):
+    request = Request(url, headers=dict(method="HEAD"))
+    response = urlopen(request)
+    assert_server_response_ok(response, url)
+
+
+def assert_file_downloads_correctly(url, md5):
+    with get_tmp_dir() as root:
+        file = path.join(root, path.basename(url))
+        with urlopen(url) as response, open(file, "wb") as fh:
+            assert_server_response_ok(response, url)
+            fh.write(response.read())
+
+        assert check_integrity(file, md5=md5), "The MD5 checksums mismatch"
+
+
+class DownloadConfig:
+    def __init__(self, url, md5=None, id=None):
+        self.url = url
+        self.md5 = md5
+        self.id = id or url
+
+
+def make_parametrize_kwargs(download_configs):
+    argvalues = []
+    ids = []
+    for config in download_configs:
+        argvalues.append((config.url, config.md5))
+        ids.append(config.id)
+
+    return dict(argnames="url, md5", argvalues=argvalues, ids=ids)
+
+
+def places365():
+    with log_download_attempts(patch=False) as urls_and_md5s:
+        for split, small in itertools.product(("train-standard", "train-challenge", "val"), (False, True)):
+            with places365_root(split=split, small=small) as places365:
+                root, data = places365
+
+                datasets.Places365(root, split=split, small=small, download=True)
+
+    return [DownloadConfig(url, md5=md5, id=f"Places365, {url}") for url, md5 in urls_and_md5s]
 
 
-class Places365Tester(DownloadTester):
-    def collect_urls_and_md5s(self):
-        with self.log_download_attempts(patch=False) as urls_and_md5s:
-            for split, small in itertools.product(("train-standard", "train-challenge", "val"), (False, True)):
-                with places365_root(split=split, small=small) as places365:
-                    root, data = places365
+@pytest.mark.parametrize(**make_parametrize_kwargs(itertools.chain(places365(),)))
+def test_url_is_accessible(url, md5):
+    retry(lambda: assert_url_is_accessible(url))
 
-                    datasets.Places365(root, split=split, small=small, download=True)
 
-        return urls_and_md5s
+@pytest.mark.parametrize(**make_parametrize_kwargs(itertools.chain()))
+def test_file_downloads_correctly(url, md5):
+    retry(lambda: assert_file_downloads_correctly(url, md5))