publish: raise an error on redirects

Resolves: #3069

poetry/publishing/uploader.py

@@ -265,13 +265,24 @@ class Uploader:
                         allow_redirects=False,
                         headers={"Content-Type": monitor.content_type},
                     )
-                if dry_run or resp.ok:
+                if dry_run or 200 <= resp.status_code < 300:
                     bar.set_format(
                         " - Uploading <c1>{0}</c1> <fg=green>%percent%%</>".format(
                             file.name
                         )
                     )
                     bar.finish()
+                elif resp.status_code == 301:
+                    if self._io.output.supports_ansi():
+                        self._io.overwrite(
+                            " - Uploading <c1>{0}</c1> <error>{1}</>".format(
+                                file.name, "FAILED"
+                            )
+                        )
+                    raise UploadError(
+                        "Redirects are not supported. "
+                        "Is the URL missing a trailing slash?"
+                    )
             except (requests.ConnectionError, requests.HTTPError) as e:
                 if self._io.output.supports_ansi():
                     self._io.overwrite(

tests/publishing/test_uploader.py

@@ -34,6 +34,18 @@ def test_uploader_properly_handles_403_errors(http):
     assert "HTTP Error 403: Forbidden" == str(e.value)
 
 
+def test_uploader_properly_handles_301_redirects(http):
+    http.register_uri(http.POST, "https://foo.com", status=301, body="Redirect")
+    uploader = Uploader(Factory().create_poetry(project("simple_project")), NullIO())
+
+    with pytest.raises(UploadError) as e:
+        uploader.upload("https://foo.com")
+
+    assert "Redirects are not supported. Is the URL missing a trailing slash?" == str(
+        e.value
+    )
+
+
 def test_uploader_registers_for_appropriate_400_errors(mocker, http):
     register = mocker.patch("poetry.publishing.uploader.Uploader._register")
     http.register_uri(