Update warning, add tests for project requirements check

* Make warning more general for differences between PEP 508 and pip
* Add tests for _check_requirements

spacy/cli/project/run.py

@@ -344,9 +344,8 @@ def _check_requirements(requirements: List[str]) -> Tuple[bool, bool]:
             conflicting_pkgs_msgs.append(vc.report())
         except Exception:
             msg.warn(f"Unable to check requirement: {req} "
-                     "Check that the requirement is formatted according to PEP "
-                     "440, in particular that URLs are formatted as "
-                     "'package_name @ URL'")
+                     "Checks are currently limited to requirement specifiers "
+                     "(PEP 508)")
 
     if len(failed_pkgs_msgs) or len(conflicting_pkgs_msgs):
         msg.warn(

spacy/tests/test_cli.py

@@ -1,5 +1,6 @@
 import os
 import math
+import pkg_resources
 from random import sample
 from typing import Counter
 
@@ -25,6 +26,7 @@ from spacy.cli.download import get_compatibility, get_version
 from spacy.cli.init_config import RECOMMENDATIONS, init_config, fill_config
 from spacy.cli.package import get_third_party_dependencies
 from spacy.cli.package import _is_permitted_package_name
+from spacy.cli.project.run import _check_requirements
 from spacy.cli.validate import get_model_pkgs
 from spacy.lang.en import English
 from spacy.lang.nl import Dutch
@@ -855,3 +857,35 @@ def test_span_length_freq_dist_output_must_be_correct():
     span_freqs = _get_spans_length_freq_dist(sample_span_lengths, threshold)
     assert sum(span_freqs.values()) >= threshold
     assert list(span_freqs.keys()) == [3, 1, 4, 5, 2]
+
+
+def test_project_check_requirements():
+    reqs = """
+    spacy
+
+    # comment
+
+    thinc"""
+    output = _check_requirements([req.strip() for req in reqs.split("\n")])
+    assert output == (False, False)
+
+    reqs = """# comment
+    --some-flag
+    spacy"""
+    output = _check_requirements([req.strip() for req in reqs.split("\n")])
+    assert output == (False, False)
+
+    reqs = """# comment
+    --some-flag
+    spacy; python_version >= '3.6'"""
+    output = _check_requirements([req.strip() for req in reqs.split("\n")])
+    assert output == (False, False)
+
+    # excessive guard against unlikely package name
+    try:
+        pkg_resources.require("spacyunknowndoesnotexist12345")
+    except pkg_resources.DistributionNotFound:
+        reqs = """# comment
+        spacyunknowndoesnotexist12345"""
+        output = _check_requirements([req.strip() for req in reqs.split("\n")])
+        assert output == (True, False)