Add PackageFinder.process_project_url(), and test.

src/pip/_internal/index/package_finder.py

@@ -779,6 +779,25 @@ class PackageFinder(object):
 
         return candidates
 
+    def process_project_url(self, project_url, link_evaluator):
+        # type: (Link, LinkEvaluator) -> List[InstallationCandidate]
+        logger.debug(
+            'Fetching project page and analyzing links: %s', project_url,
+        )
+        html_page = self._link_collector.fetch_page(project_url)
+        if html_page is None:
+            return []
+
+        page_links = list(parse_links(html_page))
+
+        with indent_log():
+            package_links = self.evaluate_links(
+                link_evaluator,
+                links=page_links,
+            )
+
+        return package_links
+
     def find_all_candidates(self, project_name):
         # type: (str) -> List[InstallationCandidate]
         """Find all available InstallationCandidate for project_name
@@ -789,8 +808,7 @@ class PackageFinder(object):
         See LinkEvaluator.evaluate_link() for details on which files
         are accepted.
         """
-        link_collector = self._link_collector
-        collected_links = link_collector.collect_links(project_name)
+        collected_links = self._link_collector.collect_links(project_name)
 
         link_evaluator = self.make_link_evaluator(project_name)
 
@@ -801,21 +819,10 @@ class PackageFinder(object):
 
         page_versions = []
         for project_url in collected_links.project_urls:
-            logger.debug(
-                'Fetching project page and analyzing links: %s', project_url,
+            package_links = self.process_project_url(
+                project_url, link_evaluator=link_evaluator,
             )
-            html_page = link_collector.fetch_page(project_url)
-            if html_page is None:
-                continue
-
-            page_links = list(parse_links(html_page))
-
-            with indent_log():
-                new_versions = self.evaluate_links(
-                    link_evaluator,
-                    links=page_links,
-                )
-                page_versions.extend(new_versions)
+            page_versions.extend(package_links)
 
         file_versions = self.evaluate_links(
             link_evaluator,

tests/unit/test_finder.py

@@ -473,6 +473,22 @@ class TestLinkEvaluator(object):
         assert actual == (False, expected_msg)
 
 
+def test_process_project_url(data):
+    project_name = 'simple'
+    index_url = data.index_url('simple')
+    project_url = Link('{}/{}'.format(index_url, project_name))
+    finder = make_test_finder(index_urls=[index_url])
+    link_evaluator = finder.make_link_evaluator(project_name)
+    actual = finder.process_project_url(
+        project_url, link_evaluator=link_evaluator,
+    )
+
+    assert len(actual) == 1
+    package_link = actual[0]
+    assert package_link.project == 'simple'
+    assert str(package_link.version) == '1.0'
+
+
 def test_find_all_candidates_nothing():
     """Find nothing without anything"""
     finder = make_test_finder()