Issue 7461 - Include source page into warning text for unresolved links

tests/test_page_outputs.py

 import logging
 import os
 import sys
 import runpy
 
 import mock
 import pytest
 
 from .conftest import ROOTPATH
 from .utils import get_dir_contents, exception_test
@@ skipping 53 matching lines @@
 def test_cache(output_pages):
     source = FileSource(os.path.join('test_site'))
     assert source.get_cache_dir() == os.path.join('test_site', 'cache')
 
 
 def test_broken_link_warnings(temp_site, tmpdir_factory, caplog):
     caplog.set_level(logging.WARNING)
     generate_static_pages(temp_site, tmpdir_factory)
     messages = {t[2] for t in caplog.record_tuples}
     expected_messages = [
-        'Link to "missing" (from "brokenlink") cannot be resolved',
-        'Link to "missing" (from "brokenlink-html") cannot be resolved',
-        'Link to "missing" (from "brokenlink-tmpl") cannot be resolved',
+        'Link from "brokenlink" to "missing" cannot be resolved',
+        'Link from "brokenlink-html" to "missing" cannot be resolved',
+        'Link from "brokenlink-tmpl" to "missing" cannot be resolved',
     ]
     for message in expected_messages:
         assert message in messages

[rhowell, 2019/04/12 20:17:12]

NIT: This test might be a bit stricter if we used something like
`set(expected_messages) == messages`, but it seems there's two extra broken
links in there (that might've been my fault). Would it make sense to clean up
those broken links? It's these two:

Link to "rel_path.html" (from "rel_path") cannot be resolved
Link to "myscripts.js" (from "rel_path") cannot be resolved

[Vasily Kuznetsov, 2019/04/15 16:48:45]

Yes, I thought about it too. In the end I decided to not do anything about it:
- For the purposes of this test we're just checking that broken links get
reported properly, so if there are some other messages that we don't expect,
that's fine.
- I haven't  looked too deep into it but I assume `rel_path` needs those links
for testing path rewriting -- I thought I'd rather not meddle there without a
good reason.

[rhowell, 2019/04/16 01:46:58]

Makes sense.

+    raise messages
 
 
 @pytest.mark.parametrize('filename,expected_output', dynamic_expected_outputs)
 def test_dynamic_server_handler(filename, expected_output, temp_site):
 
     def cleanup(page):
         return page.replace(os.linesep, '').strip()
 
     handler = DynamicServerHandler('localhost', 5000, str(temp_site))
     environ = {'PATH_INFO': filename}
 
     generated_page = handler(environ, lambda x, y: None)
 
     assert cleanup(expected_output) == cleanup(generated_page[0])
 
 
 @pytest.mark.parametrize('page', ['en/translate', '/en/translate'])
 def test_dynamic_server_handler_with_conflicts(page, temp_site_with_conflicts):
     handler = DynamicServerHandler('localhost', 5000,
                                    str(temp_site_with_conflicts))
     environ = {'PATH_INFO': page}
     exp_msg = 'The requested page conflicts with another page.'
 
     exception_test(handler, Exception, exp_msg, environ, lambda x, y: None)