Merge lp:~jelmer/brz/rewrite-url into lp:brz

[Jelmer Vernooij]

Add a hook for URL dereferencing.

Add a hook for URL dereferencing.

[Martin Packman (gz)]

I'm a bit scared this is too low-level a hook to sensibly support as we want to hack location stuff around a fair bit still, but I guess we're not offering *that* much on external compatibility guarantees at present.

review: Approve

=== modified file 'breezy/location.py'
--- breezy/location.py	2018-11-23 23:51:34 +0000
+++ breezy/location.py	2019-02-09 10:34:29 +0000
@@ -22,12 +22,27 @@
 from . import (
     urlutils,
     )
+from .hooks import Hooks
 from .sixish import (
     PY3,
     string_types,
     )
 
 
+class LocationHooks(Hooks):
+    """Dictionary mapping hook name to a list of callables for location hooks.
+    """
+
+    def __init__(self):
+        Hooks.__init__(self, "breezy.location", "hooks")
+        self.add_hook(
+            'rewrite_url',
+            "Called with a URL to rewrite.", (3, 0))
+
+
+hooks = LocationHooks()
+
+
 def location_to_url(location):
     """Determine a fully qualified URL from a location string.
 
@@ -61,4 +76,7 @@
     if not urlutils.is_url(location):
         return urlutils.local_path_to_url(location)
 
+    for hook in hooks['rewrite_url']:
+        location = hook(location)
+
     return location
 
=== modified file 'breezy/tests/test_location.py'
--- breezy/tests/test_location.py	2018-11-23 23:51:34 +0000
+++ breezy/tests/test_location.py	2019-02-09 10:34:29 +0000
@@ -23,6 +23,7 @@
     )
 from ..directory_service import directories
 from ..location import (
+    hooks as location_hooks,
     location_to_url,
     )
 
@@ -73,3 +74,13 @@
 
     def test_absolute_file_url(self):
         self.assertEqual("file:///bar", location_to_url("file:/bar"))
+
+    def test_rewrite_hook(self):
+        self.assertEqual(
+            'http://foo.example.com/blah', location_to_url('http://foo.example.com/blah'))
+        def rewrite_url(url):
+            return url.replace('foo', 'bar')
+        self.addCleanup(location_hooks.uninstall_named_hook, 'rewrite_url', 'test')
+        location_hooks.install_named_hook('rewrite_url', rewrite_url, 'test')
+        self.assertEqual(
+            'http://bar.example.com/bar', location_to_url('http://foo.example.com/foo'))