reverse slug and uuid order in filenames

Change-Id: I7346f6bd9965db3680143c0f5bdd0448d12e05eb

releasenotes/notes/reverse-slug-order-4c5f94e72d4f6fb9.yaml

@@ -0,0 +1,9 @@
+---
+upgrade:
+  - |
+    Change the order of the slug and UUID value in the note filename so
+    the slug comes before the UUIUD to make tab completion easier to
+    use.
+
+    Older files are still supported, and can be renamed to use
+    the new style.

reno/create.py

@@ -43,7 +43,7 @@ def _pick_note_file_name(notesdir, slug):
     "Pick a unique name in notesdir."
     for i in range(50):
         newid = utils.get_random_string()
-        notefilename = os.path.join(notesdir, '%s-%s.yaml' % (newid, slug))
+        notefilename = os.path.join(notesdir, '%s-%s.yaml' % (slug, newid))
         if not os.path.exists(notefilename):
             return notefilename
     else:

reno/scanner.py

@@ -62,6 +62,17 @@ def _file_exists_at_commit(reporoot, filename, sha):
     return bool(get_file_at_commit(reporoot, filename, sha))
 
 
+def _get_unique_id(filename):
+    base = os.path.basename(filename)
+    root, ext = os.path.splitext(base)
+    uniqueid = root[-16:]
+    if '-' in uniqueid:
+        # This is an older file with the UUID at the beginning
+        # of the name.
+        uniqueid = root[:16]
+    return uniqueid
+
+
 # TODO(dhellmann): Add branch arg?
 def get_notes_by_version(reporoot, notesdir, branch=None):
 
@@ -81,9 +92,9 @@ def get_notes_by_version(reporoot, notesdir, branch=None):
     current_version = _get_current_version(reporoot, branch)
     # print('current_version = %s' % current_version)
 
-    # Remember the most current filename for each prefix, to allow for
+    # Remember the most current filename for each id, to allow for
     # renames.
-    last_name_by_prefix = {}
+    last_name_by_id = {}
 
     # FIXME(dhellmann): This might need to be more line-oriented for
     # longer histories.
@@ -119,23 +130,22 @@ def get_notes_by_version(reporoot, notesdir, branch=None):
         if current_version not in versions:
             versions.append(current_version)
 
-        # Remember the files seen, using their prefix as a unique id.
+        # Remember the files seen, using their UUID suffix as a unique id.
         for f in filenames:
             # Updated as older tags are found, handling edits to release
             # notes.
-            prefix = os.path.basename(f)[:16]
-            earliest_seen[prefix] = tags[0]
-            if prefix in last_name_by_prefix:
-                # We already have a filename for this prefix from a
+            uniqueid = _get_unique_id(f)
+            earliest_seen[uniqueid] = tags[0]
+            if uniqueid in last_name_by_id:
+                # We already have a filename for this id from a
                 # new commit, so use that one in case the name has
                 # changed.
                 continue
             if _file_exists_at_commit(reporoot, f, sha):
                 # Remember this filename as the most recent version of
-                # the unique prefix we have seen, in case the name
+                # the unique id we have seen, in case the name
                 # changed from an older commit.
-                last_name_by_prefix[prefix] = (f, sha)
-                # print('remembering %s as last name for %s' % (f, prefix))
+                last_name_by_id[uniqueid] = (f, sha)
 
     # Invert earliest_seen to make a list of notes files for each
     # version.
@@ -144,8 +154,8 @@ def get_notes_by_version(reporoot, notesdir, branch=None):
         files_and_tags[v] = []
     # Produce a list of the actual files present in the repository. If
     # a note is removed, this step should let us ignore it.
-    for prefix, version in earliest_seen.items():
-        base, sha = last_name_by_prefix[prefix]
+    for uniqueid, version in earliest_seen.items():
+        base, sha = last_name_by_id[uniqueid]
         files_and_tags[version].append((base, sha))
     for version, filenames in files_and_tags.items():
         files_and_tags[version] = list(reversed(filenames))

reno/tests/test_scanner.py

@@ -128,9 +128,12 @@ class Base(base.TestCase):
         self._run_git('add', '.')
         self._run_git('commit', '-m', message)
 
-    def _add_notes_file(self, slug='slug', commit=True):
+    def _add_notes_file(self, slug='slug', commit=True, legacy=False):
         n = self.get_note_num()
-        basename = '%016x-%s.yaml' % (n, slug)
+        if legacy:
+            basename = '%016x-%s.yaml' % (n, slug)
+        else:
+            basename = '%s-%016x.yaml' % (slug, n)
         filename = os.path.join(self.reporoot, 'releasenotes', 'notes',
                                 basename)
         create._make_note_file(filename)
@@ -362,6 +365,70 @@ class BasicTest(Base):
             results,
         )
 
+    def test_legacy_file(self):
+        self._make_python_package()
+        self._run_git('tag', '-s', '-m', 'first tag', '1.0.0')
+        f1 = self._add_notes_file('slug1', legacy=True)
+        self._run_git('tag', '-s', '-m', 'first tag', '2.0.0')
+        f2 = f1.replace('slug1', 'slug2')
+        self._run_git('mv', f1, f2)
+        self._git_commit('rename note file')
+        raw_results = scanner.get_notes_by_version(
+            self.reporoot,
+            'releasenotes/notes',
+        )
+        results = {
+            k: [f for (f, n) in v]
+            for (k, v) in raw_results.items()
+        }
+        self.assertEqual(
+            {'2.0.0': [f2],
+             '2.0.0-1': [],
+             },
+            results,
+        )
+
+    def test_rename_legacy_file_to_new(self):
+        self._make_python_package()
+        self._run_git('tag', '-s', '-m', 'first tag', '1.0.0')
+        f1 = self._add_notes_file('slug1', legacy=True)
+        self._run_git('tag', '-s', '-m', 'first tag', '2.0.0')
+        # Rename the file with the new convention of placing the UUID
+        # after the slug instead of before.
+        f2 = f1.replace('0000000000000001-slug1',
+                        'slug1-0000000000000001')
+        self._run_git('mv', f1, f2)
+        self._git_commit('rename note file')
+        raw_results = scanner.get_notes_by_version(
+            self.reporoot,
+            'releasenotes/notes',
+        )
+        results = {
+            k: [f for (f, n) in v]
+            for (k, v) in raw_results.items()
+        }
+        self.assertEqual(
+            {'2.0.0': [f2],
+             '2.0.0-1': [],
+             },
+            results,
+        )
+
+
+class UniqueIdTest(Base):
+
+    def test_legacy(self):
+        uid = scanner._get_unique_id(
+            'releasenotes/notes/0000000000000001-slug1.yaml'
+        )
+        self.assertEqual('0000000000000001', uid)
+
+    def test_modern(self):
+        uid = scanner._get_unique_id(
+            'releasenotes/notes/slug1-0000000000000001.yaml'
+        )
+        self.assertEqual('0000000000000001', uid)
+
 
 class BranchTest(Base):