Allow specifying the location for the branch number in the branch name template. (#73)

Previously the branch number was always at the end after `/`. This PR
generalizes it and allows it to be present anywhere in the template
under the placeholder "$ID".

Fixes #57.

Author: ZolotukhinM

README.md

@@ -250,7 +250,10 @@ These arguments can be used with any subcommand:
 - `-T, --target`: Remote target branch (default: "main")
 - `--hyperlinks/--no-hyperlinks`: Enable/disable hyperlink support (default: enabled)
 - `-V, --verbose`: Enable verbose output from Git subcommands (default: false)
-- `--branch-name-template`: Template for generated branch names (default: "$USERNAME/stack")
+- `--branch-name-template`: Template for generated branch names (default: "$USERNAME/stack"). The following variables are supported:
+   - `$USERNAME`: The username of the current user
+   - `$BRANCH`: The current branch name
+   - `$ID`: The location for the ID of the branch. The ID is determined by the order of creation of the branches. If `$ID` is not found in the template, the template will be appended with `/$ID`.
 
 ### Subcommands
 

src/stack_pr/cli.py

@@ -286,7 +286,7 @@ def pprint(self, links: bool):
         s = b(self.commit.commit_id()[:8])
         pr_string = None
         if self.has_pr():
-            pr_string = blue("#" + self.pr.split("/")[-1])
+            pr_string = blue("#" + last(self.pr))
         else:
             pr_string = red("no PR")
         branch_string = None
@@ -384,16 +384,6 @@ def split_header(s: str) -> List[CommitHeader]:
     return [CommitHeader(h) for h in s.split("\0")[:-1]]
 
 
-def is_valid_ref(ref: str, branch_name_template: str) -> bool:
-    ref = ref.strip("'")
-
-    branch_name_base = get_branch_name_base(branch_name_template)
-    splits = ref.rsplit("/", 1)
-    if len(splits) < 2:
-        return False
-    return splits[-2].endswith(branch_name_base) and splits[-1].isnumeric()
-
-
 def last(ref: str, sep: str = "/") -> str:
     return ref.rsplit(sep, 1)[-1]
 
@@ -559,6 +549,13 @@ def add_or_update_metadata(e: StackEntry, needs_rebase: bool, verbose: bool) ->
     return True
 
 
+def fix_branch_name_template(branch_name_template: str):
+    if "$ID" not in branch_name_template:
+        return f"{branch_name_template}/$ID"
+
+    return branch_name_template
+
+
 @cache
 def get_branch_name_base(branch_name_template: str):
     username = get_gh_username()
@@ -568,31 +565,54 @@ def get_branch_name_base(branch_name_template: str):
     return branch_name_base
 
 
+def get_branch_id(branch_name_template: str, branch_name: str):
+    branch_name_base = get_branch_name_base(branch_name_template)
+    pattern = branch_name_base.replace(r"$ID", r"(\d+)")
+    match = re.search(pattern, branch_name)
+    if match:
+        return match.group(1)
+    return None
+
+
+def generate_branch_name(branch_name_template: str, branch_id: int):
+    branch_name_base = get_branch_name_base(branch_name_template)
+    branch_name = branch_name_base.replace(r"$ID", branch_id)
+    return branch_name
+
+
+def get_taken_branch_ids(refs: List[str], branch_name_template: str) -> List[int]:
+    branch_ids = list(get_branch_id(branch_name_template, ref) for ref in refs)
+    branch_ids = [int(branch_id) for branch_id in branch_ids if branch_id is not None]
+    return branch_ids
+
+
+def generate_available_branch_name(refs: List[str], branch_name_template: str) -> str:
+    branch_ids = get_taken_branch_ids(refs, branch_name_template)
+    max_ref_num = max(branch_ids) if branch_ids else 0
+    new_branch_id = max_ref_num + 1
+    return generate_branch_name(branch_name_template, str(new_branch_id))
+
+
 def get_available_branch_name(remote: str, branch_name_template: str) -> str:
     branch_name_base = get_branch_name_base(branch_name_template)
 
+    git_command_branch_template = branch_name_base.replace(r"$ID", "*")
     refs = get_command_output(
         [
             "git",
             "for-each-ref",
-            f"refs/remotes/{remote}/{branch_name_base}",
+            f"refs/remotes/{remote}/{git_command_branch_template}",
             "--format='%(refname)'",
         ]
     ).split()
 
-    def check_ref(ref):
-        return is_valid_ref(ref, branch_name_base)
-
-    refs = list(filter(check_ref, refs))
-    max_ref_num = max(int(last(ref.strip("'"))) for ref in refs) if refs else 0
-    new_branch_id = max_ref_num + 1
+    refs = list([ref.strip("'") for ref in refs])
+    return generate_available_branch_name(refs, branch_name_template)
 
-    return f"{branch_name_base}/{new_branch_id}"
 
-
-def get_next_available_branch_name(name: str) -> str:
-    base, id = name.rsplit("/", 1)
-    return f"{base}/{int(id) + 1}"
+def get_next_available_branch_name(branch_name_template: str, name: str) -> str:
+    id = get_branch_id(branch_name_template, name)
+    return generate_branch_name(branch_name_template, str(int(id) + 1))
 
 
 def set_head_branches(
@@ -604,7 +624,9 @@ def set_head_branches(
     available_name = get_available_branch_name(remote, branch_name_template)
     for e in filter(lambda e: not e.has_head(), st):
         e.head = available_name
-        available_name = get_next_available_branch_name(available_name)
+        available_name = get_next_available_branch_name(
+            branch_name_template, available_name
+        )
 
 
 def init_local_branches(
@@ -1359,6 +1381,8 @@ def main():
         parser.print_help()
         return
 
+    # Make sure "$ID" is present in the branch name template and append it if not
+    args.branch_name_template = fix_branch_name_template(args.branch_name_template)
     common_args = CommonArgs.from_args(args)
 
     if common_args.verbose:

tests/test_misc.py

@@ -0,0 +1,83 @@
+import sys
+from pathlib import Path
+
+sys.path.append(str(Path(__file__).parent.parent / "src"))
+
+from stack_pr.cli import (
+    get_branch_id,
+    generate_branch_name,
+    get_taken_branch_ids,
+    get_gh_username,
+    generate_available_branch_name,
+)
+
+import pytest
+
+
+@pytest.fixture(scope="module")
+def username():
+    return get_gh_username()
+
+
+@pytest.mark.parametrize(
+    "template,branch_name,expected",
+    [
+        ("feature-$ID-desc", "feature-123-desc", "123"),
+        ("$USERNAME/stack/$ID", "{username}/stack/99", "99"),
+        ("$USERNAME/stack/$ID", "refs/remote/origin/{username}/stack/99", "99"),
+    ],
+)
+def test_get_branch_id(username, template, branch_name, expected):
+    branch_name = branch_name.format(username=username)
+    assert get_branch_id(template, branch_name) == expected
+
+
+@pytest.mark.parametrize(
+    "template,branch_name",
+    [
+        ("feature/$ID/desc", "feature/abc/desc"),
+        ("feature/$ID/desc", "wrong/format"),
+        ("$USERNAME/stack/$ID", "{username}/main/99"),
+    ],
+)
+def test_get_branch_id_no_match(username, template, branch_name):
+    branch_name = branch_name.format(username=username)
+    assert get_branch_id(template, branch_name) is None
+
+
+def test_generate_branch_name():
+    template = "feature/$ID/description"
+    assert generate_branch_name(template, "123") == "feature/123/description"
+
+
+def test_get_taken_branch_ids():
+    template = "User/stack/$ID"
+    refs = [
+        "refs/remotes/origin/User/stack/104",
+        "refs/remotes/origin/User/stack/105",
+        "refs/remotes/origin/User/stack/134",
+    ]
+    assert get_taken_branch_ids(refs, template) == [104, 105, 134]
+    refs = ["User/stack/104", "User/stack/105", "User/stack/134"]
+    assert get_taken_branch_ids(refs, template) == [104, 105, 134]
+    refs = ["User/stack/104", "AAAA/stack/105", "User/stack/134", "User/stack/bbb"]
+    assert get_taken_branch_ids(refs, template) == [104, 134]
+
+
+def test_generate_available_branch_name():
+    template = "User/stack/$ID"
+    refs = [
+        "refs/remotes/origin/User/stack/104",
+        "refs/remotes/origin/User/stack/105",
+        "refs/remotes/origin/User/stack/134",
+    ]
+    assert generate_available_branch_name(refs, template) == "User/stack/135"
+    refs = []
+    assert generate_available_branch_name(refs, template) == "User/stack/1"
+    template = "User-stack-$ID"
+    refs = [
+        "refs/remotes/origin/User-stack-104",
+        "refs/remotes/origin/User-stack-105",
+        "refs/remotes/origin/User-stack-134",
+    ]
+    assert generate_available_branch_name(refs, template) == "User-stack-135"