Ensure At Least One Blank Line Between Old and New Changelog Content

.github/pull_request_template.md

@@ -10,7 +10,7 @@ Please fill in the following content to let us know better about this change.
 ## Checklist
 
 - [ ] Add test cases to all the changes you introduce
-- [ ] Run `./script/format` and `./script/test` locally to ensure this change passes linter check and test
+- [ ] Run `./scripts/format` and `./scripts/test` locally to ensure this change passes linter check and test
 - [ ] Test the changes on the local machine manually
 - [ ] Update the documentation for the changes
 

.pre-commit-config.yaml

@@ -5,14 +5,14 @@ repos:
     hooks:
       - id: check-vcs-permalinks
       - id: end-of-file-fixer
-        exclude: "tests/[test_*|data|commands/tests_*]/*"
+        exclude: "tests/((commands|data)/|test_).+"
       - id: trailing-whitespace
         args: [--markdown-linebreak-ext=md]
       - id: debug-statements
       - id: no-commit-to-branch
 
-  - repo: https://github.com/Woile/commitizen
-    rev: v1.23.0
+  - repo: https://github.com/commitizen-tools/commitizen
+    rev: v2.24.0 # automatically updated by Commitizen
     hooks:
       - id: commitizen
         stages: [commit-msg]

commitizen/changelog.py

@@ -235,11 +235,11 @@ def get_metadata(filepath: str) -> Dict:
     }
 
 
-def incremental_build(new_content: str, lines: List, metadata: Dict) -> List:
+def incremental_build(new_content: str, lines: List[str], metadata: Dict) -> List[str]:
     """Takes the original lines and updates with new_content.
 
-    The metadata holds information enough to remove the old unreleased and
-    where to place the new content
+    The metadata governs how to remove the old unreleased section and where to place the
+    new content.
 
     Args:
         lines: The lines from the changelog
@@ -253,7 +253,7 @@ def incremental_build(new_content: str, lines: List, metadata: Dict) -> List:
     unreleased_end = metadata.get("unreleased_end")
     latest_version_position = metadata.get("latest_version_position")
     skip = False
-    output_lines: List = []
+    output_lines: List[str] = []
     for index, line in enumerate(lines):
         if index == unreleased_start:
             skip = True
@@ -270,16 +270,14 @@ def incremental_build(new_content: str, lines: List, metadata: Dict) -> List:
         if skip:
             continue
 
-        if (
-            isinstance(latest_version_position, int)
-            and index == latest_version_position
-        ):
-
-            output_lines.append(new_content)
-            output_lines.append("\n")
+        if index == latest_version_position:
+            output_lines.extend([new_content, "\n"])
 
         output_lines.append(line)
     if not isinstance(latest_version_position, int):
+        if output_lines and output_lines[-1].strip():
+            # Ensure at least one blank line between existing and new content.
+            output_lines.append("\n")
         output_lines.append(new_content)
     return output_lines
 

pyproject.toml

@@ -3,7 +3,8 @@ version = "2.24.0"
 tag_format = "v$version"
 version_files = [
   "pyproject.toml:version",
-  "commitizen/__version__.py"
+  "commitizen/__version__.py",
+  ".pre-commit-config.yaml:rev.\\s+(?=[^\\n]+Commitizen)"
 ]
 
 [tool.black]

tests/commands/test_changelog_command.py

@@ -320,6 +320,30 @@ def test_changelog_multiple_incremental_do_not_add_new_lines(
     assert out.startswith("#")
 
 
+@pytest.mark.usefixtures("tmp_commitizen_project")
+def test_changelog_incremental_newline_separates_new_content_from_old(
+    mocker, changelog_path
+):
+    """Test for https://github.com/commitizen-tools/commitizen/issues/509"""
+    with open(changelog_path, "w") as f:
+        f.write("Pre-existing content that should be kept\n")
+
+    create_file_and_commit("feat: add more cat videos")
+
+    testargs = ["cz", "changelog", "--incremental"]
+
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    with open(changelog_path, "r") as f:
+        out = f.read()
+
+    assert (
+        out
+        == "Pre-existing content that should be kept\n\n## Unreleased\n\n### Feat\n\n- add more cat videos\n"
+    )
+
+
 def test_changelog_without_revision(mocker, tmp_commitizen_project):
     changelog_file = tmp_commitizen_project.join("CHANGELOG.md")
     changelog_file.write(