chore: add testing to load offset

.pre-commit-config.yaml

@@ -1,4 +1,3 @@
----
 default_language_version:
   python: python3.11
 repos:

src/sync_pre_commit_lock/pre_commit_config.py

@@ -77,21 +77,18 @@ def repos_normalized(self) -> set[PreCommitRepo]:
 
     @cached_property
     def document_start_offset(self) -> int:
-        # Use re to split by lines and find the '---'
+        """Return the line number where the YAML document starts."""
+
         lines = self.raw_file_contents.split("\n")
         for i, line in enumerate(lines):
             # Trim leading/trailing whitespaces
-            line = line.strip()
+            line = line.rstrip()
             # Skip if line is a comment or empty/whitespace
             if line.startswith("#") or line == "":
                 continue
             # If line is '---', return line number + 1
             if line == "---":
                 return i + 1
-            # If line isn't a comment and not '---' or empty/whitespace, it's the start of the YAML doc
-            # We return the line number (add 1 for 1-based indexing)
-            else:
-                return i
         return 0
 
     def update_pre_commit_repo_versions(self, new_versions: dict[PreCommitRepo, str]) -> None:
@@ -112,17 +109,15 @@ def update_pre_commit_repo_versions(self, new_versions: dict[PreCommitRepo, str]
             if normalized_repo not in new_versions:
                 continue
 
-            rev_line_number = rev.end_line + self.document_start_offset
-            rev_line_idx = rev_line_number - 1
+            rev_line_number: int = rev.end_line + self.document_start_offset
+            rev_line_idx: int = rev_line_number - 1
             original_rev_line: str = updated_lines[rev_line_idx]
-
             updated_lines[rev_line_idx] = original_rev_line.replace(str(rev), new_versions[normalized_repo])
 
         changes = difflib.ndiff(original_lines, updated_lines)
         change_count = sum(1 for change in changes if change[0] in ["+", "-"])
 
         if change_count == 0:
-            # XXX We should probably raise an exception here
-            return
+            raise RuntimeError("No changes to write, this should not happen")
         with self.pre_commit_config_file_path.open("w") as stream:
             stream.writelines(updated_lines)

tests/fixtures/sample_pre_commit_config/pre-commit-config-document-separator.yaml

@@ -11,7 +11,7 @@ repos:
       - id: check-toml
 
   - repo: https://github.com/psf/black
-    rev: 23.3.0
+    rev: 23.2.0
     hooks:
       - id: black
 
@@ -20,3 +20,14 @@ repos:
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]
+
+  - repo: local
+    hooks:
+      - id: mypy
+        name: mypy
+        entry: mypy
+        args: [src, tests, --color-output]
+        language: system
+        types: [python]
+        pass_filenames: false
+        require_serial: true

tests/fixtures/sample_pre_commit_config/pre-commit-config-start-empty-lines.yaml

@@ -1,7 +1,6 @@
 
 
 
-
 default_language_version:
   python: python3.11
 repos:

tests/fixtures/sample_pre_commit_config/pre-commit-config-with-local.yaml

@@ -1,3 +1,4 @@
+
 ---
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit

tests/fixtures/sample_pre_commit_config/pre-commit-config.yaml

@@ -24,5 +24,3 @@ repos:
     rev: 23.3.0
     hooks:
       - id: black
-
-# XXX Fix the issue with documents

tests/test_config.py

@@ -4,7 +4,6 @@
 from sync_pre_commit_lock.db import RepoInfo
 
 
-# @patch('sync_pre_commit_lock.config.SyncPreCommitLockConfig.__dataclass_fields__', new_callable=MagicMock)
 def test_from_toml() -> None:
     data = {
         "disable-sync-from-lock": True,

tests/test_pre_commit_config_file.py

@@ -47,3 +47,30 @@ def test_repos_property() -> None:
     assert config.repos[0].repo == "https://repo1.local:443/test"
     assert config.repos[0].rev == "rev1"
     assert config.repos_normalized == {PreCommitRepo("https://repo1.local/test", "rev1")}
+
+
+FIXTURES = Path(__file__).parent / "fixtures" / "sample_pre_commit_config"
+
+
+@pytest.mark.parametrize(
+    ("path", "offset"),
+    [
+        (FIXTURES / "pre-commit-config-document-separator.yaml", 4),
+        (FIXTURES / "pre-commit-config-start-empty-lines.yaml", 0),
+        (FIXTURES / "pre-commit-config-with-local.yaml", 2),
+        (FIXTURES / "pre-commit-config.yaml", 1),
+        (FIXTURES / "sample-django-stubs.yaml", 0),
+    ],
+)
+def test_files_offset(path: Path, offset: int) -> None:
+    config = PreCommitHookConfig.from_yaml_file(path)
+    assert config.document_start_offset == offset
+
+
+def test_update_versions():
+    config = PreCommitHookConfig.from_yaml_file(FIXTURES / "pre-commit-config-document-separator.yaml")
+    config.pre_commit_config_file_path = MagicMock()
+
+    config.update_pre_commit_repo_versions({PreCommitRepo("https://github.com/psf/black", "23.2.0"): "23.3.0"})
+    # Assert open was called with "w" mode
+    assert config.pre_commit_config_file_path.open.call_args[0][0] == "w"