feat(git): test root commit with one tag

.github/fixtures/test-latest-with-one-tag/commit.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -e
 
-GIT_COMMITTER_DATE="2021-01-23 01:23:45" git commit --allow-empty -m "Initial commit"
+GIT_COMMITTER_DATE="2021-01-23 01:23:45" git commit --allow-empty -m "feat: initial commit"
 
 GIT_COMMITTER_DATE="2021-01-23 01:23:46" git commit --allow-empty -m "feat: add feature 1"
 git tag v0.1.0

.github/fixtures/test-latest-with-one-tag/expected.md

@@ -6,6 +6,7 @@ All notable changes to this project will be documented in this file.
 
 ### Feat
 
+- Initial commit
 - Add feature 1
 
 <!-- generated by git-cliff -->

git-cliff-core/src/repo.rs

@@ -472,6 +472,18 @@ mod test {
 		.to_string())
 	}
 
+	fn get_root_commit_hash() -> Result<String> {
+		Ok(str::from_utf8(
+			Command::new("git")
+				.args(["rev-list", "--max-parents=0", "HEAD"])
+				.output()?
+				.stdout
+				.as_ref(),
+		)?
+		.trim_ascii_end()
+		.to_string())
+	}
+
 	fn get_last_tag() -> Result<String> {
 		Ok(str::from_utf8(
 			Command::new("git")
@@ -594,6 +606,16 @@ mod test {
 		Ok(())
 	}
 
+	#[test]
+	fn includes_root_commit() -> Result<()> {
+		let repository = get_repository()?;
+		let commits = repository.commits(None, true, None, None)?;
+		let root_commit =
+			AppCommit::from(&commits.last().expect("no commits found").clone());
+		assert_eq!(get_root_commit_hash()?, root_commit.id);
+		Ok(())
+	}
+
 	fn create_temp_repo() -> (Repository, TempDir) {
 		let temp_dir =
 			TempDir::with_prefix("git-cliff-").expect("failed to create temp dir");