feat(git): add merge filter options

README.md

@@ -42,6 +42,8 @@ npx changelogen@latest [...args] [--dir <dir>]
 - `--output`: Changelog file name to create or update. Defaults to `CHANGELOG.md` and resolved relative to dir. Use `--no-output` to write to console only.
 - `--bump`: Determine semver change and update version in `package.json`.
 - `--release`. Bumps version in `package.json` and creates commit and git tags using local `git`. You can disable commit using `--no-commit` and tag using `--no-tag`. You can enable the automatic push of the new tag and release commit to your git repository by adding `--push`.
+- `--onlyMerges`: Use merge commits in changelog.
+- `--noMerges`: Exclude merge commits in changelog.
 - `--publish`. Publishes package as a new version on `npm`. You will need to set authorisation tokens separately via `.npmrc` or environment variables.
 - `--publishTag` Use custom npm tag for publishing (Default is `latest`)
 - `--nameSuffix`: Adds suffix to package name (Example: `--nameSuffix canary` renames `foo` to `foo-canary`)

src/commands/default.ts

@@ -38,7 +38,15 @@
   const logger = consola.create({ stdout: process.stderr });
   logger.info(`Generating changelog for ${config.from || ""}...${config.to}`);
 
-  const rawCommits = await getGitDiff(config.from, config.to);
+  let onlyMerges: boolean;
+  if (args.onlyMerges) {
+    onlyMerges = true;
+  }
+  if (args.noMerges) {
+    onlyMerges = false;
+  }
+
+  const rawCommits = await getGitDiff(config.from, config.to, onlyMerges);
 
   // Parse commits as conventional commits
   const commits = parseCommits(rawCommits, config)

src/git.ts

@@ -57,11 +57,20 @@
 
 export async function getGitDiff(
   from: string | undefined,
-  to = "HEAD"
+  to = "HEAD",
+  onlyMerges?: boolean
 ): Promise<RawGitCommit[]> {
+  let mergeFilter = "";
+  if (onlyMerges === true) {
+    mergeFilter = "--merges";
+  }
+  if (onlyMerges === false) {
+    mergeFilter = "--no-merges";
+  }
+
   // https://git-scm.com/docs/pretty-formats
   const r = execCommand(
-    `git --no-pager log "${from ? `${from}...` : ""}${to}" --pretty="----%n%s|%h|%an|%ae%n%b" --name-status`
+    `git --no-pager log "${from ? `${from}...` : ""}${to}" --pretty="----%n%s|%h|%an|%ae%n%b" --name-status ${mergeFilter}`
   );
   return r
     .split("----\n")