Allow for easier committing from subdirectories

fixes #29

Author: s0

.changeset/mean-trainers-develop.md

@@ -0,0 +1,10 @@
+---
+"@changesets/ghcommit": minor
+---
+
+Introduce `addDirectory` option for `commitChangesFromRepo` to allow users to
+specify a subdirectory of the git repository that should be used to add files
+from, rather then adding all changed files.
+
+This is useful when trying to emulate the behavior of running `git add .`
+from a subdirectory of the repository.

.changeset/old-kings-collect.md

@@ -0,0 +1,11 @@
+---
+"@changesets/ghcommit": minor
+---
+
+Automatically find root in `commitChangesFromRepo`
+when `repoDirectory` is unspecified.
+
+While this does result in a behavioral change for an existing argument,
+it's considered non-breaking as before `commitChangesFromRepo` would just not
+work when run from a subdirectory of a repo when `repoDirectory` was not
+specified.

src/git.ts

@@ -9,14 +9,17 @@ import {
 
 export const commitChangesFromRepo = async ({
   base,
-  repoDirectory = process.cwd(),
+  repoDirectory,
+  addDirectory,
   log,
   ...otherArgs
 }: CommitChangesFromRepoArgs): Promise<CommitFilesResult> => {
   const ref = base?.commit ?? "HEAD";
+  const resolvedRepoDirectory =
+    repoDirectory ?? (await git.findRoot({ fs, filepath: process.cwd() }));
   const gitLog = await git.log({
     fs,
-    dir: repoDirectory,
+    dir: resolvedRepoDirectory,
     ref,
     depth: 1,
   });
@@ -37,7 +40,7 @@ export const commitChangesFromRepo = async ({
   };
   await git.walk({
     fs,
-    dir: repoDirectory,
+    dir: addDirectory ?? resolvedRepoDirectory,
     trees,
     map: async (filepath, [commit, workdir]) => {
       const prevOid = await commit?.oid();
@@ -50,7 +53,7 @@ export const commitChangesFromRepo = async ({
       if (
         await git.isIgnored({
           fs,
-          dir: repoDirectory,
+          dir: resolvedRepoDirectory,
           filepath,
         })
       ) {

src/interface.ts

@@ -107,7 +107,17 @@ export interface CommitChangesFromRepoArgs extends CommitFilesBasedArgs {
   /**
    * The root of the repository.
    *
-   * @default process.cwd()
+   * When unspecified, the root of the repository will be found by recursively
+   * searching for the `.git` directory from the current working directory.
    */
   repoDirectory?: string;
+  /**
+   * Which directory to add the files from.
+   *
+   * Useful for monorepos where you want to add files from a specific directory only.
+   *
+   * Defaults to resolved value as {@link repoDirectory},
+   * which will add all changed files in the repository.
+   */
+  addDirectory?: string;
 }