Support git's shallow clone

README.md

@@ -38,7 +38,7 @@ Clone a repository:
 
     git = require 'gift'
 
-    git.clone "git@host:path/to/remote/repo.git", "path/to/local/clone/repo", (err, _repo) ->
+    git.clone "git@host:path/to/remote/repo.git", "path/to/local/clone/repo", depth, (err, _repo) ->
       repo = _repo
       # => #<Repo>
 

src/index.coffee

@@ -32,10 +32,14 @@ Git.init = (path, bare, callback) ->
 #
 # repository - The repository to clone from.
 # path       - The directory to clone into.
+# depth      - The specified number of revisions of shallow clone
 # callback   - Receives `(err, repo)`.
 #
-Git.clone = (repository, path, callback) ->
-  bash = "git clone \"#{repository}\" \"#{path}\""
+Git.clone = (repository, path, depth = 0, callback) ->
+  if (0 == depth)
+    bash = "git clone \"#{repository}\" \"#{path}\""
+  else
+    bash = "git clone \"#{repository}\" \"#{path}\" --depth \"#{depth}\""
   exec bash, (err, stdout, stderr) ->
     return callback err if err
     return callback err, (new Repo path, false, { maxBuffer: Git.maxBuffer })

test/index.test.coffee

@@ -45,7 +45,7 @@ describe "git", ->
     repo = null
     newRepositoryDir = "#{__dirname}/fixtures/clone"
     before (done) ->
-      git.clone "https://github.com/notatestuser/gift.git", newRepositoryDir, (err, _repo) ->
+      git.clone "https://github.com/notatestuser/gift.git", newRepositoryDir, 1, (err, _repo) ->
         repo = _repo
         done err
     it "clone a repository", (done) ->