_examples: Add sparse checkout example.

Author: onee-only

COMPATIBILITY.md

@@ -34,6 +34,7 @@ compatibility status with go-git.
 | `merge`     |             | ⚠️ (partial) | Fast-forward only                       |                                                                                                 |
 | `mergetool` |             | ❌           |                                         |                                                                                                 |
 | `stash`     |             | ❌           |                                         |                                                                                                 |
+| `sparse-checkout`     |             | ✅           |                                         | - [sparse-checkout](_examples/sparse-checkout/main.go)                                                                                               |
 | `tag`       |             | ✅           |                                         | - [tag](_examples/tag/main.go) <br/> - [tag create and push](_examples/tag-create-push/main.go) |
 
 ## Sharing and updating projects

_examples/common_test.go

@@ -33,6 +33,7 @@ var args = map[string][]string{
 	"revision":                   {cloneRepository(defaultURL, tempFolder()), "master~2^"},
 	"sha256":                     {tempFolder()},
 	"showcase":                   {defaultURL, tempFolder()},
+	"sparse-checkout":            {defaultURL, "vendor", tempFolder()},
 	"tag":                        {cloneRepository(defaultURL, tempFolder())},
 }
 

_examples/sparse-checkout/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"os"
+
+	"github.com/go-git/go-git/v5"
+	. "github.com/go-git/go-git/v5/_examples"
+)
+
+func main() {
+	CheckArgs("<url>", "<sparse_path>", "<directory>")
+	url := os.Args[1]
+	path := os.Args[2]
+	directory := os.Args[3]
+
+	Info("git clone %s %s", url, directory)
+
+	r, err := git.PlainClone(directory, false, &git.CloneOptions{
+		URL:        url,
+		NoCheckout: true,
+	})
+	CheckIfError(err)
+
+	w, err := r.Worktree()
+	CheckIfError(err)
+
+	err = w.Checkout(&git.CheckoutOptions{
+		SparseCheckoutDirectories: []string{path},
+	})
+	CheckIfError(err)
+}