diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
new file mode 100644
index 0000000..3c77778
--- /dev/null
+++ b/.github/workflows/test.yaml
@@ -0,0 +1,15 @@
+name: test
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-go@v5
+      with:
+        go-version-file: ./go.mod
+    - run: go test -v ./...
+    - run: go build -v ./...
diff --git a/go.mod b/go.mod
index 07adb08..cca6f4d 100644
--- a/go.mod
+++ b/go.mod
@@ -7,6 +7,7 @@ toolchain go1.22.3
 require (
 	github.com/goccy/go-yaml v1.11.3
 	github.com/spf13/cobra v1.8.0
+	github.com/stretchr/testify v1.8.4
 	k8s.io/apimachinery v0.30.1
 	k8s.io/client-go v0.30.1
 )
@@ -25,6 +26,7 @@ require (
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/net v0.23.0 // indirect
 	golang.org/x/oauth2 v0.10.0 // indirect
@@ -37,6 +39,7 @@ require (
 	google.golang.org/protobuf v1.33.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/klog/v2 v2.120.1 // indirect
 	k8s.io/utils v0.0.0-20230726121419-3b25d923346b // indirect
 	sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd // indirect
diff --git a/pkg/kubernetes/kubeconfig_test.go b/pkg/kubernetes/kubeconfig_test.go
new file mode 100644
index 0000000..380cc7c
--- /dev/null
+++ b/pkg/kubernetes/kubeconfig_test.go
@@ -0,0 +1,113 @@
+package kubernetes_test
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/tools/clientcmd/api"
+
+	"github.com/ryota-sakamoto/kubernetes-on-multipass/pkg/kubernetes"
+)
+
+const baseKubeconfig = `apiVersion: v1
+kind: Config
+clusters:
+- cluster:
+    certificate-authority-data: aG9nZQ==
+    server: https://192.168.205.%[1]d:6443
+  name: kubernetes%[1]d
+contexts:
+- context:
+    cluster: kubernetes%[1]d
+    user: admin%[1]d
+  name: kubernetes%[1]d
+current-context: kubernetes%[1]d
+users:
+- name: admin%[1]d
+  user:
+    client-certificate-data: dGVzdAo=
+    client-key-data: YWJjCg==
+`
+
+func TestMergeKubeconfig(t *testing.T) {
+	tempDir, err := os.MkdirTemp("", "kom")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		os.RemoveAll(tempDir)
+	}()
+
+	makeTempKubeconfig(t, tempDir+"/kubeconfig1", fmt.Sprintf(baseKubeconfig, 1))
+	makeTempKubeconfig(t, tempDir+"/kubeconfig2", fmt.Sprintf(baseKubeconfig, 2))
+
+	mergedConfig, err := kubernetes.MergeKubeconfig([]string{tempDir + "/kubeconfig1", tempDir + "/kubeconfig2"})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	assert.EqualValues(t, &api.Config{
+		APIVersion: "",
+		Kind:       "",
+		Preferences: api.Preferences{
+			Colors:     false,
+			Extensions: make(map[string]runtime.Object),
+		},
+		Clusters: map[string]*api.Cluster{
+			"kubernetes1": {
+				LocationOfOrigin:         tempDir + "/kubeconfig1",
+				Server:                   "https://192.168.205.1:6443",
+				CertificateAuthorityData: []byte("hoge"),
+				Extensions:               make(map[string]runtime.Object),
+			},
+			"kubernetes2": {
+				LocationOfOrigin:         tempDir + "/kubeconfig2",
+				Server:                   "https://192.168.205.2:6443",
+				CertificateAuthorityData: []byte("hoge"),
+				Extensions:               make(map[string]runtime.Object),
+			},
+		},
+		Contexts: map[string]*api.Context{
+			"kubernetes1": {
+				LocationOfOrigin: tempDir + "/kubeconfig1",
+				Cluster:          "kubernetes1",
+				AuthInfo:         "admin1",
+				Extensions:       make(map[string]runtime.Object),
+			},
+			"kubernetes2": {
+				LocationOfOrigin: tempDir + "/kubeconfig2",
+				Cluster:          "kubernetes2",
+				AuthInfo:         "admin2",
+				Extensions:       make(map[string]runtime.Object),
+			},
+		},
+		CurrentContext: "kubernetes1",
+		AuthInfos: map[string]*api.AuthInfo{
+			"admin1": {
+				LocationOfOrigin:      tempDir + "/kubeconfig1",
+				ClientCertificateData: []byte("test\n"),
+				ClientKeyData:         []byte("abc\n"),
+				Extensions:            make(map[string]runtime.Object),
+			},
+			"admin2": {
+				LocationOfOrigin:      tempDir + "/kubeconfig2",
+				ClientCertificateData: []byte("test\n"),
+				ClientKeyData:         []byte("abc\n"),
+				Extensions:            make(map[string]runtime.Object),
+			},
+		},
+		Extensions: make(map[string]runtime.Object),
+	}, mergedConfig)
+}
+
+func makeTempKubeconfig(t *testing.T, path, content string) {
+	t.Helper()
+
+	err := os.WriteFile(path, []byte(content), 0644)
+	if err != nil {
+		t.Fatal(err)
+	}
+}